Below is a list of changes for each Finagle release.

Note that PHAB_ID=# and RB_ID=# correspond to associated messages in commits.



Bug Fixes

  • finagle-integration: we discovered that we had a dead code in MuxClientSession. Let’s remove Timer as a parameter in MuxClientSession since it’s a dead code. PHAB_ID=D869538


Breaking API Changes

  • finagle-core: Removed the stack param WhenNoNodesOpenParam from LoadBalancerFactory. Removed NoNodesOpenServiceFactory and NoNodesOpenException. When the majority of nodes are busy or closed (approx 60%), the load balancer will probabilistically fail open and pick a node at random. PHAB_ID=D843176

Runtime Behavior Changes

  • finagle: Bump version of Jackson to 2.13.2. PHAB_ID=D848592


New Features

  • finagle-logging: Introduced finagle-logging, a new module for SLF4J-integrated filters. PHAB_ID=D813291
  • finagle-logging: Introduced SlowTracesFilter, which observes your requests and logs the slowest ones that are also sampled for tracing. PHAB_ID=D813291
  • finagle-core: Introduced MinSendBackupAfterMs to the stack param Configured in BackupRequestFilter and propagated changes to MethodBuilder by adding new versions of idempotent function. When traffic load is low, this is useful to increase the delay when backup requests are sent and prevent the client from sending unnecessary backup requests. PHAB_ID=D825503
  • finagle-core: Added a new annotation clnt/has_dark_request in tracing and Finagle Local context. The new annotation can be used to indicate whether or not the request has a span that is sent to dark service. PHAB_ID=D825317

Bug Fixes

  • finagle-netty4-http: On a Request, adding multiple cookies with the same name to a CookieMap preserves all of them. Only cookies on Responses are deduplicated. Previously, adding a Request cookie with the same name would overwrite the old value with the new value. PHAB_ID=D801466
  • finagle-postgres: Fixed a bug where a single framer instance was shared across all connections to a host when using TLS. PHAB_ID=D768581
  • finagle-core: Fixed a bug where InetResolver was leaking memory while resolving non-existing address, even if no one is still asking for it. PHAB_ID=D771608

Breaking API Changes

  • finagle-core: Changed the shouldInvoke parameter in method serviceConcurrently and sendDarkRequest in AbstractDarkRequestFilter to be a Boolean instead of a function of (Req => Boolean). PHAB_ID=D825317
  • finagle-core: Renamed the existing clnt/dark_request to clnt/is_dark_request in c.t.finagle.filter.DarkTrafficFilter``PHAB_ID=D825317``

Runtime Behavior Changes

  • finagle: Bump version of Caffeine to 2.9.3. PHAB_ID=D815761
  • finagle: Upgrade to Netty 4.1.73.Final and netty-tcnative 2.0.46.Final.``PHAB_ID=D788382``
  • finagle-core: in TimeoutFilter, only transform a timeout exception caused by TimeoutFilter. This also changes the type of exception raised by the TimeoutFilter from a java.util.concurrent.TimeoutException to a com.twitter.finagle.RequestTimeoutException. PHAB_ID=D814094
  • finagle-mux: Exceptions raised when Mux negotiation has failed have been moved to a Debug log level as the stack trace is generally long and not necessarily helpful. The logged message now includes the remote address and that is logged at both the Debug level (with the exception and stack trace) and Warning level (without). PHAB_ID=D821661
  • finagle-core: c.t.f.ssl.SslConfigurations.initializeSslContext now creates an engine which includes TLSv1.3 as a supported protocol. PHAB_ID=D814211
  • finagle-netty4: c.t.f.n.ssl.client.Netty4ClientSslConfigurations.createClientContext and c.t.f.n.ssl.server.Netty4ServerSslConfigurations.createServerContext now create contexts using the provided cipher suites. PHAB_ID=D732258


Runtime Behavior Changes

  • finagle: Bump version of Jackson to 2.13.1. PHAB_ID=D808049



  • finagle-zipkin-core: c.t.f.zipkin.core.Sampler.DefaultSampleRate is deprecated in favor of c.t.f.zipkin.core.DefaultSampler.sampleRate. PHAB_ID=D795303

Bug Fixes

  • finagle-zipkin-core: c.t.f.zipkin.core.Sampler would sample at 1/10,000 rate when configured with a lower (but non-zero) rate. It can now sample at rates as low as 1/16,777,216. PHAB_ID=D792693

Runtime Behavior Changes

  • finagle-zipkin-scribe: c.t.f.zipkin.thrift.ZipkinTracer uses c.t.f.zipkin.core.DefaultSampler.sampleRate as the default sample rate instead of deprecated c.t.f.zipkin.core.Sampler.DefaultSampleRate. This allows it to correctly observe user-configured overrides to the default sample rate. When a ZipkinTracer is constructed with default parameters and there are no user-configured overrides, the behavior is unchanged. PHAB_ID=D795303


  • finagle-base-http: Promote several classes out of exp experimental package: c.t.f.http.{GenStreamingSerialServerDispatcher, IdentityStreamTransport, StreamTransport} along with internal support classes. PHAB_ID=D782933

New Features

  • finagle-memcached: Add public object c.t.f.memcached.KeyValidation with a validKey method to allow validation of keys before passing them to various methods where invalid ones will cause exceptions to be thrown. PHAB_ID=D782660

Breaking API Changes

  • finagle-core: Remove c.t.f.loadbalancer.Balancer.maxEffort. Remove the maxEffort argument from Balancers.{p2c, p2cPeakEwma, aperture, aperturePeakEwmaUse, roundRobin}. PHAB_ID=D772863
  • finagle-core: c.t.f.tracing.ClientRequestTracingFilter has been removed. Record relevant tracing information in your service or client directly. PHAB_ID=D777298
  • finagle: Remove com.twitter.finagle.Group, and other rarely used and deprecated pieces that depend on it com.twitter.finagle.memcached.TwitterCacheResolver, com.twitter.finagle.memcached.CacheNodeGroup, com.twitter.finagle.memcached.RubyMemCacheClient, and com.twitter.finagle.memcached.PHPMemCacheClient. Instead of Group, please use Var[Set[T]] or Activity[Set[T]] directly instead. PHAB_ID=D776745

Runtime Behavior Changes

  • finagle: Update Caffeine cache library to version 2.9.2 PHAB_ID=D771893
  • finagle-netty4: The current SOCKS and HTTP proxies support going through an HTTP proxy first, and then a SOCKS proxy. It seems more common to do the other way around, so we’re going to instead support going through a SOCKS proxy and then an HTTP proxy, and drop support for the reverse. PHAB_ID=D713485


Breaking API Changes

  • finagle-core: c.t.f.loadbalancer.distributor.AddressedFactory has been removed. Use

c.t.f.loadbalancer.EndpointFactory directly instead. PHAB_ID=D751145

Runtime Behavior Changes

  • finagle-core: Moved c.t.finagle.stats.LoadedStatsReceiver and c.t.finagle.stats.DefaultStatsReceiver from the finagle-core module to util-stats. PHAB_ID=D763497


New Features

Breaking API Changes

  • finagle-thrift: Removed c.t.finagle.thrift.ThriftClient#newMethodIface and ThriftClient#thriftService, use c.t.f.thrift.ThriftClient#methodPerEndpoint. PHAB_ID=D747744

Bug Fixes

  • finagle-core/partitioning: Close balancers and their gauges when repartitioning. PHAB_ID=D731675

Runtime Behavior Changes

  • finagle: Upgrade to Netty 4.1.67.Final and netty-tcnative 2.0.40.Final. PHAB_ID=D726343
  • finagle: Downgrade to Netty 4.1.66.Final PHAB_ID=D746041
  • finagle: Bump version of Jackson to 2.11.4. PHAB_ID=D727879
  • finagle-core: OffloadFilter hands off work from Netty I/O thread to the offload CPU thread pool right after we enter the Finagle stack by default. Previously this could be enabled via a toggle. The com.twitter.finagle.OffloadEarly toggle has been removed. PHAB_ID=D733526

21.8.0 (No 21.7.0 Release)

New Features

  • finagle-mysql: introduce newRichClient(dest: String, label: String) method, which removes the need for extra boilerplate to convert the destination String to a c.t.finagle.Name when specifying both dest and label in String form. PHAB_ID=D706140
  • finagle-http, finagle-thriftmux: introduce client.withSni() API. Use this api to specify an SNI hostname for TLS clients. PHAB_ID=D712652
  • finagle-postgresql: introduce withStatementTimeout, withConnectionInitializationCommands, and withSessionDefaults APIs to allow configuring sessions before they’re used. PHAB_ID=D746525

Runtime Behavior Changes

  • finagle: Update Caffeine cache library to version 2.9.1 PHAB_ID=D660908

  • finagle: Update ScalaCheck to version 1.15.4 PHAB_ID=D691691

  • finagle-core: change ServiceClosedException to extend FailureFlags and to be universally retryable PHAB_ID=710580

  • finagle-http: remove the com.twitter.finagle.http.UseH2, com.twitter.finagle.http.UseH2CClients2, com.twitter.finagle.http.UseH2CServers and com.twitter.finagle.http.UseHttp2MultiplexCodecClient toggles. The configuration for c.t.finagle.Http.client and c.t.finagle.Http.server now default to using the HTTP/2 based implementation. To disable this behavior, use c.t.finagle.Http.client.withNoHttp2 and c.t.finagle.Http.server.withNoHttp2 respectively.

    Alternatively, new GlobalFlag’s have been introduced to modify the default behavior of clients and servers that have not been explicitly configured, where the com.twitter.finagle.http.defaultClientProtocol and com.twitter.finagle.http.defaultServerProtocol flags can be set to HTTP/1.1 to modify the default client or server configuration, respectively. PHAB_ID=D625880`

  • finagle-netty4: Finagle now reuses Netty “boss” (or parent) threads instead of creating a new thread per server. Netty parent threads are servicing the server acceptor, a relatively lightweight component that listens for new incoming connections before handing them out to the global worker pool. PHAB_ID=D662116

  • finagle-http2: introduce optional parameter NackRstFrameHandling to enable or disable NACK conversion to RST_STREAM frames. PHAB_ID=D702696

  • finagle-thrift, finagle-thriftmux: clients may start reporting (correctly) lower success rate. Previously server exceptions not declared in IDL were erroneously considered as successes. The fgix also improves failure detection and thus nodes previously considered as healthy by failure accrual policy may be considered as unhealthy. PHAB_ID=D698272

Bug Fixes

  • finagle-core: Add BackupRequestFilter to client registry when configured. PHAB_ID=D686981
  • finagle-thrift, finagle-thriftmux: clients now treat server exceptions not declared in IDL as failures, rather than successes, and do not skip the configured response classifier for failure accrual. PHAB_ID=D698272


New Features

  • finagle-core: Introduce, which is a process-local Dtab that will NOT be remotely broadcast for any protocol, where Dtab.local will be broadcast for propagation on supported protocols. For path name resolution, the Dtab.local will take precedence over the, if the same path is defined in both, and both take precedence over the Dtab.base. The existing Dtab.local request propagation behavior remains unchanged. PHAB_ID=D677860
  • finagle-core: Add descriptions to RequestDraining, PrepFactory, PrepConn, and protoTracing modules in StackClient. Add descriptions to preparer and protoTracing modules in StackServer. PHAB_ID=D685887
  • finagle-mysql: Add support for MySQL 8.0’s default caching_sha2_password pluggable authentication. PHAB_ID=D676015

Breaking API Changes

  • finagle-memcached: Ketama Partitioned Client has been removed and the Partition Aware Memcached Client has been made the default. As part of this change, com.twitter.finagle.memcached.UsePartitioningMemcachedClient toggle has been removed, and it no longer applies. PHAB_ID=D661460
  • finagle-core: c.t.f.builder.ServerBuilder has been removed. Use the StackServer interfaces instead. PHAB_ID=D689067

Runtime Behavior Changes

  • finagle-core: Broadcast context keys lookups are now case insensitive. This change is backwards compatible as the marshalled key id is unchanged. Although enabled by default, this change will be temporarily sitting behind a toggle, com.twitter.finagle.context.MarshalledContextLookupId that can be used to turn off this change. PHAB_ID=D665209


  • finagle-core: The ServerBuilder pattern has been deprecated. Use the stack server pattern instead. PHAB_ID=D691414


New Features

  • finagle-http2: Added c.t.f.http2.param.EnforceMaxConcurrentStreams which allows users to configure http2 clients to buffer streams once a connection has hit the max concurrent stream limit rather than rejecting them. A buffered_streams gauge has been added to track the current number of buffered streams. PHAB_ID=D643138
  • finagle-mux: Added support for TLS snooping to the mux protocol. This allows a thriftmux server to start a connection as TLS or follow the existing upgrade pathway at the leisure of the client. This also allows the server to support opportunistic TLS and still downgrade to vanilla thrift. PHAB_ID=D584638
  • finagle-netty4: Added a new counter to keep track of the number of TLS connections that were started via snooping. PHAB_ID=D667652
  • finagle-thrift: Thrift(Mux) clients and servers now fill in a c.t.f.Thrift.param.ServiceClass stack param with the runtime class corresponding to a IDL-generated service stub. PHAB_ID=D676781

Breaking API Changes

  • finagle-core: c.t.f.param.Logger has been removed. Use external configuration supported by your logging backend to alter settings of com.twitter.finagle logger. PHAB_ID=D618667

Runtime Behavior Changes

  • finagle-http: Make handling of invalid URI consistent across client implementations. There are behavioral inconsistencies amongst the current HTTP client implementations:

    Our HTTP/1.x clients allow for submitting requests that contain non-ASCII characters and invalid character encoded sequences, while our HTTP/2 clients will either mangle the URI and strip out non-ASCII characters within the Netty pipeline or result in an UnknownChannelException when attempting to parse invalid character encoded sequences. With this change, we now consistently propagate an InvalidUriException result, which is marked as NonRetryable for all HTTP client implementations. All HTTP server implementations maintain behavior of returning a 400 Bad Request response status, but now also correctly handle invalid character encoded sequences. PHAB_ID=D660069

Bug Fixes

  • finagle-core: Failed writes on Linux due to a remote peer disconnecting should now be properly seen as a c.t.f.ChannelClosedException instead of a c.t.f.UnknownChannelException. PHAB_ID=D661550
  • finagle-http2: The streams gauge is now correctly added for http2 connections over TLS. PHAB_ID=D643138
  • finagle-core: c.t.f.n.NameTreeFactory will now discard empty elements in c.t.f.NameTree.Union’s with zero weight. PHAB_ID=D666635
  • finagle-http: All HTTP server implementations consistently return a 400 Bad Request response status when encountering a URI with invalid character encoded sequences. PHAB_ID=D660069


New Features

  • finagle-core: Introduce a new ResponseClassifier (‘IgnoreIRTEs’) that treats com.twitter.finagle.IndividualRequestTimeoutException`s as `ResponseClass.Ignored. This response classifier is useful when a client has set a super low RequestTimeout and receiving a response is seen as ‘best-effort’. PHAB_ID=D645818
  • finagle-mysql: Introduce support of opportunistic TLS to allow mysql clients with enabled TLS to speak over encrypted connections with MySQL servers where TLS is on, and fallback to plaintext connections if TLS is switched off on the server side. PHAB_ID=D644982

Runtime Behavior Changes

  • finagle-core: The “failures” counter is changed to be created eagerly, when no failure happens, the counter value is 0. PHAB_ID=D645590

Breaking API Changes

  • finagle-exception: This package was no longer used and therefore has been removed. No replacement is planned. PHAB_ID=D656591


New Features

  • finagle-core: Added value ForceWithDtab to flag -com.twitter.finagle.loadbalancer.exp.apertureEagerConnections that forces the aperture load balancer to eagerly connect, even in staging environments where Dtab locals are set. PHAB_ID=D613989
  • finagle-core: Introduce a new Backoff to create backoffs based on varies strategies, where backoffs are calculated on the fly, instead of being created once and memoized in a Stream. Also introduced Backoff.fromStream(Stream) and Backoff.toStream to help with migration to the new API. PHAB_ID=D592562
  • finagle-netty4: Upgrade to Netty 4.1.59.Final and TcNative 2.0.35.Final. PHAB_ID=D629268
  • finagle-http: Integrate Kerberos authentication filter to finagle http client and server. PHAB_ID=D634270 PHAB_ID=D621714
  • finagle-core: Provided c.t.f.ssl.TrustCredentials.X509Certificates to enable directly passing X509Certificate instead of passing a File. PHAB_ID=D641088

Breaking API Changes

  • finagle: Builds are now only supported for Scala 2.12+ PHAB_ID=D631091
  • finagle-base-http: Kerberos jaas config KerberosConfiguration is replaced with ServerKerberosConfiguration and ClientKerberosConfiguration concrete classes. PHAB_ID=D634270
  • finagle-core: Changed flag -com.twitter.finagle.loadbalancer.exp.apertureEagerConnections” from having Boolean values true or false to `EagerConnectionsType values Enable, Disable, and ForceWithDtab. PHAB_ID=D613989
  • finagle-mysql: The constructor of c.t.f.mysql.transport.MysqlBufReader now takes an underlying Prior uses of the constructor, which took a, should migrate to using c.t.f.mysql.transport.MysqlBufReader.apply instead. PHAB_ID=D622705

Runtime Behavior Changes

  • finagle: Revert to scala version 2.12.12 due to PHAB_ID=D635917
  • finagle: Bump scala version to 2.12.13 PHAB_ID=D632567
  • finagle-core: Move helper tracing methods like traceLocal in Trace into the Tracing class. This allows cheaper use of these APIs by first capturing a Trace via Trace#apply, avoiding the extra lookups that will add overhead on the request path. PHAB_ID=D633318.
  • finagle-core: c.t.finagle.InetResolver, c.t.finagle.builder.ClientBuilder, c.t.finagle.liveness.FailureAccrualFactory, c.t.finagle.liveness.FailureAccrualPolicy, c.t.finagle.param.ClientParams, c.t.finagle.param.SessionQualificationParams, c.t.finagle.service.FailFastFactory, c.t.finagle.service.RequeueFilter, c.t.finagle.service.Retries, c.t.finagle.service.RetryFilter, and c.t.finagle.service.RetryPolicy will accept the new c.t.finagle.service.Backoff to create backoffs. Services can convert a Stream to/from a Backoff with Backoff.fromStream(Stream) and Backoff.toStream. PHAB_ID=D592562
  • finagle-core: remove the com.twitter.finagle.loadbalancer.apertureEagerConnections Toggle and change the default behavior to enable eager connections for c.t.f.loadbalancer.ApertureLeastLoaded and c.t.f.loadbalancer.AperturePeakEwma load balancers. The state of the com.twitter.finagle.loadbalancer.apertureEagerConnections GlobalFlag now also defaults to enable this feature (Enable. You can disable this feature for all clients via setting the com.twitter.finagle.loadbalancer.apertureEagerConnections GlobalFlag to Disable for your process. (i.e. -com.twitter.finagle.loadbalancer.apertureEagerConnections=Disable). PHAB_ID=D625618
  • finagle-partitioning: Add EndpointMarkedDeadException. Before this change, the exception being thrown appeared as an anonymous class and it made deciphering it difficult when it came up in stats. Create a concrete class and throw that. PHAB_ID=D640835


  • finagle-core: Backoff.fromJava is marked as deprecated, since the new Backoff is java-friendly. For services using Stream.iterator on the old Backoff, please use the new API Backoff.toJavaIterator to acquire a java-friendly iterator. PHAB_ID=D592562


New Features

  • finagle-zipkin-core: Record zipkin.sampling_rate annotation to track sampling rate at trace roots. PHAB_ID=D601379
  • finagle-core: Added variant of c.t.f.Address.ServiceFactory.apply that does not require specifying c.t.f.Addr.Metadata and defaults to c.t.f.Addr.Metadata.empty. PHAB_ID=D605438
  • finagle-core: Added variant of c.t.f.Name.bound which takes a c.t.f.Service as a parameter. Tying a Name directly to a Service can be extremely useful for testing the functionality of a Finagle client. PHAB_ID=D605745
  • finagle-mux: Added variant of c.t.f.mux.Request.apply and c.t.f.mux.Requests.make which takes only the body of the Request (in the form of as a parameter. This is useful for when the path value of a Request is not used by the server (e.g. testing). PHAB_ID=D613686

Runtime Behavior Changes

  • finagle-memcached: The log level of messages pertaining to whether a Memcached client is using the older non-partitioned or the newer partitioned version has been lowered. These messages are no longer written at an ‘info’ level. PHAB_ID=D607487


New Features

Bug Fixes

  • finagle-core: Fix wraparound bug in Ring.weight, as reported by @nvartolomei PHAB_ID=D575958
  • finagle-mysql: Update the UTF8 character set to cover those added in MySQL 8. PHAB_ID=D590996
  • finagle-thriftmux: Fixed a bug where connections were not established eagerly in ThriftMux MethodBuilder even when eager connections was enabled. PHAB_ID=D589592

Runtime Behavior Changes

  • finagle-mysql: Don’t use the full query when adding tracing annotations. PHAB_ID=D593944


New Features

  • finagle-benchmark: Add a benchmark for LocalContext. PHAB_ID=D588632
  • finagle-core: Add a new filter, ClientExceptionTracingFilter, that records error annotations for completed spans. Annotations include error, exception.type, and exception.message. See for naming details. PHAB_ID=D583001
  • finagle-core: Add a new stat (histogram) that reports how long a task has been sitting in the offload queue. This instrumentation is sampled at the given interval (100ms by default) that can be overridden with a global flag com.twitter.finagle.offload.statsSampleInterval. PHAB_ID=D571980
  • finagle-core: Add a new experimental flag com.twitter.finagle.offload.queueSize that allows to put bounds on the offload queue. Any excess work that can’t be offloaded due to a queue overflow is run on IO (Netty) thread instead. Put this way, this flag enables the simplest form of backpressure on the link between Netty and OffloadFilter. PHAB_ID=D573328
  • finagle-netty4: Add ExternalClientEngineFactory to the open source version of Finagle. This SslClientEngineFactory acts as a better example of how to build custom client and server engine factories in order to reuse SSL contexts for performance concerns. PHAB_ID=D572567
  • finagle-core: Provide com.twitter.finagle.naming.DisplayBoundName for configuring how to display the bound Name for a given client in metrics metadata. PHAB_ID=D573905
  • finagle-core: Provide ClientParamsInjector, a class that will be service-loaded at run-time by Finagle clients, and will allow generic configuration of all sets of parameters. PHAB_ID=D574861

Breaking API Changes

  • finagle-core: Move DarkTrafficFilter and AbstractDarkTrafficFilter from the experimental finagle-exp to supported finagle-core. The package containing these classes changed from c.t.finagle.exp to c.t.finagle.filter. PHAB_ID=D572384
  • finagle-core, finagle-thrift: Move ForwardingWarmUpFilter and ThriftForwardingWarmUpFilter from the experimental finagle-exp to supported finagle-core, and finagle-thrift, respectively. The package containing ForwardingWarmUpFilter changed from c.t.finagle.exp to c.t.finagle.filter, and the package containing ThriftForwardingWarmUpFilter changed from c.t.finagle.exp to c.t.finagle.thrift.filter. PHAB_ID=D573545
  • finagle-core: FailureAccrualFactory.isSuccess has been replaced with the method def classify(ReqRep): ResponseClass to allow expressing that a failure should be ignored. PHAB_ID=D571093

Runtime Behavior Changes

  • finagle-core: Use Scala default implementation to calculate Hashcode and equals method for ServiceFactoryProxy. PHAB_ID=D569045
  • finagle: Update build.sbt to get aarch64 binaries and try the fast path acquire up to 5 times before failing over to the AbstractQueuedSynchronizer slow path in NonReentrantReadWriteLock for Arm64. PHAB_ID=D589167

Bug Fixes

  • finagle-core: Users should no longer see the problematic java.lang.UnsupportedOperationException: tail of empty stream when a c.t.f.s.RetryPolicy is converted to a String for showing. PHAB_ID=D582199


Breaking API Changes

  • finagle-thrift: Change the partition locator function getLogicalPartitionId in PartitioningStrategy from Int => Int to Int => Seq[Int], which supports many to many mapping from hosts and logical partitions. PHAB_ID=D550789

Runtime Behavior Changes

  • finagle-core: Disable eager connections for balancers with a non 1.0 weight. PHAB_ID=D567842


New Features

  • finagle-core: Add RelativeName field to Metric Metadata and populate it for client and server metrics. PHAB_ID=D552357
  • finagle-scribe: Add c.t.finagle.scribe.Publisher for publishing messages to a Scribe process. PHAB_ID=D539003
  • finagle-thrift/partitioning: Support dynamic resharding for partition aware thriftmux client. PHAB_ID=D543466

Runtime Behavior Changes

  • finagle: Bump version of Jackson to 2.11.2. PHAB_ID=D538440

Bug Fixes

  • finagle-core: The TraceId alternative constructor now forwards the traceIdHigh parameter to the primary constructor. PHAB_ID=D546612
  • finagle-core: Enforce ordering in RequestLogger to make sure we log the end of async action before higher modules have a chance to process the result. PHAB_ID=D551741
  • finagle-stats: Handle Double percentile rounding error in stat format. PHAB_ID=D554778


New Features

  • finagle-core: Populate SourceRole field of Metric Metadata for client and server metrics. PHAB_ID=D542596
  • finagle-thriftmux: Add MethodBuilder specific APIs for ThriftMux partition aware client. PHAB_ID=D531900
  • finagle-netty4: Upgrade to Netty 4.1.51.Final and TcNative 2.0.34.Final. PHAB_ID=D536904

20.8.0 (DO NOT USE)

Runtime Behavior Changes

  • finagle-netty4-http: Post, Put, Patch non-streaming outbound requests with empty bodies will be added the Content-Length header with value 0. PHAB_ID=D518010
  • finagle-core: A ServiceFactory created by ServiceFactory.const/constant propagates the wrapped service status. PHAB_ID=D520598
  • finagle-core: Only deposit into the RetryBudget after a request succeeds. This should help mitigate retry storm behavior. PHAB_ID=D528880
  • finagle-http: c.t.f.http.filter.PayloadSizeFilter no longer adds an annotation on each streaming chunk and instead aggregates the byte count and adds a single record on stream termination. PHAB_ID=D522543
  • finagle-zipkin-scribe: zipkin scribe log_span prefix replaced with scribe. zipkin-scribe/scribe/<stats>. PHAB_ID=D527531

New Features

  • finagle-core: introduce type-safe ReqRep variant PHAB_ID=D520027
  • finagle-core: Added a new variant of Filter.andThenIf which allows passing the parameters as individual parameters instead of a Scala tuple. PHAB_ID=D523010
  • finagle-core: new metric (counter) for traces that are sampled. finagle/tracing/sampled PHAB_ID=D522355
  • finagle-netty4: Add the c.t.f.netty4.Netty4Listener.MaxConnections param that can be used to limit the number of connections that a listener will maintain. Connections that exceed the limit are eagerly closed. PHAB_ID=D517737
  • finagle-thrift: Added java-friendly c.t.f.thrift.exp.partitioning.ClientHashingStrategy and c.t.f.thrift.exp.partitioning.ClientCustomStrategy create methods, and added java-friendly c.t.f.thrift.exp.partitioning.RequestMergerRegistry#addRequestMerger and c.t.f.thrift.exp.partitioning.ResponseMergerRegistry#addResponseMerger to make partitioning easier to use from Java. PHAB_ID=D525770

Breaking API Changes

  • finagle-core: ReqRep can no longer be created via new ReqRep(..). Please use ReqRep.apply(..) instead. PHAB_ID=D520027
  • finagle-thrift: Updated the c.t.f.thrift.exp.partitioning.ClientHashingStrategy and the c.t.f.thrift.exp.partitioning.ClientCustomStrategy to take constructor arguments instead of needing to override methods on construction. PHAB_ID=D525770
  • finagle-zipkin-core: Removed unused statsReceiver constructor argument from RawZipkinTracer. PHAB_ID=D527531


Breaking API Changes

  • finagle-core: Correct the spelling of Tracing.recordClientSendFrargmet() to Tracing.recordClientSendFragment() PHAB_ID=D505617
  • finagle-redis: Use StrictKeyCommand for XDEL PHAB_ID=D517291
  • finagle-toggle: Toggle.isDefinedAt(i: Int) has become Toggle.isDefined. Additionally, a new method Toggle.isUndefined has been added. PHAB_ID=D516868
  • finagle-zipkin-scribe: The scribe.thrift file was moved to finagle-thrift/src/main/thrift under a new namespace. com.twitter.finagle.thrift.scribe.(thrift|thriftscala) PHAB_ID=D511471

Bug Fixes

  • finagle-zipkin-scribe: The scribe client should be configured using the NullTracer. Otherwise, spans produced by the client stack will be sampled at initialSampleRate. PHAB_ID=D507318
  • finagle-redis: The redis client now includes the RedisTracingFilter and RedisLoggingFilter by default. Previously, the filters existed but were not applied to the client or accessible. PHAB_ID=D558552


Runtime Behavior Changes

  • finagle-core: FailFastFactory is now disabled at runtime when a client’s destination has only one endpoint, since the client cannot do anything meaningful by breaking the circuit early. This is recommended as a best practice anyway, now it’s the default behavior. Less things to configure and worry about! PHAB_ID=D498911
  • finagle-core: namer annotations are prefixed with “clnt/”. PHAB_ID=D492443
  • finagle-core: namer.success & namer.failure are not annotated as they are not request based. namer.tree annotation was also removed to reduce the size of traces.``PHAB_ID=D492443``
  • finagle-core: The offload filter client annotation is annotated under the child request span instead of its parent. The offload filter annotations are also changed to be binary annotations with the key (clnt|srv)/finagle.offload_pool_size and the value being the pool size PHAB_ID=D502521

Breaking API Changes

  • finagle-mux: The c.t.f.mux.transport.OpportunisticTlsConfig params were moved to c.t.f.ssl.OpportunisticTlsConfig. PHAB_ID=D482693
  • finagle-core: Migrated List[Tracer] to Seq[Tracer] in Tracing, and tracersCtx. PHAB_ID=D489697
  • finagle-core: PayloadSizeFilter and WireTracingFilter are now public APIs. PHAB_ID=D493803
  • finagle-zipkin-core: initialSampleRate flag will now fail if the sample rate is not in the range [0.0, 1.0]. PHAB_ID=D498408
  • finagle-mysql: mysql client annos are prefixed with clnt/ PHAB_ID=D492274

New Features

  • finagle-thrift: Expose c.t.f.thrift.exp.partitioning.PartitioningStrategy, the bundled PartitioningStrategy APIs are public for experiments. PHAB_ID=D503436
  • finagle-http: Add LoadBalancedHostFilter to allow setting host header after LoadBalancer PHAB_ID=D498954
  • finagle-core: Trace the request’s protocol identified by the ProtocolLibrary of the client stack. This is annotated under clnt/finagle.protocol. PHAB_ID=D495645
  • finagle-core: Add letTracers to allow setting multiple tracers onto the tracer stack. PHAB_ID=D489697
  • finagle-core: DeadlineFilter now exposes a metric admission_control/deadline/remaining_ms which tracks the remaining time in non-expired deadlines on the server side. An increase in this stat, assuming request latency is constant and timeout configurations upstream have not changed, may indicate that upstream services have become slower. PHAB_ID=D492608
  • finagle-redis: Make partitionedClient accessible. PHAB_ID=D492754
  • finagle-core, finagle-http, finagle-thriftmux: introduce MethodBuilder maxRetries configuration. A ThriftMux or HTTP method can now be configured to allow a specific number of maximum retries per request, where the retries are gated by the configured RetryBudget. This configuration can be applied via Http.client.methodBuilder(name).withMaxRetries(n) or ThriftMux.client.methodBuilder(name).withMaxRetries(n). PHAB_ID=D493139
  • finagle-memcached: Annotate the shard id of the backend the request will reach. PHAB_ID=D491738

Bug Fixes

  • finagle-zipkin-core: Remove flush and late-arrival annotations, which artificially extend trace durations. PHAB_ID=D498073
  • finagle-core: namer annotations are added at the Service level instead of ServiceFactory as traces are intended to be request based PHAB_ID=D492443

Runtime Behavior Changes

  • finagle-memcached: The key in RetrievalCommand are ommited in traces. The total number of Hits and Misses are annotated via a counter instead under clnt/memcached.(hits/misses) PHAB_ID=D491738


Runtime Behavior Changes

  • finagle: Bump jackson version to 2.11.0. PHAB_ID=D457496


New Features

  • finagle-redis: Add ConnectionInitCommand stack to set database and password. PHAB_ID=D468835
  • finagle-mysql: Add ConnectionInitSql stack to set connection init sql. PHAB_ID=D468856

Runtime Behavior Changes

  • finagle-core: Requeued reqeuests due to the c.t.finagle.service.RequeueFilter will generate their own spanId. PHAB_ID=D459106

Bug Fixes

  • finagle-core: Restrict OffloadFilter from allowing interruption of the work performed in the worker pool. This is to ensure that the worker thread isn’t interruptible, which is a behavior of certain FuturePool implementations. PHAB_ID=D465042 PHAB_ID=D465591
  • finagle-netty4: ChannelStatsHandler will now only count the first channel close(..) call when incrementing the closes counter. PHAB_ID=D462360

Breaking API Changes

  • finagle-toggle: Removed abstract type for c.t.finagle.Toggle, all Toggles are of type Int. This is to avoid Integer auto-boxing when calling Toggle.apply, thus to improve overall toggle performance. PHAB_ID=D456960
  • finagle-core: Retried requests due to the c.t.finagle.service.RetryFilter will generate their

own spanId. ``PHAB_ID=`D466083`

20.4.0 (DO NOT USE)

New Features

  • finagle-core: Add Transport.sslSessionInfo local context which provides access to the SSLSession, session id, cipher suite, and local and peer certificates. PHAB_ID=D459854
  • finagle-thrift/thriftmux: Thrift and ThriftMux client side can set a sharable TReusableBuffer by withTReusableBufferFactory. PHAB_ID=D452763
  • finagle: Server side TLS snooping has been added to all server implementations with the exception of Mux/ThriftMux. This feature allows a server to select between a cleartext and TLS connection based on identifying the initial bytes as a TLS record of type handshake. PHAB_ID=D436225

Breaking API Changes

  • finagle-partitioning: Rename c.t.finagle.partitioning.CacheNode and CacheNodeMetadata to c.t.finagle.partitioning.PartitionNode and PartitionNodeMetadata. PHAB_ID=D448015
  • finagle-partitioning: Rename c.t.finagle.partitioning.KetamaClientKey to HashNodeKey PHAB_ID=D449929

Bug Fixes

  • finagle-base-http: RequestBuilder headers use SortedMap to equalize keys in different caps. setHeader keys are case insensitive, the last one wins. PHAB_ID=D449255

Runtime Behavior Changes

  • finagle-stats: JsonExporter now caches the regex matching, so that you only need to check the result of regex matching on new stats. PHAB_ID=D459391


Runtime Behavior Changes

  • finagle-netty4: When not using the JDK implementation, the Netty reference counted SSL types are used which move SSL cleanup out of the GC cycle, reducing pause durations. PHAB_ID=D442409
  • finagle-netty4: Upgraded to Netty 4.1.47.Finale and netty-tcnative 2.0.29.Final. PHAB_ID=D444065

Bug Fixes

  • finagle-zipkin-scribe: add a logical retry mechanism to scribe’s TRY_LATER response PHAB_ID=D441366
  • finagle-zipkin-scribe: scope logical stats under “logical” PHAB_ID=D445075

Breaking API Changes

  • finagle-zipkin-scribe: update the deprecated FutureIface to MethodPerEndpoint PHAB_ID=D441366
  • finagle-core: Removed c.t.finagle.service.ShardingService. PHAB_ID=D445176


New Features

  • finagle-opencensus-tracing: Add support for providing a custom TextFormat for header propagation. PHAB_ID=D432003

Runtime Behavior Changes

  • finagle-base-http: Support for the SameSite cookie attribute is now on by default. This can be manipulated via the com.twitter.finagle.http.cookie.supportSameSiteCodec flag. This means that cookies that have a value other than Unset for the sameSite field will have the attribute encoded (by servers) and decoded (by clients). See this [Chromium blog post]( for more information about the SameSite attribute. PHAB_ID=D426349
  • finagle-core: The default NullTracer for ClientBuilder has been removed. Affected clients may now see tracing enabled by default via the Java ServiceLoader, as described in the [Finagle User’s Guide]( PHAB_ID=D437948
  • finagle-http2: The HTTP/2 frame logging tools now log at level INFO. This is symmetric with the behavior of the ChannelSnooper tooling which serves a similar purpose which is to aid in debugging data flow and isn’t intended to be enabled in production. PHAB_ID=D441876

Bug Fixes

  • finagle-http2: Initialize state in H2Pool before use in the gauge to avoid a NullPointerException. PHAB_ID=D428272
  • finagle-http2: HTTP/2 server pipeline now traps close calls to ensure that events from the initial HTTP/1.x pipeline don’t close the HTTP/2 session. For example, the initial pipeline was subject to session timeouts even though the tail of the socket pipeline was effectively dead. Closing of HTTP/2 server pipelines is now handled through the H2ServerFilter. PHAB_ID=D429554
  • finagle-http2: HTTP/2 servers clean out unused channel handlers when upgrading from a HTTP/1.x pipeline, removing some traps such as unintended timeouts. PHAB_ID=D429416
  • finagle-opencensus-tracing: Fixed internal server error when invalid or no propagation headers are provided. PHAB_ID=D432003
  • finagle-zipkin-scribe: export application metrics under a consistent zipkin-scribe scope. Finagle client stats under clnt/zipkin-scribe PHAB_ID=D432274

Breaking API Changes

  • finagle-zipkin-scribe: Coalesce ScribeRawZipkinTracer apply methods into two simple ones. PHAB_ID=D432274
  • finagle-zipkin-scribe: DefaultSampler moved to c.t.f.zipkin.core in finagle-zipkin-core. PHAB_ID=D439456
  • finagle-zipkin-scribe: initialSampleRate GlobalFlag is moved to finagle-zipkin-core, under the same package scope c.t.f.zipkin. PHAB_ID=D439456


New Features

  • finagle-memcached: Upgrade to Bijection 0.9.7. PHAB_ID=D426488
  • finagle-opencensus-tracing: Enables cross-build for 2.13.0. PHAB_ID=D421452
  • finagle-thriftmux: Add support for automatically negotiating compression between a client and server. Off by default, clients and servers must be configured to negotiate. PHAB_ID=D414638
  • finagle-stats: Enables cross-build for 2.13.0. PHAB_ID=D421449
  • finagle-stats-core: Enables cross-build for 2.13.0. PHAB_ID=D421449
  • finagle-serversets: Add generic metadata support in ServerSet. Add support for announcing the generic metadata via ZkAnnouncer. Add support to resolve the generic metadata via Zk2Resolver PHAB_ID=D421151
  • finagle-serversets: Add support for announcing additional endpoints via ZkAnnouncer PHAB_ID=D431062

Breaking API Changes

  • finagle-partitioning: ZKMetadata case class has a new default argument breaking API for Java users. PHAB_ID=D421151
  • finagle-serversets: Endpoint case class has a new metadata argument. PHAB_ID=D421151

Bug Fixes

  • finagle-memcached: MemcachedTracingFilter should replace StackClient.Role.protoTracing and not the protocol-agnostic ClientTracingFilter PHAB=D427660


New Features

  • finagle-core, finagle-exp: Add annotations to DarkTrafficFilter to identify which span is dark, as well as which light span it correlates with. PHAB_ID=D402864
  • finagle-core: Introduce Trace#traceLocal for creating local spans within a trace context. PHAB_ID=D404869

Runtime Behavior Changes

  • finagle: Upgrade to jackson 2.9.10 and jackson-databind PHAB_ID=D410846
  • finagle-core: Per-method metrics on MethodBuilder are now created lazily, so if you have methods that you don’t use, the associated metrics won’t be exported. PHAB_ID=D400382
  • finagle-mysql: The RollbackFactory no longer attempts to roll back if the underlying session is closed since it is highly unlikely to succeed. It now simply poisons the session and calls close. PHAB_ID=D408155
  • finagle-netty4: Change the ‘connection_requests’ metric to debug verbosity. PHAB_ID=D391289
  • finagle-serversets: Ensure ZkSession#retrying is resilient to ZK host resolution failure. PHAB_ID=D403895
  • finagle-thrift: Per-method metrics are now created lazily, so if you have methods on a Thrift service that you don’t use, the associated metrics won’t be exported. PHAB_ID=D400382
  • finagle-zipkin-core: Tracing produces microsecond resolution timestamps in JDK9 or later. PHAB_ID=D400661
  • finagle-core: Trace#time and Trace#timeFuture no longer generate timestamped annotations or silently discard timing information. They now instead generate a BinaryAnnotation containing the timing information. In order to also get timestamped Annotations for when the operation began and ended, use in conjunction with Trace#traceLocal. PHAB_ID=D404869

Breaking API Changes

  • finagle-core: The RetryPolicy companion object is no longer a JavaSingleton. PHAB_ID=D399947
  • finagle-thrift: The RichClientParam constructors are now all either deprecated, so to construct it, you must call one of the RichClientParam.apply methods. PHAB_ID=D400382


  • finagle-core: Deprecate Tracing#record(message, duration) as it does not have the intended effect and silently discards any duration information in the resulting trace. Instead you should use either Tracing#recordBinary or a combination of Trace#traceLocal and Trace#time. PHAB_ID=D404869

Bug Fixes

  • finagle-core: ClosableService client stack module that prevents the reuse of closed services when FactoryToService is not set. This is important for clients making use of the newClient api. PHAB_ID=D407805


New Features

  • finagle-base-http: The Uri class now provides access publicly to its path, which is the request uri without the query parameters. PHAB_ID=D393893
  • finagle-mysql: Adding native support to finagle-mysql for MySQL JSON Data Type. A client can now use jsonAsObjectOrNull[T] or getJsonAsObject[T] APIs on c.t.f.mysql.Row to read the underlying json value as type T or use jsonBytesOrNull API to get a raw byte array of the the json column value. PHAB_ID=D390914
  • finagle-mysql: MySQL integration tests can now run on a port other than the default (3306). Add a port property to .finagle-mysql/ to customize the value. PHAB_ID=D390914

Runtime Behavior Changes

  • finagle: Upgrade to Netty 4.1.43.Final and netty-tcnative 2.0.26.Final. PHAB_ID=D389870
  • finagle: Add initial support for JDK 11 compatibility. PHAB_ID=D365075
  • finagle: Upgrade to caffeine 2.8.0 PHAB_ID=D384592
  • finagle-http2: Nacks in the form of RST(STREAM_REFUSED | ENHANCE_YOUR_CALM) no longer surface as a RstException, instead opting for a generic Failure to be symmetric with the HTTP/1.x nack behavior. PHAB_ID=D389234
  • finagle-mux: The mux handshake latency stat has be changed to Debug verbosity. PHAB_ID=D393158
  • finagle-serversets: finagle/serverset2/stabilizer/notify_ms histogram has been downgraded to debug verbosity. PHAB_ID=D392265

Breaking API Changes

  • finagle-base-http: c.t.f.http.codec.HttpContext moved into c.t.f.http.codec.context.HttpContext PHAB_ID=D380407


New Features

  • finagle-partition: Enables cross-build for 2.13.0. PHAB_ID=D380444
  • finagle-exception: Enables cross-build for 2.13.0. PHAB_ID=D381107
  • finagle-exp: Enables cross-build for 2.13.0. PHAB_ID=D380497
  • finagle-http: Expose header validation API to public. PHAB_ID=D381771
  • finagle-mysql: Enables cross-build for 2.13.0. PHAB_ID=D377721
  • finagle-{mux,thrift,thrift-mux}: Enables cross-build for 2.13.0. PHAB_ID=D373165
  • finagle-netty4: Add support to stop default Finagle Netty 4 Timer. PHAB_ID=D381605
  • finagle-redis: Enables cross-build for 2.13.0. PHAB_ID=D381107
  • finagle-tunable: Enables cross-build for 2.13.0. PHAB_ID=D373170
  • finagle-grpc-context: Enables cross-build for 2.13.0. PHAB_ID=D373168
  • finagle-thrift: Pass a factory to create a TReusableBuffer as the parameter of a finagle client to allow multiple clients share one TReusableBuffer. PHAB_ID=D378466
  • finagle-zipkin-{core,scribe}: Enables cross-build for 2.13.0. PHAB_ID=D381675

Runtime Behavior Changes

  • finagle-base-http: Better performance for the default HeaderMap.add method for headers with the same name. PHAB_ID=D381142
  • finagle-http2: H2ServerFilter will no longer swallow exceptions that fire via exceptionCaught in the Netty pipeline. PHAB_ID=D369185
  • finagle-http: Remove legacy HTTP/2 client implementation and make the MultiplexHandler-based implementation the default HTTP/2. PHAB_ID=D362950

Breaking API Changes

  • finagle-core: c.t.f.l.FailureAccrualFactory’s didMarkDead() changed to didMarkDead(Duration). The Duration is the length of time the endpoint is marked dead. PHAB_ID=D369209
  • finagle-core: removed the staticDetermisticApertureWidth flag. The behavior is now as if the flag was set to true which was also the default behavior. PHAB_ID=D382779

Bug Fixes

  • finagle-mux: Mux now properly propagates Ignorable failures multiple levels for superseded backup requests. This allows for more accurate success rate metrics for downstream services, when using backup requests. PHAB_ID=D365729


New Features

  • finagle-{core,init,toggle,netty4}: Enables cross-build for 2.13.0. PHAB_ID=D364013
  • finagle-base-http: Add None as a valid SameSite header value. PHAB_ID=D365170

Breaking API Changes

  • finagle-core: The constructor on c.t.f.filter.NackAdmissionFilter used for testing that took an Ema.Monotime has been removed. PHAB_ID=D351249

  • finagle-core: The Adddress.ServiceFactory variant has been promoted from experimental status and moved to be properly part of c.t.f.Address. PHAB_ID=D357122

  • finagle-http: improve performance of c.t.f.http.filter.StatsFilter. This results in two notable API changes:

    1. There is a private[filter] constructor which can take a () => Long for determining the current time in milliseconds (the existing StatsFilter(StatsReceiver) constructor defaults to using Stopwatch.systemMillis for determining the current time in milliseconds.
    2. The protected count(Duration, Response) method has been changed to private[this] count(Long, Response) and is no longer part of the public API.


  • finagle-partitioning: the hash-based routing that memcached uses has been relocated to a new top-level module so that it can be used more broadly across protocols. This results in several classes moving to the c.t.f.partitioning package:

    1. The Memcached.param.EjectFailedHost, KeyHasher, and NumReps parameters are now available under c.t.f.partitioning.param
    2. The FailureAccrualException and CacheNode definitions are now in the c.t.f.paritioning package.
    3. The ZkMetadata class has moved to c.t.f.p.zk and the finagle-serverset module now depends on finagle-partitioning.


Runtime Behavior Changes

  • finagle-http: c.t.f.http.service.NotFoundService has been changed to no longer use Request.response. Use of Request.response is deprecated and discouraged. PHAB_ID=D357348
  • finagle-mysql: Handshaking for the MySQL ‘Connection Phase’ now occurs as part of session acquisition. As part of this change, the com.twitter.finagle.mysql.IncludeHandshakeInServiceAcquisition toggle has been removed and it no longer applies. PHAB_ID=D355549
  • finagle: Upgrade to Netty 4.1.39.Final. PHAB_ID=D355848
  • finagle-http: Enable Ping Failure Detection for MultiplexHandler based HTTP/2 clients. Note that the Ping Failure Detection implementation has been removed completely from the non-MultiplexHandler based HTTP/2 client. PHAB_ID=D360712
  • finagle: Added a dependency on Scala Collections Compat 2.1.2. PHAB_ID=D364013

Bug Fixes

  • finagle-base-http: Removes the Cookie header of a c.t.f.http.Message whenever its cookie map becomes empty. PHAB_ID=D361326


Breaking API Changes

  • finagle-core: The contents of the c.t.f.dispatch.GenSerialClientDispatcher object have been moved to the new c.t.f.dispatch.ClientDispatcher object. The stats receiver free constructors of GenSerialClientDispatcher and SerialClientDispatcher have been removed. PHAB_ID=D342883
  • finagle-thrift: The deprecated ReqRepThriftServiceBuilder object has been removed. Users should migrate to ReqRepMethodPerEndpointBuilder. PHAB_ID=D345740

Runtime Behavior Changes

  • finagle-core: Failed reads on Linux due to a remote peer disconnecting should now be properly seen as c.t.f.ChannelClosedException instead of a c.t.f.UnknownChannelException. PHAB_ID=D336428
  • finagle: Upgrade to Jackson 2.9.9. PHAB_ID=D345969
  • finagle: Upgrade to Netty 4.1.38.Final. PHAB_ID=D346259
  • finagle-base-http: Moved c.t.f.http.serverErrorsAsFailures out of its package object, which changes its name from com.twitter.finagle.http.package$serverErrorsAsFailures to com.twitter.finagle.http.serverErrorsAsFailures. PHAB_ID=D353045
  • finagle-thrift: Moved c.t.f.thrift.maxReusableBufferSize out of its package object, which changes its name from com.twitter.finagle.thrift.package$maxReusableBufferSize to com.twitter.finagle.thrift.maxReusableBufferSize. PHAB_ID=D353045


New Features

  • finagle-http: Measure streaming (message.isChunked) chunk payload size with two new histograms: stream/request/chunk_payload_bytes and stream/response/chunk_payload_bytes, they are published with a debug verbosity level. These chunk payload sizes are also traced via the same trace keys. PHAB_ID=D337877
  • finagle-base-http: Add support for new “b3” tracing header. PHAB_ID=D334419
  • finagle-core: Allow to not bypass SOCKS proxy for localhost by using the GlobalFlag -com.twitter.finagle.socks.socksProxyForLocalhost PHAB_ID=D337073
  • finagle-core: OffloadFilter flag to reduce network contention. PHAB_ID=D331502
  • finagle-exp: Add private c.t.f.exp.ConcurrencyLimitFilter for rejecting requests that exceed estimated concurrency limit PHAB_ID=D328815

Runtime Behavior Changes

  • finagle-http: c.t.f.http.Cors has been changed to no longer use the c.t.f.http.Response associated with the passed in c.t.f.http.Request. PHAB_ID=D332765
  • finagle-http: c.t.f.http.filter.ExceptionFilter has been changed to no longer use the c.t.f.http.Response associated with the passed in c.t.f.http.Request. PHAB_ID=D333509
  • finagle-http: Optimize creation of new Http Dispatchers by re-using created metrics and loggers. PHAB_ID=D335114

Breaking API Changes

  • finagle-base-http: Removed the methods setStatusCode and getStatusCode from c.t.f.http.Response which have been deprecated since 2017. PHAB_ID=D326326
  • finagle-core: All deprecated c.t.f.builder.ServerBuilder#build methods have been removed. Users should migrate to using the build method which takes a ServiceFactory[Req, Rep] as a parameter. PHAB_ID=D331011
  • finagle-core: The c.t.f.ssl.client.SslClientEngineFactory#getHostname method has been removed. All uses should be changed to use the getHostString method of SslClientEngineFactory instead. PHAB_ID=DD334087
  • finagle-http: The setOriginAndCredentials, setMaxAge, setMethod, and setHeaders methods of c.t.f.http.Cors.HttpFilter are no longer overridable. PHAB_ID=D332765
  • finagle-http: The details of the c.t.f.Http.HttpImpl class are meant to be implementation details so the class constructor was made private along with the fields. Along these same lines the c.t.f.Http.H2ClientImpl.transporter method has been moved to a private location. PHAB_ID=D337136

Bug Fixes

  • finagle-core: Ensure ClientDispatcher queueSize gauge is removed on transport close, instead of waiting for clean-up at GC time. PHAB_ID=D331923
  • finagle-http2: Don’t propagate stream dependency information for the H2 client. PHAB_ID=D332191


New Features

  • finagle-core: SSL/TLS session information has been added to c.t.f.ClientConnection. PHAB_ID=D323305
  • finagle-core: Add a Stack Module with 7 parameters for convenience sake. PHAB_ID=D325382
  • finagle-core: For both, servers and clients, introduce a way to shift application-level future callbacks off of IO threads, into a given FuturePool or ExecutorService. Use withExecutionOffloaded configuration method (on a client or a server) to access new functionality. PHAB_ID=D325049
  • finagle-http: Added counters for request/response stream as: stream/request/closed, stream/request/failures, stream/request/failures/<exception_name>, stream/request/opened, stream/request/pending and stream/response/closed, stream/response/failures, stream/response/failures/<exception_name>, stream/response/opened, stream/response/pending. The counters will be populated when isChunked is set to true, the failures counters will be populated when isChunked is set to true and the stream fails before it has been fully read in the request and response respectively. PHAB_ID=D315041
  • finagle-http: Add two new API variants in CookieMap: addAll and removeAll that allow for adding and removing cookies in bulk, without triggering a header rewrite on each item. PHAB_ID=D318013
  • finagle-mysql: finagle-mysql now supports using SSL/TLS with MySQL. SSL/TLS can be turned on by calling withTransport.tls(sslClientConfiguration) with a specified c.t.f.ssl.client.SslClientConfiguration. PHAB_ID=D328077

Runtime Behavior Changes

  • finagle: Upgrade to Netty 4.1.35.Final and netty-tcnative 2.0.25.Final. PHAB_ID=D312439
  • finagle-core: The default failure accrual policy has been changed from one which uses only consecutive failures to a hybrid model which uses both success rate over a window and consecutive failures. Previously this was changeable via toggle. The toggle has been removed, and the hybrid version has been made the default. PHAB_ID=D327394
  • finagle-http: Rename request_stream_duration_ms to stream/request/duration_ms and response_stream_duration_ms to stream/response/duration_ms. The stats will be populated when isChunked is set to true in the request and response respectively. PHAB_ID=D315041
  • finagle-http2: Disable ping-based failure detector in HTTP/2 client as it seems to do more harm than good. PHAB_ID=D322357
  • finagle-http2: Frame logging is now disabled by default for clients. To enable, use the c.t.f.http2.param.FrameLogging.Enabled Stack Param. For example: Http.client.configured(FrameLogging.Enabled). PHAB_ID=D326727
  • finagle-netty4: When using a Netty LocalChannel, the value of the BackPressure stack param is effectively changed to backPressureDisabled so that other functionality (e.g. SSL/TLS) works as expected. PHAB_ID=D319011
  • finagle-netty4: finagle/netty/pooling/used now includes the size of the buffers in the thread-local caches. PHAB_ID=D320021
  • finagle-core: Stats and retry modules use a ResponseClassifier to give hints for how to handle failure (e.g., Is this a success or is it a failure? If it’s a failure, may I retry the request?). The stats module increments a success counter for successes, and increments a failure counter for failures. But there isn’t a way to tell the stats module to just do nothing. And, this is exactly what the stats module should do (nothing) in the case of ignorable failures (e.g. backup request cancellations). To represent these cases, we introduce a new ResponseClass: Ignorable. PHAB_ID=D316884

Bug Fixes

  • finagle-core: UsingSslSessionInfo would fail to be constructed properly when SSLSession.getLocalCertificates returns ‘null’. PHAB_ID=D324499
  • finagle-http: Finagle now properly sets the Transport.peerCertificate local context when using HTTP/2. PHAB_ID=D324392
  • finagle-http: c.t.f.http.collection.RecordSchema.Record is now thread-safe. PHAB_ID=D325700
  • finagle-zipkin-core: Fix a race condition which could cause a span to get logged missing some annotations. PHAB_ID=D319367
  • finagle-mysql: Don’t log c.t.f.ChannelClosedException when rolling back a transaction fails. PHAB_ID=D327111

Breaking API Changes

  • finagle-core: The exceptions c.t.f.SslHandshakeException and c.t.f.SslHostVerificationException were no longer used and have been removed. PHAB_ID=D330138
  • finagle-mysql: The structure of c.t.f.mysql.Request has changed. It is now based on a higher level c.t.f.mysql.ProtocolMessage and the cmd field must contain a value. Additionally, the synthetic Command.COM_NO_OP has been removed, as due to the restructuring it was no longer necessary. PHAB_ID=D327554
  • finagle-mysql: Uses of the abbreivation ‘cap’ have been renamed to the full word: ‘capabilities’, including for the baseCapabilities of Capability. PHAB_ID=D329603


  • finagle-http: Removed deprecated response_size in Finagle Http stats. This is a duplicate stat of response_payload_bytes. PHAB_ID=D328254``


No Changes


New Features

  • finagle-http: Add two new methods to com.twitter.finagle.http.MediaType, MediaType#typeEquals for checking if two media types have the same type and subtype, ignoring their charset, and MediaType#addUtf8Charset for easily setting a utf-8 charset. PHAB_ID=D308761

Bug Fixes

  • finagle-http: Ensure server returns 400 Bad Request when non-ASCII characters are present in the HTTP request URI path. PHAB_ID=D312009

Runtime Behavior Changes

  • finagle-core: Deterministic aperture (d-aperture) load balancers no longer export “loadband” scoped metrics: “widen”, “narrow”, “offered_load_ema”. These were not necessary as d-aperture does not change the aperture size at runtime. PHAB_ID=D303833
  • finagle-core: Request logging now defaults to disabled. Enable it by configuring the RequestLogger Stack parameter on your Client or Server. PHAB_ID=D308476
  • finagle-core: Subtree binding failures in NameTree.Union’s are ignored in the final binding result. PHAB_ID=D315282

Breaking API Changes

  • finagle-core: The c.t.f.client.EndpointerModule and c.t.f.pushsession.PushStackClient public and protected APIs have been changed to use the abstract instead of the concrete as relying on the concrete implementation was not necessary. PHAB_ID=D315111
  • finagle-http: For Finagle HTTP clients, the withMaxRequestSize(size) API method has been removed. For Finagle HTTP servers, the withMaxResponseSize(size) method has been removed. The underlying Stack params which are set by these methods are respectively HTTP server and HTTP client side params only. Using these removed methods had no effect on the setup of Finagle HTTP clients and servers. PHAB_ID=D314019
  • finagle-mysql: HandshakeResponse has been removed from finagle-mysql’s public API. It is expected that users of the library are relying entirely on finagle-mysql for handshaking. PHAB_ID=D304512


New Features

  • finagle-core: Make maxDepth in Namer configurable. PHAB_ID=D286444

    • namerMaxDepth in Namer now configurable through a global flag (namerMaxDepth)
  • finagle-core: The newly renamed SslSessionInfo is now public. It is intended for providing information about a connection’s SSL/TLS session. PHAB_ID=D286242

  • finagle-core: Added the c.t.finagle.DtabFlags trait which defines a Flag and function for appending to the “base” c.t.finagle.Dtab delegation table. PHAB_ID=D297596

  • finagle-http: Finagle HTTP implementation now supports trailing headers (trailers). Use c.t.f.http.Message.trailers to access trailing headers on a fully-buffered message (isChunked == false) or c.t.f.http.Message.chunkReader on a message with chunked payload (isChunked == true). PHAB_ID=D283999

  • finagle-http,thriftmux: Added tracing annotations to backup requests. PHAB_ID=D285486

    • Binary annotation “srv/backup_request_processing”, when servers are processing backup requests.
  • finagle-http: Added new server metrics to keep track of inbound requests that are rejected due to their headers containing invalid characters (as seen by RFC-7230): rejected_invalid_header_names and rejected_invalid_header_values. PHAB_ID=D294754

  • finagle-http: Added stats of the duration in milliseconds of request/response streams: request_stream_duration_ms and response_stream_duration_ms. They are enabled by using .withHttpStats on Http.Client and Http.Server PHAB_ID=D297900

  • finagle-mysql: A new toggle, “com.twitter.finagle.mysql.IncludeHandshakeInServiceAcquisition”, has been added. Turning on this toggle will move MySQL session establishment (connection phase) to be part of service acqusition. PHAB_ID=D301456

  • finagle-core: Support for MethodBuilder and stack construction outside of c.t.f package. PHAB_ID=D275053. This includes: - c.t.f.client.MethodBuilder is now public. - construction of the following stack modules are now public: c.t.f.factory.TimeoutFactory,

    c.t.f.filter.ExceptionSourceFilter, c.t.f.loadbalancer.LoadBalancerFactory, c.t.f.service.Retries

Runtime Behavior Changes

  • finagle-core: Client-side nacking admission control now defaults on. See the documentation on c.t.f.filter.NackAdmissionFilter for details. This can be disabled by setting the global flag, com.twitter.finagle.client.useNackAdmissionFilter, to false. PHAB_ID=D289583
  • finagle-core: LatencyCompensation now applies to service acquisition. PHAB_ID=D285574
  • finagle-http: HTTP headers validation on the outbound path is now in compliance with RFC7230. PHAB_ID=D247125
  • finagle-netty4: Netty’s reference leak tracking now defaults to disabled. Set the flag com.twitter.finagle.netty4.trackReferenceLeaks to true to enable. PHAB_ID=D297031

Breaking API Changes

  • finagle: Dropped a dependency on Netty 3:
  • finagle-netty3 sub-project has been removed
  • finagle-http-cookie sub-project has been removed
  • c.t.f.http.Cookie no longer takes Netty’s DefaultCookie in the constructor


  • finagle-core: The peerCertificate methods of c.t.f.t.TransportContext and c.t.f.p.PushChannelHandle have been replaced with the more robust sslSessionInfo. Users looking for just the functional equivalence of peerCertificate can use sslSessionInfo.peerCertificates.headOption. PHAB_ID=D285926
  • finagle-core: The com.twitter.finagle.core.UseClientNackAdmissionFilter toggle has been replaced by a global flag, com.twitter.finagle.client.useNackAdmissionFilter. PHAB_ID=D289583
  • finagle-thrift: Allow users to specify stringLengthLimit and containerLengthLimit PHAB_ID=D286346 - method parameter readLength in com.twitter.finagle.thrift.Protocols#binaryFactory renamed to stringLengthLimit to reflect usage - method parameter containerLengthLimit added to com.twitter.finagle.thrift.Protocols#binaryFactory


New Features

  • finagle-core: Added tracing annotations to backup requests. PHAB_ID=D280998
    • Timestamped annotation “Client Backup Request Issued”
    • Timestamped annotation “Client Backup Request Won” or “Client Backup Request Lost”
    • Binary annotation “clnt/backup_request_threshold_ms”, with the current value of the latency threshold, in milliseconds
    • Binary annotation “clnt/backup_request_span_id”, with the span id of the backup request

Breaking API Changes

  • finagle-core: Deprecated multi-param legacy tls methods have been removed in c.t.f.param.ServerTransportParams and c.t.f.builder.ServerBuilder. Users should migrate to using the tls(SslServerConfiguration) method instead. PHAB_ID=D277045

Runtime Behavior Changes

  • finagle-core: The tracing annotations from MkJvmFilter have been enhanced. PHAB_ID=D282590
    • Timestamped annotations “GC Start” and “GC End” for each garbage collection event that occurred during the request.
    • Binary annotation “jvm/gc_count”, with the total number of garbage collection events that occurred during the request.
    • Binary annotation “jvm/gc_ms”, with the total milliseconds of garbage collection events that occurred during the request.


New Features

  • finagle-core: Added gauge is_marked_dead as an indicator of whether the host is marked as dead(1) or not(0) in FailFastFactory. PHAB_ID=D263552
  • finagle-core: KeyCredentials.CertsAndKey has been added as an option for c.t.f.ssl.KeyCredentials for when the certificate and certificate chain are contained within the same file. PHAB_ID=D264325
  • finagle-thriftmux: Additional information is now annotated in traces for clients using Scrooge generated Thrift bindings. PHAB_ID=D269383, PHAB_ID=D270597, PHAB_ID=D272934. This includes:
    • RPC method name
    • Request serialization time, in nanoseconds
    • Request deserialization time, in nanoseconds
    • Response serialization time, in nanoseconds
    • Response deserialization time, in nanoseconds

Breaking API Changes

  • finagle-http: Removed Http.Client.withCompressionLevel because it wasn’t doing anything. To migrate your client, simply remove the configuration–it had absolutely no effect. PHAB_ID=D260077

  • finagle-http: c.t.f.dispatch.ExpiringServerDispatcher was dead code. We removed it. PHAB_ID=D269331

  • finagle-thrift: Removed newIface and newServiceIface methods from c.t.f.thrift.ThriftRichClient.MultiplexedThriftClient, which are deprecated in November 2017. PHAB_ID=D271774

  • finagle-thrift: Removed deprecated APIs located in Thrift.scala: PHAB_ID=D272811

    1. c.t.f.Thrift.Client.stats => use c.t.f.Thrift.Client.clientParam.clientStats
    2. c.t.f.Thrift.withProtocolFactory => use c.t.f.Thrift.client.withProtocolFactory
    3. c.t.f.Thrift.withClientId => use c.t.f.Thrift.client.withClientId
    4. c.t.f.Thrift.Server.serverLabel => use c.t.f.Thrift.Server.serverParam.serviceName
    5. c.t.f.Thrift.Server.serverStats => use c.t.f.Thrift.Server.serverParam.serverStats
    6. c.t.f.Thrift.Server.maxThriftBufferSize => use c.t.f.Thrift.Server.serverParam.maxThriftBufferSize
  • finagle-thrift: c.t.f.thrift.ThriftServiceIface.Filterable is removed, use c.t.f.thrift.service.Filterable instead. PHAB_ID=D272427

  • finagle-thrift: c.t.f.thrift.ThriftServiceIface is removed, use c.t.f.thrift.service.ThriftServicePerEndpoint instead. PHAB_ID=D272427

  • finagle-thriftmux: Removed deprecated APIs located in ThriftMux.scala: PHAB_ID=D272811

    1. c.t.f.ThriftMux.Client.stats => use c.t.f.ThriftMux.Clien.clientParam.clientStats
    2. c.t.f.ThriftMux.Server.serverLabel => use c.t.f.ThriftMux.Server.serverParam.serviceName
    3. c.t.f.ThriftMux.Server.serverStats => use c.t.f.ThriftMux.Server.serverParam.serverStats
    4. c.t.f.ThriftMux.Server.maxThriftBufferSize => use c.t.f.ThriftMux.Server.serverParam.maxThriftBufferSize
  • finagle-thriftmux: ThriftMux.Client.pushMuxer is removed. Use ThriftMux.Client.standardMuxer instead. PHAB_ID=D269373

  • finagle-thriftmux: ThriftMux.serverMuxer is removed. Use ThriftMux.Server.defaultMuxer instead. PHAB_ID=D269373

  • finagle-base-http: Removed the c.t.f.http.Statuses java helper, which was deprecated two years ago in favor of using c.t.f.http.Status directly. PHAB_ID=D269224

  • finagle-base-http: Removed the c.t.f.http.Versions java helper, which was deprecated two years ago in favor of using c.t.f.http.Version directly. PHAB_ID=D269207

  • finagle-base-http: Removed the c.t.f.http.Methods java helper, which was deprecated two years ago in favor of using c.t.f.http.Method directly. PHAB_ID=D273235

  • finagle-http: c.t.f.http.Response.Ok was removed. Use just Response() or Response.Proxy if you need to mock it. PHAB_ID=D269737

  • finagle-core: Drv.Aliased and Drv.newVose are now private, please construct a Drv instance using Drv.apply or Drv.fromWeights. PHAB_ID=D262960

  • finagle-core: c.t.f.BackupRequestLost is now removed. Please use c.t.f.Failure.ignorable instead. PHAB_ID=D270833

Bug Fixes

  • finagle-http: Fix for a bug where HTTP/2 clients could retry requests that had a chunked body even if the request body was consumed. PHAB_ID=D258719
  • finagle-http: Fix for a bug where HTTP clients could assume connections are reusable, despite having streaming requests in flight. PHAB_ID=D264985

Runtime Behavior Changes

  • finagle-core: Faster Filters. Removes unnecessary Service.rescue proxies from the intermediate andThen-ed Filters. Previously in rare cases you might have seen a raw Exception not wrapped in a Future if the Filter threw. These will now consistently be lifted into a Future.exception. PHAB_ID=D269003
  • finagle-core: MethodBuilder metrics filtering updated to now report rolled-up logical failures. PHAB_ID=D271195
  • finagle-http: Disabling Netty3 cookies in favor of Netty4 cookies. PHAB_ID=D262776
  • finagle-http: Removed the debug metrics http/cookie/dropped_samesites and http/cookie/flagless_samesites. PHAB_ID=D267239


  • finagle-core: Multi-param legacy tls methods have been deprecated in c.t.f.param.ServerTransportParams and c.t.f.builder.ServerBuilder. Users should migrate to using the tls(SslServerConfiguration) method instead. PHAB_ID=D265844
  • finagle-core: $client.withSession.maxIdleTime is now deprecated; use $client.withSessionPool.ttl instead to set the maximum allowed duration a connection may be cached for. PHAB_ID=D272370
  • finagle-serversets: c.t.f.zookeeper.ZkResolver has been deprecated in favor of c.t.f.serverset2.Zk2Resolver. PHAB_ID=D273608


New Features

  • finagle-core: c.t.f.s.StackBasedServer has been changed to extend the c.t.f.Stack.Transformable trait. This brings StackBasedServer into parity with c.t.f.c.StackBasedClient, which already extends the Stack.Transformable trait. PHAB_ID=D253542
  • finagle-http: HttpMuxer propagates the close signal to the underlying handlers. PHAB_ID=D254656
  • finagle-stats-core: introduce flag to allow logging metrics on service shutdown. PHAB_ID=D253590

Breaking API Changes

  • finagle-core: The deprecated c.t.f.b.ServerBuilder.stack method which takes a function has been removed. Uses of this method should be changed to use the c.t.f.b.ServerBuilder.stack method which takes a c.t.f.s.StackBasedServer instead. PHAB_ID=D251975
  • finagle-core: The type of c.t.f.b.ServerConfig.nilServer has been changed from Server[Req, Rep] to StackBasedServer[Req, Rep]. PHAB_ID=D252142
  • finagle-core: The access level of the c.t.f.b.ServerBuilder.copy method has changed from protected to private. PHAB_ID=D252142
  • finagle-core: The bridge type c.t.f.b.Server has been removed. Users should change to use c.t.f.ListeningServer instead. Uses of the previously deprecated Server.localAddress should use ListeningServer.boundAddress instead. PHAB_ID=D254339
  • finagle-core: The deprecated c.t.f.t.Transport.localAddress and c.t.f.t.Transport.remoteAddress methods are now final and can no longer be extended. Users should migrate to the respective c.t.f.t.TransportContext methods. PHAB_ID=D256257
  • finagle-thrift: The c.t.f.t.ThriftRichClient.protocolFactory and c.t.f.t.ThriftRichServer.protocolFactory methods have been removed. Users should switch to using ThriftRichClient.clientParam.protocolFactory and ThriftRichServer.serverParam.protocolFactory instead. In addition, implementations of the protocolFactory method have been removed from the concrete c.t.f.Thrift and c.t.f.ThriftMux client and server. PHAB_ID=D256217

Bug Fixes

  • finagle-core: Failed writes on Linux due to a remote peer disconnecting should now be properly seen as a c.t.f.ChannelClosedException instead of a c.t.f.UnknownChannelException. PHAB_ID=D256007
  • finagle-http: Compression level of 0 was failing on the server-side when speaking h2c. Updated so that it can handle a request properly. PHAB_ID=D251320
  • finagle-thriftmux: A Java compatibility issue for users trying to call withOpportunisticTls on ThriftMux clients and servers has been fixed. PHAB_ID=D256027

Runtime Behavior Changes

  • finagle-core: ServiceFactory.const propagates the close from the ServiceFactory to the underlying service, instead of ignoring it. PHAB_ID=D254656


New Features

  • finagle-redis: Add support for the new stream API released in Redis 5.0. PHAB_ID=D244329
  • finagle-core: Add Java compatibility for c.t.f.Filter.TypeAgnostic.Identity via c.t.f.Filter.typeAgnosticIdentity(). PHAB_ID=D242006
  • finagle-core: Add Java compatibility for c.t.f.Name through Names. PHAB_ID=D242084
  • finagle-core: Introduce a StackServer.withStack overload that makes modifying the existing Stack easier when using method chaining. PHAB_ID=D246893
  • finagle-stats: Split the implementation and ServiceLoading into separate modules. The implementation is in finagle-stats-core. This is backwards compatible for existing users of finagle-stats while allowing new usages built on top. PHAB_ID=D249875
  • finagle-thrift: Add c.t.finagle.thrift.MethodMetadata which provides a LocalContext Key for setting information about the current Thrift method and an accessor for retrieving the currently set value. PHAB_ID=D241295
  • finagle-thrift: Update c.t.finagle.thrift.MethodMetadata to provide an asCurrent method to set the current c.t.finagle.thrift.MethodMetadata in the LocalContext. PHAB_ID=D243625

Breaking API Changes

  • finagle-core: The c.t.u.Closable trait has been removed from c.t.f.t.TransportContext, as well as the close and onclose methods. Uses of these methods within TransportContext should be changed to use the corresponding methods on c.t.f.t.Transport instead. PHAB_ID=D244742
  • finagle-core: The deprecated c.t.f.t.Transport.peerCertificate method on the Transport class (not the Transport.peerCertificate Finagle context) has been removed. Uses of this method should be changed to use c.t.f.t.TransportContext.peerCertificate instead. PHAB_ID=D250027
  • finagle-core: The deprecated c.t.f.t.TransportContext.status method has been removed from TransportContext. Uses of this method should be changed to use c.t.f.t.Transport.status instead. PHAB_ID=D247234
  • finagle-mysql: c.t.f.m.Charset has been renamed to c.t.f.m.MysqlCharset to resolve any ambiguity between it and the Charset Stack parameter. PHAB_ID=D240965
  • finagle-mysql: All Stack params (Charset, Credentials, Database, FoundRows, MaxConcurrentPrepareStatements, UnsignedColumns) have been moved to the com.twitter.finagle.mysql.param namespace. PHAB_ID=D242473
  • finagle-mysql: The deprecated c.t.f.m.Client.apply(factory, statsReceiver) method has been removed. PHAB_ID=D243038
  • finagle-mysql: The c.t.f.m.Handshake class and companion object have been made private. PHAB_ID=D244734
  • finagle-http: Rename the toggle ‘c.t.f.h.UseH2CClients’ to ‘c.t.f.h.UseH2CClients2’. PHAB_ID=D247320

Runtime Behavior Changes

  • finagle: Upgrade to Netty 4.1.31.Final and netty-tcnative 2.0.19.Final. PHAB_ID=D235402
  • finagle-base-http: The DefaultHeaderMap will replace obs-fold ( CRLF 1*(SP/HTAB) ) in inserted header values. PHAB_ID=D245928
  • finagle-core: MethodBuilder#idempotent and MethodBuilder#nonIdempotent will no longer clobber MethodBuilder.withRetries.withClassifier. PHAB_ID=D255275


New Features

  • finagle-base-http: Add Message.httpDateFormat(millis) to format the epoch millis into an RFC 7231 formatted String representation. PHAB_ID=D234867
  • finagle-core: Introduce a StackClient.withStack overload that makes modifying the existing Stack easier when using method chaining. PHAB_ID=D234739
  • finagle-mysql: Introduce session to be able to perform multiple operations that require session state on a guaranteed single connection. PHAB_ID=D219322
  • finagle-netty4: When using the native epoll transport, finagle now publishes the TCP window size and number of retransmits based on the tcpInfo provided by from the channel. These stats are published with a debug verbosity level. PHAB_ID=D218772
  • finagle-http: HTTP clients and servers now accept fixedLengthStreamedAfter param in their withStreaming configuration (default: 5 MB when streaming is enabled). This new parameter controls the limit after which Finagle will stop aggregating messages with known Content-Length (payload will be available at .content) and switch into a streaming mode (payload will be available at .reader). Note messages with Transfer-Encoding: chunked never aggregated. PHAB_ID=D236573
  • finagle-thrift: tracing.thrift now has an optional timestamp field for a Span. PHAB_ID=D242204
  • finagle-zipkin-core: A Span now encodes a timestamp of when it was created as part of its thrift serialization. PHAB_ID=D242204

Breaking API Changes

  • finagle-http: c.t.f.http.param.MaxChunkSize has been removed. There is no good reason to configure it with anything but Int.MaxValue (unlimited). PHAB_ID=D233538
  • finagle-exp: Update DarkTrafficFilter#handleFailedInvocation to accept the request type for more fidelity in handling the failure. PHAB_ID=D237484

Runtime Behavior Changes

  • finagle-http: Unset maxChunkSize limit in Netty HTTP codecs. Now both clients and servers emit all available data as a single chunk so we can put it into use quicker. PHAB_ID=D233538
  • finagle-http: Streaming clients (withStreaming(true)) now aggregate inbound messages with known Content-Length if their payloads are less than 5mb (8k before). Use withStreaming(true, 32.kb) to override it with a different value. PHAB_ID=D234882
  • finagle-http2: HTTP/2 servers perform a more graceful shutdown where an initial GOAWAY is sent with the maximum possible stream id and waits for either the client to hang up or for the close deadline, at which time a second GOAWAY is sent with the true last processed stream and the connection is then closed. PHAB_ID=D206683


  • finagle-core: Deprecate EndpointerStackClient.transformed(Stack[ServiceFactory[Req, Rep]] => Stack[ServiceFactory[Req, Rep]]) in favor of the withStack variant. PHAB_ID=D234739



  • finagle-core: Deprecation warnings have been removed from the ‘status’, ‘onClose’, and ‘close’ methods on c.t.f.t.Transport, and added to the corresponding methods on c.t.f.t.TransportContext. PHAB_ID=D221528

Runtime Behavior Changes

  • finagle-netty3: Implementations for ‘status’, ‘onClose’, and ‘close’ methods have been moved from c.t.f.n.t.ChannelTransportContext to c.t.f.n.t.ChannelTransport. PHAB_ID=D221528


Breaking API Changes

  • finagle-base-http: DefaultHeaderMap now validates HTTP Header names and values in add and set. addUnsafe and setUnsafe have been created to allow adding and setting headers without validation. PHAB_ID=D217035
  • finagle-core: Remove slow host detection from ThresholdFailureDetector. PHAB_ID=D210015

Runtime Behavior Changes

  • finagle-core: When Finagle would exhaust a retry budget with an exception that was not a FailureFlags, previously it would wrap that exception with a non-retryable failure. This lead to surprising behavior for users. Those exceptions will no longer be wrapped. PHAB_ID=D216281
  • finagle-http: The finagle HTTP clients and servers now consider a Retry-After: 0 header to be a retryable nack. Servers will set this header when the response is a retryable failure, and clients will interpret responses with this header as a Failure.RetryableNackFailure. PHAB_ID=D216539


New Features

  • finagle-core: c.t.f.FailureFlags is now a public API. This is Finagle’s API for attaching metadata to an exception. As an example this is used to check if an exception is known to be safe to retry. Java compatibility has also been added. PHAB_ID=D202374
  • finagle-core: Introducing StackTransformer, a consistent mechanism for accessing and transforming the default ServerStack. PHAB_ID=D207980
  • finagle-netty4: Allow sockets to be configured with the [SO_REUSEPORT]( option when using native epoll, which allows multiple processes to bind and accept connections from the same port. PHAB_ID=D205535

Breaking API Changes

  • finagle: and are now abstracted over the type they produce/consume (Reader[A] and Writer[A]) and are no longer fixed to Buf. PHAB_ID=D195638
  • finagle-core: Address.hashOrdering now takes a seed parameter and PeerCoordinate.setCoordinate does not take a peerOffset any longer. PHAB_ID=D199545
  • finagle-core: Removed deprecated members c.t.f.Failure.{Interrupted, Ignorable, DeadlineExceeded, Rejected, NonRetryable, flagsOf}. PHAB_ID=D199361
  • finagle-core: SingletonPool now takes an additional parameter which indicates if interrupts should propagate to the underlying resource. PHAB_ID=D205433
  • finagle-core: Remove TimeoutFactory.Role in favor of passing a role to the module function. Since this module is a re-used within the client stack, it needs unique identifiers for each distinct module. PHAB_ID=D204647
  • finagle-core: the valid range for the argument to WindowedPercentileHistogram.percentile is now [0.0..1.0], e.g., 0.95 means 95th percentile. PHAB_ID=D198915
  • finagle-mux: The old pull-based mux implementations have been removed. PHAB_ID=D208737
  • finagle-netty3: The type of context of a ChannelTransport has been changed from a LegacyContext to a ChannelTransportContext. PHAB_ID=D205473
  • finagle-netty4: The type of context of a ChannelTransport has been changed from a Netty4Context to a ChannelTransportContext. PHAB_ID=D205794
  • finagle-netty4: c.t.f.netty4.param.useUnpoolledByteBufAllocator flag has been removed. There is no good reason to opt-out of a more efficient, pooled allocator. PHAB_ID=D212097
  • finagle-thrift: DeserializeCtx became ClientDeserializeCtx for client side response classification, add ServerDeserializeCtx to handle server side response classification. PHAB_ID=D196032
  • finagle-serversets: ZkMetadata.shardHashOrdering now takes a seed parameter. PHAB_ID=D199545

Bug Fixes

  • finagle-thrift: Thrift clients created via .servicePerEndpoint now propagate exceptions appropriately when the method return type is void. PHAB_ID=D200690
  • finagle-thrift, finagle-thriftmux: Response classification is enabled in server side. PHAB_ID=D196032

Runtime Behavior Changes

  • finagle-memcached: A Memcached client (c.t.f.Memcached.Client) is now backed by a more efficient, push-based implementation. PHAB_ID=D208047
  • finagle-netty4: Finagle’s Netty 4 implementation now defaults to use Linux’s native epoll transport, when available. Run with -com.twitter.finagle.netty4.useNativeEpoll=false to opt out. PHAB_ID=D208088


New Features

  • finagle-core: Introducing the new c.t.f.tracing.Tracing API for more efficient tracing (dramatically reduces the number of context lookups; see scaladoc for c.t.f.tracing.Trace). PHAB_ID=D190670
  • finagle-core: c.t.f.tracing.Trace facade API now provides forwarding record methods for all kinds of annotations and is a preffered way of recording traces. PHAB_ID=D192598
  • finagle-thriftmux: Promote the push-based ThriftMux implementation out of experimental status.``PHAB_ID=D189187``

Breaking API Changes

  • finagle-base-http: c.t.f.http.cookie.exp.supportSameSiteCodec has been moved out of the exp package to c.t.f.http.cookie.supportSameSiteCodec. PHAB_ID=D196517
  • finagle-core: Parameter-less annotation classes (c.t.f.tracing.Annotation) have been promoted to objects for efficiency reasons. PHAB_ID=D192598
  • finagle-core: c.t.f.tracing.Trace.record(Record) now accepts the record argument by value (previously by name). PHAB_ID=D193300
  • finagle-core: c.t.f.Failure.{Restartable, Interrupted, Ignorable, DeadlineExceeded, Wrapped, Rejected, NonRetryable} are deprecated in favor of the c.t.f.FailureFlags analogs. PHAB_ID=D195647
  • finagle-core: c.t.f.Leaf and c.t.f.Node are now private; use Stack.leaf and Stack.node instead. PHAB_ID=D195924
  • finagle-core: Marked transform in com.twitter.finagle.Stack as protected. It is too powerful and unnecessary for users, and should be for implementor use only. PHAB_ID=D195938
  • finagle-mysql: c.t.f.mysql.CanBeParameter’s implicit conversions timestampCanBeParameter, sqlDateCanBeParameter, and javaDateCanBeParameter have been consolidated into a single implicit, dateCanBeParameter. PHAB_ID=D195351

Bug Fixes

  • finagle-http2: Fixed a race condition caused by c.t.f.http.transport.StreamTransports being closed, but that status not being reflected right away, causing a second request to fail. PHAB_ID=D198198

Runtime Behavior Changes

  • finagle-core: c.t.f.tracing.Trace API is no longer guarding Trace.record calls behind Trace.isActivelyTracing. Add Trace.isActivelyTracing guards on the call sites if materializing tracing annotations is a performance concern. PHAB_ID=D193300
  • finagle-mysql: Clients will now issue a ROLLBACK each time a service is checked back into the connection pool. This can be disabled via Mysql.Client.withNoRollback. PHAB_ID=D196673
  • finagle-thriftmux: The push-based server muxer is now the default. In both synthetic tests and production it has shown signifcant performance benefits and is simpler to maintain. PHAB_ID=D193630
  • finagle-mysql: Remove deprecated TimestampValue.apply(Timestamp) and TimestampValue.unapply(value) methods. Use TimestampValue.apply(TimeZone, TimeZone) instead. PHAB_ID=D182920


  • finagle-mux: The pull based mux implementation, c.t.f.Mux, has been deprecated in favor of the push-based mux implementation, c.t.f.pushsession.MuxPush. PHAB_ID=D193630


New Features

  • finagle-core: Promote the push-based API’s out of experimental. For protocols that have eager read paths, for example multiplexed protocols and non-streaming clients, a push-based protocol implementation can provide significant performance benefits by avoiding the impedance mismatch between the underlying Netty framework and the pull-based Transport model. PHAB_ID=D189187
  • finagle-core: There is now an implicit instance for Finagle’s default timer: DefaultTimer.Implicit. PHAB_ID=D185896
  • finagle-core: Introduce new command-line flag c.t.f.tracing.enabled to entirely disable/enable tracing for a given process (default: true). PHAB_ID=D186557
  • finagle-mux: Promote the push-based Mux implementation out of experimental status. PHAB_ID=D189187
  • finagle-mysql: com.twitter.util.Time can now be used with PreparedStatement`s without converting the `ctu.Time to a java.sql.Timestamp. PHAB_ID=D182973
  • finagle-stats: Adds a lint rule to detect when metrics with colliding names are used. PHAB_ID=D183494
  • finagle-core: Client side NackAdmissionFilter can now be configured more easily by calling $client.withAdmissionControl.nackAdmissionControl(window, threshold). PHAB_ID=D188877
  • finagle-thrift: Trait c.t.scrooge.ThriftService is now c.t.finagle.thrift.ThriftService. Scrooge generated service objects now all inherit from c.t.finagle.thrift.GeneratedThriftService. PHAB_ID=D180341

Breaking API Changes

  • finagle-core: c.t.f.dispatch.ClientDispatcher.wrapWriteException has been turned from a partial function instance into a static total function. PHAB_ID=D189639
  • finagle-mux: ClientDiscardedRequestException now extends FailureFlags and is no longer a case class. PHAB_ID=D183456

Bug Fixes

  • finagle-core: c.t.f.filter.NackAdmissionFilter is now aware of FailureFlags encoded failures. PHAB_ID=D193390
  • finagle-mux: Mux’s server dispatcher is now aware of FailureFlags encoded failures. PHAB_ID=D193456

Runtime Behavior Changes

  • finagle-core: Server-side rejections from c.t.f.filter.RequestSempahoreFilter.module are now captured by c.t.f.service.StatsFilter. They will roll up under “/failures”, “/failures/rejected”, and “/failures/restartable” in stats. PHAB_ID=D187127
  • finagle-core: c.t.f.tracing.Trace.tracers now returns only distinct tracers stored in the local context (returned all tracers before). PHAB_ID=D188389
  • finagle-http: HTTP param decoding is no longer truncated to 1024 params. PHAB_ID=D190113
  • finagle-mux: When mux propagates an interrupt started by BackupRequestFilter over the network, the FailureFlags.Ignorable status is propagated with it. PHAB_ID=D183456


Runtime Behavior Changes

  • finagle-core: By default, the deterministic aperture load balancer doesn’t expand based on the loadband. This is because the loadband is influenced by a degree of randomness, and this breaks the deterministic part of deterministic aperture and can lead to aggressive banding on backends. PHAB_ID=D180922
  • finagle-http2: Unprocessed streams are retryable in case of GOAWAY. PHAB_ID=D174401

New Features

  • finagle-core: Add PropagateDeadlines Stack.Param to TimeoutFilter for disabling propagation of deadlines to outbound requests. PHAB_ID=D168405

  • finagle-core: Add toString implementations to c.t.finagle.Service and c.t.finagle.Filter. Update in Filter#andThen composition to expose a useful toString for composed Filters and a composed Service (a Filter chain with a terminal Service or ServiceFactory).

    The default implementation for Filter and Service is getClass.getName. When composing filters, the andThen composition method correctly tracks the composed parts to produce a useful toString, e.g.,


import com.twitter.finagle.{Filter, Service}
import com.twitter.util.Future

class MyFilter1 extends Filter[Int, Int, Int, Int] {
   def apply(request: Int, service: Service[Int, Int]): Future[Int] = ???

import com.twitter.finagle.{Filter, Service}
import com.twitter.util.Future

class MyFilter2 extends Filter[Int, Int, Int, Int] {
  def apply(request: Int, service: Service[Int, Int]): Future[Int] = ???
val filters = (new MyFilter1).andThen(new MyFilter2)

filters.toString would emit the String “”

If a Service (or ServiceFactory) were then added:

import com.twitter.finagle.{Filter, Service}
import com.twitter.finagle.service.ConstantService
import com.twitter.util.Future


val svc: Service[Int, Int] = filters.andThen(new ConstantService[Int, Int](Future.value(2)))

Then, svc.toString would thus return the String: “”

Filter implementations are permitted to override their toString implementations which would replace the default of getClass.getName. PHAB_ID=D172526

  • finagle-core: Make Filter.TypeAgnostic an abstract class for Java usability. PHAB_ID=D172716
  • finagle-core: c.t.f.filter.NackAdmissionFilter is now public. PHAB_ID=D177322
  • finagle-core: Extended c.t.f.ssl.KeyCredentials and c.t.f.ssl.TrustCredentials to work with and respectively. PHAB_ID=D177484

Breaking API Changes

  • finagle-core: Rename DeadlineFilter.Param(maxRejectFraction) to DeadlineFilter.MaxRejectFraction(maxRejectFraction) to reduce confusion when adding additional params. PHAB_ID=D172402

Bug Fixes

  • finagle-http2: StreamTransportFactory now marks itself as dead/closed when it runs out of HTTP/2 stream IDs instead of stalling. This allows the connection to be closed/reestablished in accordance with the spec PHAB_ID=D175898
  • finagle-netty4: SslServerSessionVerifier is now supplied with the proper peer address rather than Address.failing. PHAB_ID=D168334
  • finagle-thrift/thriftmux: Disabled client side per-endpoint stats by default for client ServicePerEndpoint. It can be set via c.t.f.thrift.RichClientParam or a with-method as Thrift{Mux}.client.withPerEndpointStats. PHAB_ID=D169427
  • finagle-netty4: Avoid NoClassDefFoundError if netty-transport-native-epoll is not available on the classpath.


New Features

  • finagle-base-http: Added ability to add SameSite attribute to Cookies to comply with The attribute may be set in the constructor via the c.t.f.http.Cookie sameSite param or via the c.t.f.http.Cookie.sameSite method. PHAB_ID=D157942
    • Pass SameSite.Lax to the Cookie to add the “Lax” attribute.
    • Pass SameSite.Strict to the Cookie to add the “Strict” attribute.
  • finagle-base-http: Introduced an API to extract query string params from a c.t.f.http.Request, c.t.f.http.Uri.fromRequest and c.t.f.http.Uri#params. PHAB_ID=D160298
  • finagle-mysql: Added APIs to Row which simplify the common access pattern. For example, Row.stringOrNull(columnName: String): String and Row.getString(columnName: String): Option[String]. PHAB_ID=D156926, PHAB_ID=D157360
  • finagle-mysql: Added read and modify APIs to c.t.f.mysql.Client and c.t.f.mysql.PreparedStatement for that return the specific type of Result for those operations, ResultSet and OK respectively. PHAB_ID=D160215
  • finagle-serversets: Zk2Session’s AsyncSemaphore which controls the maximum concurrent Zk operations is configurable (GlobalFlag c.t.f.serverset2.zkConcurrentOperations). `PHAB_ID=D157709`
  • finagle-mysql: Address CursoredStatement usability from Java via CursoredStatement.asJava(). Through this, you can use the API with varargs and Java 8 lambdas. PHAB_ID=D158399
  • finagle-toggle: Improved Java compatibility for ToggleMap and Toggle. PHAB_ID=D164489
  • finagle-toggle: StandardToggleMap.apply and StandardToggleMap.registeredLibraries now use ToggleMap.Mutable to better support mutating the underlying mutable ToggleMap. PHAB_ID=D167046

Breaking API Changes

  • finagle-mux: With the introduction of the push-based mux client, we’ve removed the need for the optimized c.t.f.Mux.Netty4RefCountingControl MuxImpl, which has been removed. PHAB_ID=D141010
  • finagle-mysql: now returns a Future[Unit] instead of the broad Future[Result] ADT. PHAB_ID=D160215
  • finagle-toggle: Changed ToggleMap.Mutable from a trait to an abstract class, and ToggleMap.Proxy no longer extends ToggleMap, but now has a self-type that conforms to ToggleMap instead. PHAB_ID=D164489

Runtime Behavior Changes

  • finagle-core: Add c.t.f.SslException to better model exceptions related to SSL/TLS. The c.t.f.ChannelException.apply method will now wrap`s in `c.t.f.SslException. PHAB_ID=D158344
  • finagle-core: MethodBuilder metrics now include failures. PHAB_ID=D167589, PHAB_ID=D168095
  • finagle-http: ServerAdmissionControl is circumvented for HTTP requests that have a body unless the request contains the header ‘finagle-http-retryable-request’ since it cannot be known whether the client can actually retry them, potentially resulting in depressed success rates during periods of throttling. PHAB_ID=D134209
  • finagle-http2: Clients and servers no longer attempt a cleartext upgrade if the first request of the HTTP/1.1 session has a body. PHAB_ID=D153986
  • finagle-thriftmux: The push-based client muxer is now the default muxer implementation. The push-based muxer has better performance and a simpler architecture. PHAB_ID=D158134
  • finagle-toggle: ToggleMap.Proxy#underlying is now public, and ToggleMap.Proxy participates in ToggleMap.components. PHAB_ID=D167046

Bug Fixes

  • finagle-base-http: Concurrent modification of the c.t.f.http.DefaultHeaderMap could result in an infinite loop due to HashMap corruption. Access is now synchronized to avoid the infinite loop. PHAB_ID=D159250
  • finagle-core: FailureFlags that have their flags set modified will now retain the original stack trace, suppressed Throwables, and cause when possible. PHAB_ID=D160402
  • finagle-memcached: Added the missing support for partial success for the batch operations in the new PartitioningService based Memcached client. PHAB_ID=D161249
  • finagle-thrift: Removed copied libthrift files. PHAB_ID=D165455
  • finagle-thrift/thriftmux: Server side per-endpoint statsFilter by default is disabled now. It can be set via c.t.f.thrift.RichServerParam or a with-method as Thrift{Mux}.server.withPerEndpointStats. PHAB_ID=D167433


New Features

  • finagle-core: c.t.f.filter.NackAdmissionFilter can now be disabled via a with-method. $Protocol.client.withAdmissionControl.noNackAdmissionControl PHAB_ID=D146873
  • finagle-mysql: Exceptions now include the SQL that was being executed when possible. PHAB_ID=D150503
  • finagle-mysql: Address PreparedStatement usability from Java via PreparedStatement.asJava(). Through this, you can use the API with varargs and Java 8 lambdas. PHAB_ID=D156755
  • finagle-mysql: Added support for Options to Parameter implicits. This allows for the natural representation of nullable columns with an Option where a None is treated as a null. PHAB_ID=D156186
  • finagle-netty4: Add ‘tls/connections’ gauge for Finagle on Netty 4 which tracks the number of open SSL/TLS connections per Finagle client or server. PHAB_ID=D144184
  • finagle-redis: Support has been added for a number of new cluster commands introduced in Redis 3.0.0. PHAB_ID=D152186

Bug Fixes

  • finagle-mysql: Fix handling of interrupts during transactions. PHAB_ID=D154441

Breaking API Changes

  • finagle-core: c.t.f.ssl.client.HostnameVerifier has been removed since it was using which is no longer accessible in JDK 9. PHAB_ID=D144149
  • finagle-thrift: Upgraded libthrift to 0.10.0, c.t.f.thrift.Protocols.TFinagleBinaryProtocol constructor now takes stringLengthLimit and containerLengthLimit, NO_LENGTH_LIMIT value changed from 0 to -1. PHAB_ID=D124620
  • finagle-thrift: Move “stateless” methods in c.t.finagle.thrift.ThriftRichClient to c.t.finagle.thrift.ThriftClient. Then mix the ThriftClient trait into the ThriftMux and Thrift Client companions to make it clearer that these stateless methods are not affected by the changing state of the configured client instance but are instead simply utility methods which convert or wrap the incoming argument. PHAB_ID=D143185
  • finagle-base-http: Removed deprecated c.t.f.Cookie.value_=; use c.t.f.Cookie.value instead. PHAB_ID=D148266
  • finagle-base-http: Removed deprecated c.t.f.Cookie.domain_=; use c.t.f.Cookie.domain instead. PHAB_ID=D148266
  • finagle-base-http: Removed deprecated c.t.f.Cookie.path_=; use c.t.f.Cookie.path instead. PHAB_ID=D148266

Runtime Behavior Changes

  • finagle-core: Add minimum request threshold for successRateWithinDuration failure accrual. PHAB_ID=D154129
  • finagle-core: c.t.f.filter.NackAdmissionFilter no longer takes effect when the client’s request rate is too low to accurately update the EMA value or drop requests. PHAB_ID=D143996
  • finagle-core: SSL/TLS client hostname verification is no longer performed by c.t.f.ssl.client.HostnameVerifier. The same underlying library is used to perform the hostname verification. However it now occurs before the SSL/TLS handshake has been completed, and the exception on failure has changes from a c.t.f.SslHostVerificationException to a PHAB_ID=D144149
  • finagle-core: Closing c.t.f.NullServer is now a no-op. PHAB_ID=D156098
  • finagle-netty4: Netty ByteBuf leak tracking is enabled by default. PHAB_ID=D152828


  • finagle-thrift: System property “-Dorg.apache.thrift.readLength” is deprecated. Use constructors to set read length limit for TBinaryProtocol.Factory and TCompactProtocol.Factory. PHAB_ID=D124620


New Features

  • finagle-core: c.t.f.client.BackupRequestFilter.filterService for wrapping raw services in a c.t.f.client.BackupRequestFilter is now public. PHAB_ID=D135484
  • finagle-core: Introduce c.t.f.Stacks.EMPTY_PARAMS for getting an empty Param map from Java, and for easily adding Params to a Param map from Java. PHAB_ID=D139660

Bug Fixes

  • finagle-core: c.t.f.liveness.FailureAccrualFactory takes no action on c.t.f.Failure.Ignorable responses. PHAB_ID=D135435
  • finagle-core: c.t.f.pool.WatermarkPool is resilient to multiple closes on a service instance. PHAB_ID=D137198
  • finagle-core: c.t.f.pool.CachingPool service wrapper instances are resilient to multiple closes. PHAB_ID=D136781
  • finagle-core: Requeue module now closes sessions it prevented from propagating up the stack. PHAB_ID=D142457
  • finagle-base-http: c.t.f.http.Netty4CookieCodec.encode now wraps Cookie values that would be wrapped in c.t.f.http.Netty3CookieCodec.encode. PHAB_ID=D134566
  • finagle-base-http: c.t.f.http.Cookie.maxAge returns c.t.f.http.Cookie.DefaultMaxAge (instead of null) if maxAge has been set to null or None in the copy constructor PHAB_ID=D138393.
  • finagle-http: The HTTP client will not attempt to retry nacked requests with streaming bodies since it is likely that at least part of the body was already consumed and therefore it isn’t safe to retry. PHAB_ID=D136053

Breaking API Changes

  • finagle-base-http: Removed c.t.f.http.Cookie.comment_, c.t.f.http.Cookie.comment_=, c.t.f.http.Cookie.commentUrl_, and c.t.f.http.Cookie.commentUrl_=. comment and commentUrl per RFC-6265. PHAB_ID=D137538
  • finagle-base-http: Removed deprecated c.t.f.http.Cookie.isDiscard and c.t.f.http.Cookie.isDiscard_=, per RFC-6265. PHAB_ID=D138109
  • finagle-base-http: Removed deprecated c.t.f.http.Cookie.ports and c.t.f.http.Cookie.ports_=, per RFC-6265. PHAB_ID=D139243
  • finagle-base-http: c.t.f.http.RequestBuilder has been moved to the finagle-http target and the implicit evidence, RequestConfig.Yes has been renamed to RequestBuilder.Valid. PHAB_ID=D122227
  • finagle-base-http: Removed deprecated c.t.f.Cookie.isSecure; use instead. Removed deprecated c.t.f.Cookie.isSecure_=. PHAB_ID=D140435
  • finagle-base-http: Removed deprecated c.t.f.http.Cookie.version and c.t.f.http.Cookie.version_=, per RFC-6265. PHAB_ID=D142672
  • finagle-base-http: Removed deprecated c.t.f.Cookie.httpOnly_=; use c.t.f.Cookie.httpOnly instead. PHAB_ID=D143177
  • finagle-base-http: Removed deprecated c.t.f.Cookie.maxAge_=; use c.t.f.Cookie.maxAge instead. PHAB_ID=D143177
  • finagle-core: c.t.f.pool.WatermarkPool was finalized. PHAB_ID=D137198
  • finagle-core: c.t.finagle.ssl.Ssl and related classes have been removed. They were replaced as the primary way of using SSL/TLS within Finagle in release 6.44.0 (April 2017). Please migrate to using c.t.f.ssl.client.SslClientEngineFactory or c.t.f.ssl.server.SslServerEngineFactory instead. PHAB_ID=D135908
  • finagle-core: Removed newSslEngine and newFinagleSslEngine from ServerBuilder. Please implement a class which extends c.t.f.ssl.server.SslServerEngineFactory with the previously passed in function used as the implementation of the apply method. Then use the created engine factory with one of the tls methods instead. PHAB_ID=D135908
  • finagle-core: The deprecated c.t.f.loadbalancer.DefaultBalancerFactory has been removed. PHAB_ID=D139814
  • finagle-exp: The deprecated c.t.f.exp.BackupRequestFilter has been removed. Please use c.t.f.client.BackupRequestFilter instead. PHAB_ID=D143333
  • finagle-http: Removed the c.t.f.Http.Netty3Impl. Netty4 is now the only underlying HTTP implementation available. PHAB_ID=D136705
  • finagle-zipkin-scribe: Renamed the finagle-zipkin module to finagle-zipkin-scribe, to better advertise that this is just the scribe implementation, instead of the default. PHAB_ID=D141940


New Features

  • finagle-core: Add orElse to allow composition of FailureAccrualPolicy`s. ``PHAB_ID=D131156`
  • finagle-core: c.t.f.http.MethodBuilder now exposes a method newService without a methodName to create a client. c.t.f.thriftmux.MethodBuilder now exposes a method servicePerEndpoint without a methodName to create a client. PHAB_ID=D131809
  • finagle-thriftmux: Expose the underlying configured client label in the c.t.finagle.thriftmux.MethodBuilder. PHAB_ID=D129109

Bug Fixes

  • finagle-http2: http2 servers no longer leak ping bodies. PHAB_ID=D130503


  • finagle-core: c.t.finagle.ssl.Ssl and related classes have been deprecated. They were replaced as the primary way of using SSL/TLS within Finagle in release 6.44.0 (April 2017). Please migrate to using c.t.f.ssl.client.SslClientEngineFactory or c.t.f.ssl.server.SslServerEngineFactory instead. PHAB_ID=D129692

Breaking API Changes

  • finagle-base-http: c.t.f.h.codec.HttpCodec has been moved to the finagle-http project. PHAB_ID=D116364
  • finagle base-http: c.t.f.h.Request.multipart has been removed. Use c.t.f.h.exp.MultipartDecoder instead. PHAB_ID=D129158
  • finagle-http: Split the toggle ‘c.t.f.h.UseH2C’ into a client-side toggle and a server-side toggle, named ‘c.t.f.h.UseH2CClients’, and ‘c.t.f.h.UseH2CServers’, respectively. PHAB_ID=D130988

Runtime Behavior Changes

  • finagle-core: Finagle clients with retry budgets or backoffs should no longer have infinite hash codes. PHAB_ID=D128594
  • finagle-core: c.t.f.l.Balancer no longer uses a c.t.f.u.Updater as its underlying concurrency primitive as it was found that in practice coalescing updates almost never happens and in the absence of that Updater imposes more overhead than simple synchronization while complicating the result of calling rebuild() since we don’t know if the rebuild actually occurred by the time we attempt to use the distributor again. PHAB_ID=D126486


New Features

  • finagle-core: FailureDetector has a new method, onClose, which provides a Future that is satisfied when the FailureDetector marks a peer as Closed. PHAB_ID=D126840
  • finagle-core: Introduce trace logging of requests as they flow through a Finagle client or server. These logs can be turned on at runtime by setting the “com.twitter.finagle.request.Logger” logger to trace level. PHAB_ID=D124352
  • finagle-http2: HTTP/2 clients now expose the number of currently opened streams under the $client/streams gauge. PHAB_ID=D127238
  • finagle-http2: HTTP/2 servers now expose the number of currently opened streams under the $server/streams gauge. PHAB_ID=D127667
  • finagle-memcached: By default, the Memcached client now creates two connections to each endpoint, instead of 4. PHAB_ID=D119619
  • finagle-redis: Add support for redis Geo Commands. PHAB_ID=D123167 based on the PR written by Mura-Mi []
  • finagle-thrift: Add c.t.f.thrift.service.ThriftServiceBuilder and c.t.f.thrift.service.ReqRepThriftServiceBuilder for backwards compatibility of creating higher-kinded method-per-endpoint clients. PHAB_ID=D127538
  • finagle-core: c.t.f.http.MethodBuilder and c.t.f.thriftmux.MethodBuilder now expose idempotent and nonIdempotent methods, which can be used to configure retries and the sending of backup requests. PHAB_ID=D122087

Bug Fixes

  • finagle-mysql: Fix a bug with transactions where an exception during a rollback could leave the connection with a partially committed transaction. PHAB_ID=D122771
  • finagle-toggle: c.t.f.toggle.Toggle`s are independent; that is, applying the same value to two different toggles with the same fraction will produce independent true/false values. ``PHAB_ID=D128172`

Runtime Behavior Changes

  • finagle-core, finagle-netty4: When creating engines, SslClientEngineFactories now use SslClientEngineFactory.getHostString instead of SslClientEngineFactory.getHostname. This no longer performs an unnecessary reverse lookup when a hostname is not supplied as part of the SslClientConfiguration. PHAB_ID=D124369
  • finagle-http2: Supplies a dependency on io.netty.netty-tcnative-boringssl-static, which adds support for ALPN, which is necessary for encrypted http/2. To use a different static ssl dependency, exclude the tcnative-boringssl dependency and manually depend on the one you want to use. PHAB_ID=D119555

Breaking API Changes

  • finagle-base-http, finagle-http: Removed Apache Commons Lang dependency, org.apache.commons.lang3.time.FastDateFormat now is java.time.format.DateTimeFormatter. PHAB_ID=D121479
  • finagle-base-http: c.t.f.http.Message.headerMap is now an abstract method. PHAB_ID=D120931
  • finagle-core: c.t.f.ssl.server.SslServerSessionVerifier no longer uses the unauthenticated host information from SSLSession. PHAB_ID=D124815
  • finagle-memcached: ConcurrentLoadBalancerFactory was removed and its behavior was replaced by a Stack.Param inside finagle-core’s LoadBalancerFactory. PHAB_ID=D119394
  • finagle-netty4: Netty4ClientEngineFactory and Netty4ServerEngineFactory were finalized. PHAB_ID=D128708
  • finagle-thrift, finagle-thriftmux: Remove ReqRep specific methods. Since the “ReqRep” builders are now subclasses of their non-“ReqRep” counterparts their is no longer a need to expose “ReqRep” specific methods. PHAB_ID=D123341


  • finagle-exp: c.t.f.exp.BackupRequestFilter has been deprecated. Please use c.t.f.client.BackupRequestFilter instead. PHAB_ID=D122344
  • finagle-http: c.t.f.http.Request.multipart has been deprecated. Use c.t.f.http.exp.MultipartDecoder instead. PHAB_ID=D126013


New Features

  • finagle-core: Expose Tunables for MethodBuilder timeout configuration. Update the http.MethodBuilder and thriftmux.MethodBuilder to accept Tunables for configuring total and per-request timeouts. PHAB_ID=D118114
  • finagle-thrift, finagle-thriftmux: Add support for Scrooge ReqRepServicePerEndpoint functionality. PHAB_ID=D107397
  • finagle-thriftmux: Add support for Scrooge ServicePerEndpoint and ReqRepServicePerEndpoint functionality to thriftmux.MethodBuilder. PHAB_ID=D116081

Breaking API Changes

  • finagle-base-http: Remove deprecated [Request|Response].[encode|decode][Bytes|String] methods. Use c.t.f.h.codec.HttpCodec methods instead. PHAB_ID=D116350
  • finagle-memcached: ConcurrentLoadBalancerFactory was removed and its behavior was replaced by a Stack.Param inside finagle-core’s LoadBalancerFactory. PHAB_ID=D119394
  • finagle-serversets: Removed Guava dependency which broke some APIs. PHAB_ID=D119555
    • c.t.f.common.zookeeper.ServerSets.TO_ENDPOINT is now a java.util.function.Function.
    • now takes a java.util.Set.
    • c.t.f.common.zookeeper.ZooKeeperUtils.OPEN_ACL_UNSAFE is is now a java.util.List.
    • c.t.f.common.zookeeper.ZooKeeperUtils.EVERYONE_READ_CREATOR_ALL is is now a java.util.List.
    • c.t.f.common.zookeeper.ZooKeeperClient constructor now takes a java.util.Optional.
  • finagle-thrift: Move ThriftRichClient and ThriftRichServer to c.t.finagle.thrift package. PHAB_ID=D115284

Runtime Behavior Changes

  • finagle-core: Remove NackAdmissionControl from the default client stack. Add it to the finagle-{http,mux} client stacks; note that it is added to finagle-http2 via finagle-http and finagle-thriftmux via finalge-mux. It is no longer part of the finagle-{memcached,mysql,redis} client stacks. PHAB_ID=D116722
  • finagle-core: The “pipelining/pending” stat has been removed from protocols using c.t.f.dispatch.PipeliningClientDispatcher. Refer to the “pending” stat for the number of outstanding requests. PHAB_ID=D113424
  • finagle-thrift,thriftmux: Tracing of RPC method names has been removed. This concern has moved into Scrooge. PHAB_ID=D115294


  • finagle-core: c.t.f.BackupRequestLost has been deprecated. Please use a c.t.f.Failure flagged c.t.f.Failure.Ignorable instead. PHAB_ID=D113466


New Features

  • finagle-core: Add ResponseClassifier`s, RetryOnTimeout and RetryOnChannelClosed, for exceptions that are commonly retried when building from ClientBuilder but had no MethodBuilder equivalents. ``PHAB_ID=D106706`
  • finagle-netty4: Netty4Transporter and Netty4Listener are now accessible, which allows external users to create their own protocols for use with Finagle on Netty 4. PHAB_ID=D105627

Bug Fixes

  • finagle-exp: Fix race condition in LatencyHistogram which could lead to the wrong value returned for quantile. PHAB_ID=D106330

Breaking API Changes

  • finagle-core: Numerous overloads of c.t.f.Server.serve have been marked final. PHAB_ID=D107280
  • finagle-thrift: Correctly send mux.Request#contexts in all cases. There were some cases in which mux.Request#contexts were not always propagated. The contexts are now always written across the transport. Note that there may be duplicated contexts between “local” context values and “broadcast” context values. Local values will precede broadcast values in sequence. PHAB_ID=D107921


Release Version Format

  • From now on, release versions will be based on release date in the format of YY.MM.x where x is a patch number. PHAB_ID=D101244

New Features

  • finagle-core: DeadlineFilter may now be created from the class and used as a regular Filter in addition to a stack module as before. PHAB_ID=D94517
  • finagle-mysql: Add ability to toggle the CLIENT_FOUND_ROWS flag. PHAB_ID=D91406
  • finagle-http: Separated the DtabFilter.Extractor from the ServerContextFilter into a new module: ServerDtabContextFilter. While this is still enabled in the default Http server stack, it can be disabled independently of the ServerContextFilter. PHAB_ID=D94306

Runtime Behavior Changes

  • finagle-netty4: Netty4ClientEngineFactory and Netty4ServerEngineFactory now validate loaded certificates in all cases to ensure that the current date range is within the validity range specified in the certificate. PHAB_ID=D88664
  • finagle-netty4: TrustCredentials.Insecure now works with native SSL/TLS engines. PHAB_ID=D103766
  • finagle-http2: Upgraded to the new netty http/2 API in netty version 4.1.16.Final, which fixes several long-standing bugs but has some bugs around cleartext http/2. One of the work-arounds modifies the visibility of a private field, so it’s incompatible with security managers. This is only true for http/2–all other protocols will be unaffected. PHAB_ID=D98069
  • finagle-http: Netty 3 HeaderMap was replaced with our own implementation. PHAB_ID=D99127


  • finagle-base-http: With the intention to make c.t.f.http.Cookie immutable, set methods on c.t.f.http.Cookie have been deprecated:

    • comment_=
    • commentUrl_=
    • domain_=
    • maxAge_=
    • path_=
    • ports_=
    • value_=
    • version_=
    • httpOnly_=
    • isDiscard_=
    • isSecure_=

    Use the c.t.f.http.Cookie constructor to set domain, maxAge, path, value, httpOnly, and secure. comment, commentUrl, ports, version, and discard have been removed per RFC-6265. PHAB_ID=D82164.

    Alternatively, use the domain, maxAge, path, httpOnly, and secure methods to create a new Cookie with the existing fields set, and the respective field set to a given value. PHAB_ID=D83226

  • finagle-base-http: c.t.f.http.Cookie.isSecure and c.t.f.http.Cookie.isDiscard have been deprecated. Use for c.t.f.http.Cookie.isSecure. isDiscard has been removed per RFC-6265. PHAB_ID=D82164

Breaking API Changes

  • finagle-mysql: Moved Cursors.cursor method to Client trait, and removed Cursors trait. This allows cursor queries to used with transactions. PHAB_ID=D91789
  • finagle-mux: Expose transport contexts in mux.Request and mux.Response. PHAB_ID=D92998
  • finagle-mux: The “leased” gauge has been removed from the mux client implementation since the metric is reported as the sum of the value over all clients which is unlikely to be useful. PHAB_ID=D100357


New Features

  • finagle-core: If a c.t.u.tunable.Tunable request or total timeout has been configured on a client which uses a c.t.f.client.DynamicTimeout filter, the current value of tunable will be used in the case of no dynamic timeout set for a request. PHAB_ID=D81886
  • finagle-core: FailFastException now captures the throwable that caused it. PHAB_ID=D86396
  • finagle-redis: finagle interface for redis DBSIZE command. PHAB_ID=D85305

Bug Fixes

  • finagle-core: Unregister ServerRegistry entry on StackServer#close. A StackServer entry is registered in the ServerRegistry on serve of the server but never unregistered. It is now unregistered on close of the StackServer. PHAB_ID=D83200
  • finagle-mux: Fix two issues with mux leases. In one bug, a new lease wouldn’t be sent to the client if it was issued within 1 second of when the existing lease was set to expire. In a second bug, the server would only nack if the issued lease was 0, but didn’t consider whether the lease had expired. PHAB_ID=D91645
  • finagle-netty4: Netty4ClientEngineFactory and Netty4ServerEngineFactory now properly load all chain certificates when the SslClientConfiguration or SslServerConfiguration uses KeyCredentials.CertKeyAndChain instead of just the first one in the file. PHAB_ID=D82414
  • finagle-thrift/thriftmux: Thrift/ThriftMux servers and clients now can be configured with withMaxReusableBufferSize to specify the max size of the reusable buffer for Thrift responses. PHAB_ID=D83190

Runtime Behavior Changes

  • finagle-stats: Verbosity levels are now respected: debug-metrics aren’t exported by default. PHAB_ID=D85278
  • finagle-netty4: ChannelTransport no longer considers the Channel.isWritable result when determining status. PHAB_ID=D82670


  • finagle-base-http: Encoding/decoding methods on c.t.f.http.Request and c.t.f.http.Response to/from Strings and arrays of bytes have been deprecated. Use the methods on c.t.f.http.codec.HttpCodec instead:

    • For c.t.f.http.Request.encodeString, use c.t.f.Http.codec.HttpCodec.encodeRequestToString
    • For c.t.f.http.Request.encodeBytes, use c.t.f.Http.codec.HttpCodec.encodeRequestToBytes
    • For c.t.f.http.Request.decodeString, use c.t.f.Http.codec.HttpCodec.decodeStringToRequest
    • For c.t.f.http.Request.decodeBytes`, use c.t.f.Http.codec.HttpCodec.decodeBytesToRequest
    • For c.t.f.http.Response.encodeString, use c.t.f.Http.codec.HttpCodec.encodeResponseToString
    • For c.t.f.http.Response.decodeString, use c.t.f.Http.codec.HttpCodec.decodeStringToResponse
    • For c.t.f.http.Response.decodeBytes, use c.t.f.Http.codec.HttpCodec.decodeBytesToResponse


Breaking API Changes

  • finagle-core: Remove deprecated method httpProxyTo(String, Option[Transporter.Credentials]). Use httpProxyTo(String, Transporter.Credentials] instead. PHAB_ID=D84077
  • finagle-*-http: Netty 3 specific HTTP transport related code has been moved into its own project, finagle-netty3-http, in preparation for removing it from Finagle. PHAB_ID=D84101
  • finagle-memcached: Remove deprecated method BaseClient.release(). Use BaseClient.close() instead. PHAB_ID=D83168


  • finagle-memcached: Move to c.t.f.memcached.JavaClient, to c.t.f.memcached.JavaClientBase, and to c.t.f.memcached.ResultWithCAS. PHAB_ID=D83719
  • finagle-core: Added a new type member Context to Transport, and a method that returns a context, which has most of the methods currently directly on Transport. Also deprecates most of those methods–please start using the context instead of the Transport directly. Also added type parameters to Transporter, Listener, and type members to StackClient and StackServer. PHAB_ID=D83972
  • finagle-core: com.twitter.finagle.loadbalancer.DeterministicOrdering was renamed to com.twitter.finagle.loadbalancer.ProcessCoordinate and the internal Coord ADT was changed as well. PHAB_ID=D84452
  • finagle-thrift: Move Thrift.Server.param.MaxReusableBufferSize to Thrift.param.MaxReusableBufferSize for both server and client use. PHAB_ID=D83190


New Features

  • finagle-core: A StackClient can be configured with a c.t.u.tunable.Tunable request timeout using .withRequestTimeout(tunable); this facilitates changing the timeout at runtime, without server restart. See for details. PHAB_ID=D80751.
  • finagle-core: SslClientSessionVerifier and SslServerSessionVerifier have been added as Stack params for executing custom SSL/TLS Session verification logic on the establishment of an SSL/TLS Session. PHAB_ID=D63256
  • finagle-core: tls methods which take an SslClientSessionVerifier have been added to ClientBuilder and ClientTransportParams (withTransport.tls). tls methods which take an SslServerSessionVerifier have been added to ServerBuilder and ServerTransportParams (withTransport.tls). PHAB_ID=D68645
  • finagle-core: Timer tasks submitted to the c.t.f.util.DefaultTimer can have their execution time monitored. Slow executing tasks may result in a log message at level WARN and a counter of slow tasks is kept under finagle/timer/slow. This can be enabled using the global flag c.t.f.util.defaultTimerProbeSlowTasks and the maximum allowed runtime and minimum duration between log messages can be tuned using the global flags c.t.f.util.defaultTimerSlowTaskMaxRuntime, and c.t.f.util.defaultTimerSlowTaskLogMinInterval, respectively. PHAB_ID=D70279
  • finagle-core: The JVM metrics for GC, allocations, memory, and more have moved here from TwitterServer. See the new JVM section in the user guide for details: PHAB_ID=D80883
  • finagle-http, finagle-thriftmux: MethodBuilder has been promoted out of experimental. MethodBuilder is a collection of APIs for client configuration at a higher level than the Finagle 6 APIs while improving upon the deprecated ClientBuilder. See the user guide for details: PHAB_ID=D60032
  • finagle-http: add withNoAutomaticContinue api to disable automatically sending 100 CONTINUE responses. PHAB_ID=D80017
  • finagle-http: The nack related logic in the c.t.f.h.c.HttpClientDispatcher has been moved into a filter, c.t.f.h.f.ClientNackFilter which has been added to the client stack and can now be removed based on its Stack.Role. PHAB_ID=D78902
  • finagle-init: Introduce a module to support service-loading initialization code. PHAB_ID=D75950
  • finagle-memcached: Added support for partitioned backends in finagle client. Introducing the new PartitioningService (PHAB_ID=D75143), KetamaPartitioningService (PHAB_ID=D77499) and MemcachedPartitioningService (PHAB_ID=D78927), which provide this support at different levels of abstraction. The c.t.f.Memcached util, that is used for creating new memcached clients, now creates a new partitioning client that utilizes these new services for the Memcached protocol. The new memcached client can be enabled by setting the toggle “com.twitter.finagle.memcached.UsePartitioningMemcachedClient” to 1.0. PHAB_ID=D80352
  • finagle-mux: Default to new more efficient decoder. PHAB_ID=D80225
  • finagle-mysql: IsolationLevel support was added with Transactions.transactionWithIsolation method, so the default level can be overridden at the transaction level. PHAB_ID=D68944
  • finagle-mysql: Add support for unsigned integers. When enabled, unsigned integers that do not fit into the existing signed representation are widened. For example an unsigned Int32 is represented as a Java Long, etc. Because this changes the c.t.f.mysql.Value variant returned by the row, it is disabled by default and must be enabled with the param c.t.f.Mysql.param.UnsignedColumns. PHAB_ID=D78721
  • finagle-netty4: Adds support for passing a chain file to the default TLS implementation. PHAB_ID=D59531
  • finagle-netty4: Netty 4 transports now use pooled allocators by default. PHAB_ID=D75014
  • finagle-netty4: KeyCredentials.CertKeyAndChain is now available to use with Netty4ServerEngineFactory. PHAB_ID=D80494
  • finagle-netty4: c.t.f.netty4.trackReferenceLeaks is now a CLI flag (default: disabled) rather than a toggle. PHAB_ID=D80654
  • finagle-stats: Metrics now report verbosity levels via MetricsView.verbosity. PHAB_ID=D78150
  • finagle-stats: JsonExporter now respects verbosity levels (current default behavior is to keep exporting “debug” metrics). Adjust com.twitter.finagle.stats.verbose tunable allowlist to change it. PHAB_ID=D79571
  • finagle-tunable: StandardTunableMap is now public. Users can access file-based, in-memory, and service-loaded tunable values using the map. See for details. PHAB_ID=D80751.
  • finagle: Changed dependencies of Netty from 4.1.10 to 4.1.12. PHAB_ID=D60438

Bug Fixes

  • finagle-mysql: Fix decoding error for medium length integers. PHAB_ID=D78505

Breaking API Changes

  • finagle: Finagle is now decoupled from Netty 3. Depend on finagle-netty3 explicitly if needed. PHAB_ID=D65268
  • finagle-base-http: The HTTP message model has been refactored to remove backing Netty 3 types. Additionally, the Request and Response classes now have private constructors to enforce a more appropriate inheritance model: Request.Proxy and Response.Proxy are now the point of entry for extending the HTTP model types. Along with the model changes the InputStream generated .getInputStream() method of HTTP messages no longer consumes the messages body. PHAB_ID=D74519
  • finagle-core: The Framer type has been transformed into a specialized version of a more generic abstraction, Decoder[T]. PHAB_ID=D59495
  • finagle-core: Replace the c.t.f.context.RemoteInfo.Available constructor which takes ClientId in favor of a version taking String. ClientId is Twitter’s Thrift specific concept and this should be more generic. PHAB_ID=D60136
  • finagle-core: Remove the ability to set a global address sort. This is no longer necessary as setting this per client is sufficient. PHAB_ID=D60698
  • finagle-core: Remove global flag com.twitter.finagle.tracing.debugTrace. This functionality is better suited as a concrete Tracer implementation instead of mixed into the generic code. PHAB_ID=D63252
  • finagle-core: PHAB_ID=D63526
    • ClientBuilder.codec and ServerBuilder.codec have been removed. Use .stack instead.
    • ClientBuilder.channelFactory and ServerBuilder.channelFactory have been removed.
      Use .stack instead.
  • finagle-core: LoadBalancerFactory now takes Stack.Params which allows a client to more easily pass in the stack context. PHAB_ID=D73129
  • finagle-memcached: Add c.t.util.Closable trait to c.t.f.memcached.BaseClient. PHAB_ID=D63970
  • finagle-mysql: A number of implementation details were made private such as specific Row implementations and ResultSet builder functions that consume raw packets. PHAB_ID=D78721
  • finagle-netty4-http: HTTP/1.1 implementation based on Netty 4 is no longer experimental and is moved out of the exp package. PHAB_ID=D80181
  • finagle-serversets: Remove ZkMetaData.AddressOrdering`, it is no longer used. PHAB_ID=D60698
  • finagle-stats: c.t.f.stats.MetricsStatsReceiver no longer has constructor variants which take a as util-events is now deprecated. PHAB_ID=D64437
  • finagle-thrift: The Netty3 thrift implementation has been removed. PHAB_ID=D63670
  • finagle-zipkin-core: c.t.f.zipkin.core.SamplingTracer no longer has constructor which takes a as util-events is now deprecated. PHAB_ID=D64437
  • finagle-zipkin: Zipkin Tracer now exports only three counters: requests, failures, success. PHAB_ID=D71965

Runtime Behavior Changes

  • finagle-core: The AsyncSemaphore which sequences dispatches in GenSerialClientDispatcher is now failed with a retryable Failure so that the retry logic knows that requests that which failed to acquire the semaphore are safe to retry. PHAB_ID=D78904
  • finagle-http: serverErrorsAsFailuresV2 toggle is turned into a flag serverErrorsAsFailures. PHAB_ID=D73265
  • finagle-http: Dispatcher stats are now exported under the client scope like all other client stats.``PHAB_ID=D72265``
  • finagle-http: It’s now possible to send a response from the HTTP server that has a Content-Length header so long as the ‘Transfer-Encoding: chunked’ isn’t set on the response. PHAB_ID=D80087
  • finagle-http: Non-streaming servers strip ‘expect’ headers when a 100 CONTINUE response is sent. PHAB_ID=D80017
  • finagle-serversets: Stabilizer is no longer exporting pending_tasks and deviation_ms stats. See notify_ms instead. PHAB_ID=D65571
  • finagle-stats, finagle-zipkin-core: No longer publishing as util-events is now deprecated. PHAB_ID=D64437
  • finagle-stats: No longer backed by commons metrics, now its own thing. PHAB_ID=D73497
  • finagle-netty4: Unset Netty’s default timeout (10 seconds) for SSL handshake on clients. Use .withSession.acquisitionTimeout instead. PHAB_ID=D78500


New Features

  • finagle: Changed dependencies of Netty from 4.1.9 to 4.1.10 and tcnative from 2.0.0 to 2.0.1. RB_ID=916056
  • finagle-core: c.t.f.n.ssl.SslConnectHandler is no longer exported publicly. It has also been renamed to c.t.f.n.ssl.client.SslClientConnectHandler. RB_ID=916932
  • finagle-core: c.t.f.factory.ServiceFactoryCache is now exported publicly. RB_ID=915064
  • finagle-core: Allow customization of load balancer behavior when no nodes are Status.Open. See the user guide for details: RB_ID=916145
  • finagle-core: The global c.t.f.naming.NameInterpreter can be optionally set using service loader. RB_ID=917082
  • finagle-redis: Support scanning over sets and sorted sets with SSCAN and ZSCAN. RB_ID=916484

Bug Fixes

  • finagle-mux: Disable Netty4RefCountingControl decoder when message fragmentation is enabled. PHAB_ID=D58153
  • finagle: Fixed Java API for withStack for Client and Server implementations. Java users now get the correct types for calls such as c.t.f.Http.client().withStack and c.t.f.Http.server().withStack. RB_ID=915440
  • finagle-thrift, finagle-thriftmux: Clients created using newServiceIface now use the configured c.t.f.service.ResponseClassifier (or c.t.f.service.ResponseClassifier.Default if not configured) for per-method stats and usage in c.t.f.liveness.FailureAccrualFactory and c.t.f.stats.StatsFilter. RB_ID=917010

Runtime Behavior Changes

  • finagle: Add a floor of 8 to the default values of the flags c.t.f.netty3.numWorkers and c.t.f.netty4.numWorkers. RB_ID=916465
  • finagle-core: c.t.f.util.DefaultTimer is decoupled from Netty 3 and is loaded via the LoadService machinery. If no timers are available on the class path, the JavaTimer instead is used instead. This ony affects direct usages of DefaultTimer as all Finagle protocols are using Netty 4 HashedWheelTimer at this point. RB_ID=915924
  • finagle-core: The load balancer implementations no longer close the endpoint resources when they are closed. Instead, they treat them as externally managed resources and expect the layers above to manage them. No change is required if using the Balancers in the context of a Finagle client. If that’s not the case, however, managing the life cycle of the passed in endpoints is necessary. RB_ID=916415
  • finagle-core: Aperture load balancers now expire idle sessions which fall out of the aperture window. RB_ID=916508
  • finagle-http: Uses Netty 4 as the default transport implementation. Use .configured(Http.Netty3Impl) to switch implementation over to Netty 3. PHAB_ID=D58698 RB_ID=917936
  • finagle-memcached: If the client decoder detects a protocol failure, the ClientTransport will close the connection. RB_ID=917685
  • finagle-netty4: poolReceiveBuffers toggle is removed (suppressed by UsePooling). RB_ID=917912
  • finagle-http: To conform to RFC 2616, a message body is NO LONGER sent when 1xx, 204 and 304 responses are returned. To conform with RFC 7230, a Content-Length header field is NOT sent for 1xx and 204 responses. Both rules are enforced even if users intentionally add body data or the header field for these responses. If violation of these rules is detected then an error message is logged. RB_ID=917827

Breaking API Changes

  • finagle: $protocol.Client.params/stack and $protocol.Server.params/stack are removed, use similar methods on instances instead: $protocol.client.params/stack and $protocol.server.params/stack instead. RB_ID=915703

  • finagle-core: Remove deprecated c.t.f.builder.ClientBuilder.tracerFactory. Use c.t.f.builder.ClientBuilder.tracer instead. Remove deprecated c.t.f.tracing.Tracer.Factory. Use c.t.f.tracing.Tracer instead. RB_ID=915481

  • finagle-core: Remove deprecated c.t.f.Deadline. Use c.t.f.context.Deadline instead. RB_ID=915550

  • finagle-core: Remove deprecated c.t.f.builder.ClientBuilder.cluster and Use c.t.f.builder.ClientBuilder.dest instead. RB_ID=915098

  • finagle-core: Remove deprecated c.t.f.tracing.Trace.recordRpcName. Use c.t.f.tracing.Trace.recordRpc and c.t.f.tracing.Trace.recordServiceName instead. RB_ID=916426

  • finagle-core: Remove deprecated c.t.f.builder.Cluster. Use com.twitter.finagle.Name to represent clusters instead. RB_ID=916162

  • finagle-core: LoadBalancerFactory now takes an EndpointFactory which is an extension of ServiceFactory that carries an address and has the ability to be rebuilt. RB_ID=916956

  • finagle-base-http: Remove deprecated c.t.f.http.Message.ContentTypeWwwFrom. Use c.t.f.http.Message.ContentTypeWwwForm instead. RB_ID=915543

  • finagle-exception: Remove deprecated c.t.f.exception.Reporter.clientReporter and c.t.f.exception.Reporter.sourceReporter. Use c.t.f.exception.Reporter.monitorFactory instead. RB_ID=916403

  • finagle-http: Remove deprecated c.t.f.http.HttpMuxer.pattern. Specify a route using c.t.f.http.HttpMuxer.route(pattern, this) instead. RB_ID=915551

  • finagle-http: Remove deprecated c.t.f.http.filter.ValidateRequestFilter. Create a custom filter if this behavior is needed. RB_ID=915548

  • finagle-kestrel: Remove deprecated methods on c.t.f.kestrel.MultiReader: - apply(cluster: Cluster[SocketAddress], queueName: String) - apply(clients: Seq[Client], queueName: String) - apply(handles: ju.Iterator[ReadHandle]) - newBuilder(cluster: Cluster[SocketAddress], queueName: String) - merge(readHandleCluster: Cluster[ReadHandle]) Use the c.t.f.Var[Addr]-based apply methods on c.t.f.kestrel.MultiReaderMemcache or c.t.f.kestrel.MultiReaderThriftMux instead. RB_ID=914910

  • finagle-kestrel: Removed from the project. RB_ID=915221

  • finagle-mdns: Removed from the project. RB_ID=915216

  • finagle-memcached: Remove deprecated c.t.f.memcached.BaseClient.cas methods. Use c.t.f.memcached.BaseClient.checkAndSet instead. RB_ID=914678

  • finagle-memcached: c.t.f.memcached.protocol.text.Encoder object is now private. RB_ID=917214

  • finagle-memcached: Make memcached Response subtypes with no fields case objects. RB_ID=917137

  • finagle-mysql: Remove deprecated methods on c.t.f.Mysql:

    • withCredentials; use c.t.f.Mysql.client.withCredentials instead
    • withDatabase; use c.t.f.Mysql.client.withDatabase instead
    • withCharset; use c.t.f.Mysql.client.withCharset instead
    • configured; use c.t.f.Mysql.client.configured instead


  • finagle-native: Removed from the project. RB_ID=915204

  • finagle-netty4: AnyToHeapInboundHandler is gone. Use BufCodec while designing new Finagle protocols. RB_ID=915251

  • finagle-ostrich4: Removed from the project. RB_ID=915327

  • finagle-redis: ChannelBuffer methods and converters are removed. Use Buf-based API instead. Removed APIs: RB_ID=916015

    • c.t.f.redis.NettyConverters
    • c.t.f.redis.util.StringToChannelBuffer
  • finagle-stream: Removed from the project. RB_ID=915200

  • finagle-thrift: Remove deprecated c.t.f.thrift.transport.netty3.ThriftServerBufferedCodec and c.t.f.thrift.transport.netty3.ThriftServerBufferedCodecFactory. Use the c.t.f.Thrift object to build a server. RB_ID=915656

  • finagle-thriftmux: Remove deprecated c.t.f.ThrifMux.withClientId. Use c.t.f.ThriftMux.client.withClientId. Remove deprecated c.t.f.ThrifMux.withProtocolFactory. Use c.t.f.ThriftMux.client.withProtocolFactory. RB_ID=915655


New Features

  • finagle-thriftmux: Allow ThriftMux.Servers to be filtered, also add withStack method to server side as well. RB_ID=915095
  • finagle-core: FailureAccrual is now production ready. It has been promoted out of experimental and moved from com.twitter.finagle.service.exp to com.twitter.finagle.liveness. RB_ID=914662
  • finagle-core: SSL/TLS APIs have been changed to include methods which work based on an SSL configuration, and an SSL configuration and an SSL engine factory. RB_ID=911209
  • finagle-core: LoadBalancerFactory now exposes a mechanism to order the collection of endpoints passed to the balancer implementations. This allows a consistent ordering of endpoints across process boundaries. RB_ID=910372
  • finagle-core: Introduce c.t.f.client.EndpointerStackClient, a mechanism for making clients that don’t need a transporter and dispatcher. This simplifies making non-netty clients. RB_ID=912889
  • finagle-http2: Add support for liveness detection via pings. It can be configured the same way as it is in mux. RB_ID=913341
  • finagle-toggle: Standard toggles now track the last value produced from apply. These values are visible via TwitterServer’s /admin/toggles endpoint. RB_ID=913925

Breaking API Changes

  • finagle-mysql: Support for Netty 3 has been removed, making Netty 4 the only transport implementation. RB_ID=914661

  • finagle-core: com.twitter.finagle.service.exp.FailureAccrualPolicy has been promoted to com.twitter.finagle.liveness.FailureAccrualPolicy

  • finagle-commons-stats: Remove finagle-commons-stats, which was a compatibility layer for a deprecated stats library. Please move to finagle-stats instead. RB_ID=910964

  • finagle-core: SSL/TLS stack params for Finagle running Netty 4 have changed.

    • The TlsConfig param in Transport has been removed.
    • For client engines, the same two parameters as Finagle running Netty 3 are now used:
      • ClientSsl in Transport, which is used for configuring a client Engine’s hostname, key credentials, trust credentials, cipher suites, protocols, and application protocols.
      • SslClientEngineFactory in SslClientEngineFactory, which determines how the Engine is created based off of an Address and an SslClientConfiguration.
    • For server engines, the same two parameters as Finagle running Netty 3 are now used:
      • ServerSsl in Transport, which is used for configuring a server Engine’s key credentials, trust credentials, cipher suites, protocols, application protocols, and where the server supports or requires client authentication.
      • SslServerEngineFactory in SslServerEngineFactory, which determines how the Engine is created based off of an SslServerConfiguration.
    • Note: Not all client and server configurations work with all engine factories. Each engine factory should document what is not supported by that specific engine factory.
    • Note: By default, Finagle on Netty 4 will use the Netty4ClientEngineFactory and Netty4ServerEngineFactory respectively.


  • finagle-core: Change the API to LoadBalancerFactory to a more concrete Activity[IndexedSeq[ServiceFactory[Req, Rep]]] since the majority of the load balancer implementations don’t need the properties of a Set but instead need ordering guarantees and efficient random access. RB_ID=910372

  • finagle-core: Balancers.aperture now has a new parameter useDeterministicOrdering, which is set to false by default. This feature is still experimental and under construction. This will break the Java API and require the additional param to be passed in explicitly. RB_ID=911541

  • finagle-core: The logic for tracking sessions that was in StdStackServer has been lifted into a new template, ListeningStackServer where implementations define the creation of a ListeningServer from a ServiceFactory, SocketAddress, and a function that tracks accepted sessions. RB_ID=914124

  • finagle-core: Change the AddressOrdering param to no longer take a StatsReceiver, since orderings were simplified and are no longer composite. RB_ID=914113

  • finagle-core: Remove deprecated methods on c.t.f.Client:

    • newClient(dest: Group[SocketAddress])
    • newService(dest: Group[SocketAddress])


  • finagle-core: c.t.f.ListeningServer no longer extends c.t.f.Group. Use c.t.f.ListeningServer.boundAddress to extract the address from the server. RB_ID=914693

  • finagle-core: Remove deprecated Use c.t.f.addr.StabilizingAddr instead. RB_ID=914823

  • finagle-core: Constructors for c.t.f.ChannelException and its subclasses now have overloads that take Options instead of allowing null. While the existing constructors remain, and forward to the new ones, this can still cause compilation failures when the arguments are ambiguous. RB_ID=914800

  • finagle-core: Remove MimimumSetCluster since it has been deperecated for quite some time. Instead, use finagle logical destinations via Name`s. ``RB_ID=914849`

  • finagle-core: Remove deprecated c.t.f.Resolver.resolve. Use c.t.f.Resolver.bind instead. Remove deprecated c.t.f.BaseResolver.resolve. Use c.t.f.Resolver.eval instead. RB_ID=914986

  • finagle-http: c.t.f.http.Http codec has disappeared as part of Netty 4 migration. Use c.t.f.Http.client or c.t.f.Http.server stacks instead. RB_ID=912427

  • finagle-kestrel: Remove c.t.f.kestrel.param.KestrelImpl. Kestrel clients and servers now use Netty 4 and cannot be configured for Netty 3. RB_ID=911031

  • finagle-memcached: Remove c.t.f.memcached.param.MemcachedImpl. Memcached clients and servers now use Netty 4 and cannot be configured for Netty 3. RB_ID=911031

  • finagle-kestrel: Remove commands that are not supported by the client:

    • com.twitter.finagle.kestrel.protocol.DumpConfig
    • com.twitter.finagle.kestrel.protocol.DumpStats
    • com.twitter.finagle.kestrel.protocol.FlushAll
    • com.twitter.finagle.kestrel.protocol.Reload
    • com.twitter.finagle.kestrel.protocol.ShutDown
    • com.twitter.finagle.kestrel.protocol.Stats
    • com.twitter.finagle.kestrel.protocol.Version


  • finagle-memcached: Remove deprecated c.t.f.memcached.KetamaClientBuilder. Use c.t.f.Memcached.client to create a Memcached client. RB_ID=907352

  • finagle-memcached: Remove deprecated c.t.f.memcached.replication.ReplicationClient. Use c.t.f.memcached.replication.BaseReplicationClient with clients created using c.t.f.Memcached.client. RB_ID=907352

  • finagle-memcached: Remove deprecated methods on c.t.f.memcached.Client: - apply(name: Name) - apply(host: String)

    Use c.t.f.Memcached.client to create a Memcached client. RB_ID=908442

  • finagle-memcached: Remove deprecated c.t.f.memcached.protocol.text.Memcached object. Use c.t.f.Memcached.client to create Memcached clients. RB_ID=908442

  • finagle-memcached: Remove deprecated c.t.f.memcached.Server class. Use c.t.f.memcached.integration.TestMemcachedServer for a quick test server. RB_ID=914827

  • Remove deprecated c.t.f.memcached.PartitionedClient object. Use c.t.f.memcached.CacheNodeGroup.apply instead of c.t.f.memcached.PartitionedClient.parseHostWeights. RB_ID=914827

  • Remove deprecated c.t.f.memcached.util.ParserUtils.DIGITS. Use “^\d+$” instead. Remove deprecated c.t.f.memcached.util.ParserUtils.DigitsPattern. Use Pattern.compile(^\d+$) instead. RB_ID=914827

  • finagle-memcached: Remove old c.t.f.memcached.replicated.BaseReplicationClient and c.t.f.memcached.migration.MigrationClient, and most c.t.f.memcached.CachePoolCluster methods. RB_ID=910986

  • finagle-memcached: Remove old c.t.f.memcached.migration.DarkRead, and c.t.f.memcached.migration.DarkWrite. RB_ID=911367

  • finagle-memcached: Remove c.t.f.memcached.CachePoolConfig. RB_ID=914623

  • finagle-mux: Netty 3 implementation of Mux is removed. Default is Netty 4. RB_ID=914239

  • finagle-netty4: DirectToHeapInboundHandler was renamed to AnyToHeapInboundHandler and now copies any inbound buffer (not just directs) on heap. RB_ID=913984

  • finagle-thrift, finagle-thriftmux: Remove rich client/server support for prior versions of Scrooge generated code. RB_ID=911515

  • finagle-core: c.t.f.client.Transporter no longer has a close method, which was introduced in 6.43.0. It was sort of a hack, and we saw the opportunity to do it properly. RB_ID=912889

  • finagle-core, finagle-mux: Move FailureDetector from c.t.f.mux to c.t.f.liveness. This also means that the sessionFailureDetector flag is now c.t.f.liveness.sessionFailureDetector. RB_ID=912337

Bug Fixes

  • finagle-exp: DarkTrafficFilter now respects the log level when HasLogLevel, and otherwise defaults the level to warning instead of error. RB_ID=914805
  • finagle-netty4: Fixed connection stall on unsuccessful proxy handshakes in Finagle clients configured with HTTP proxy (Transporter.HttpProxyTo). RB_ID=913358

Runtime Behavior Changes

  • finagle-netty4: Finagle is no longer logging the failed proxy handshake response. RB_ID=913358
  • finagle-netty4: SOCKS5 proxies are now bypassed if the connect destination is localhost. This matches Finagle’s prior behavior from when Netty 3 was the default transport implementation. RB_ID=914494


  • finagle-memcached: Remove dependency on com.twitter.common:io-json. RB_ID=914623


New Features

  • finagle-base-http: c.t.f.http.Message now has a Java friendly method to set the HTTP version: Message.version(Version). RB_ID=906946
  • finagle-base-http: Added Java friendly methods to the HTTP model including c.t.f.http.Message.contentLength(Long), c.t.f.http.Message.contentLengthOrElse(Long): Long, and c.t.f.http.Request.method(Method). RB_ID=907501
  • finagle-base-http: c.t.f.http.HeaderMap now has a method, HeaderMap.newHeaderMap for creating new empty HeaderMap instances. RB_ID=907397
  • finagle-core: SSL/TLS client and server configurations and engine factories have been added for finer grained control when using TLS with Finagle. RB_ID=907191
  • finagle-netty4: Introducing a new toggle com.twitter.finagle.netty4.UsePooling that enables byte buffers pooling in Netty 4 pipelines. RB_ID=912789

Breaking API Changes

  • finagle-base-http: c.t.f.http.MapHeaderMap has been made private. Please use HeaderMap.apply or HeaderMap.newHeaderMap to construct a new HeaderMap instance. RB_ID=907397

  • finagle-base-http: c.t.f.http.Version is no longer represented by case objects and has been replaced by val instances of a case class. RB_ID=906946

  • finagle-base-http: The common HTTP methods are no longer modeled by case objects but as instances of a single c.t.f.http.Method class. The string representation of the HTTP method is now available via the method. RB_ID=906697

  • finagle-core: Move the argument from the apply method on com.twitter.finagle.client.Transporter to the newTransporter method of com.twitter.finagle.client.StackClient. RB_ID=907544

  • finagle-core: Load Balancer implementations no longer mix-in the OnReady trait and OnReady was removed. RB_ID=908863

  • finagle-core: HeapBalancer, ApertureLoadBalancer, and RoundRobinBalancer classes were made package private. To construct load balancers for use within a Finagle client, use the com.twitter.finagle.loadbalancer.Balancers object. RB_ID=909245

  • finagle-core: The aperture constructor on the Balancers object no longer takes a Timer since it was unused. RB_ID=909245

  • finagle-core: The load balancer algorithm is now further scoped under “algorithm”. RB_ID=909309

  • finagle-core: Remove Ring from Finagle core’s util since it is unused internally. RB_ID=909718

  • finagle-core: SSL/TLS stack params for Finagle running Netty 3 have changed.

    • The TLSClientEngine param in Transport has been replaced by two parameters:
      • ClientSsl in Transport, which is used for configuring a client Engine’s hostname, key credentials, trust credentials, cipher suites, protocols, and application protocols.
      • SslClientEngineFactory in SslClientEngineFactory, which determines how the Engine is created based off of an Address and an SslClientConfiguration.
    • The TLSHostname param in Transporter has been removed. Hostnames should be set as part of the SslClientConfiguration now.
    • The TLSServerEngine param in Transport has been replaced by two parameters:
      • ServerSsl in Transport, which is used for configuring a server Engine’s key credentials, trust credentials, cipher suites, protocols, application protocols, and whether the server supports or requires client authentication.
      • SslServerEngineFactory in SslServerEngineFactory, which determines how the Engine is created based off of an SslServerConfiguration.
    • Note: Not all client and server configurations work with all engine factories. Each engine factory should document what is not supported by that specific engine factory.
    • Note: Users using Finagle-Native should in the short term use LegacyServerEngineFactory and in the long term move to using Netty4ServerEngineFactory.
    • Note: With this change, private keys are expected to explicitly be PKCS#8 PEM-encoded keys. Users using PKCS#1 keys should in the short term use LegacyKeyServerEngineFactory and in the longer term switch to using PKCS#8 keys, or use your own SslServerEngineFactory which can explicitly handle those type of keys.
    • Note: By default, Finagle on Netty 3 will use the JdkClientEngineFactory and JdkServerEngineFactory respectively.


  • finagle-core: withLoadBalancer.connectionsPerEndpoint was removed and moved into finagle-memcached, which was the only client that uses the feature. RB_ID=908354

  • finagle-core: ClientBuilder.expHttpProxy and ClientBuilder.expSocksProxy are removed. Use $Protocol.withTransport.httpProxyTo instead (requires Netty 4 transport). RB_ID=909739

  • finagle-kestrel: Remove the deprecated codec method on c.t.f.kestrel.MultiReaderMemcache. Use .stack(Kestrel.client) on the configured c.t.f.builder.ClientBuilder instead. RB_ID=907184

  • finagle-kestrel: Removed c.t.f.kestrel.Server. A local Kestrel server is preferred for testing. RB_ID=907334

  • finagle-kestrel: Removed deprecated c.t.f.kestrel.protocol.Kestrel. To create a Finagle Kestrel client, use c.t.f.Kestrel.client. RB_ID=907422

  • finagle-serversets: Removed the unapply method and modified the signature of fromAddrMetadata method in c.t.f.serverset2.addr.ZkMetadata. Instead of pattern matching use the modified fromAddrMetadata method. RB_ID=908186

  • finagle-stats: Remove the com.twitter.finagle.stats.exportEmptyHistograms toggle which has defaulted to 0.0 for quite some time. Change the default value of the com.twitter.finagle.stats.includeEmptyHistograms flag to false to retain the behavior. RB_ID=907186

  • finagle-thrift: ThriftServiceIface was refactored to be in terms of ThriftMethod.Args to ThriftMethod.SuccessType instead of ThriftMethod.Args to ThriftMethod.Result. RB_ID=908846

  • finagle-redis: Remove pendingCommands from c.t.f.finagle.redis.SentinelClient.Node and add linkPendingCommands for compatibility with redis 3.2 and newer. RB_ID=913516

Runtime Behavior Changes

  • finagle-http: Responses with a server error status code (500s) are now classified as a failure. This effects success rate metrics and failure accrual. See the com.twitter.finagle.http.serverErrorsAsFailuresV2 toggle for opting out of this behavior. RB_ID=909315
  • finagle-netty4: Servers no longer set SO_LINGER=0 on sockets. RB_ID=907325


  • finagle-base-http: The c.t.f.http.Response methods getStatusCode() and setStatusCode() have been deprecated. Use the methods statusCode and statusCode(Int) instead. RB_ID=908409
  • finagle-core: and c.t.f.builder.ClientBuilder.cluster have been deprecated. Use c.t.f.builder.ClientBuilder.dest with a c.t.f.Name instead. RB_ID=914879
  • finagle-http: Now that c.t.f.http.Method and c.t.f.http.Version are represented by instances and thus easier to use from Java, the Java helpers c.t.f.http.Versions, c.t.f.http.Statuses, and c.t.f.http.Methods have been deprecated. RB_ID=907680
  • finagle-memcached: c.t.f.memcached.replication.ReplicationClient is now deprecated. Use c.t.f.memcached.replication.BaseReplicationClient with clients created using c.t.f.Memcached.client. RB_ID=907384
  • finagle-thrift: As part of the Netty 4 migration, all c.t.f.Codec and c.t.f.CodecFactory types in finagle-thrift are now deprecated. Use the c.t.f.Thrift object to make clients and servers. RB_ID=907626

Bug Fixes

  • finagle-core: Fix ConcurrentModificationException thrown by calling close() on c.t.f.factory.ServiceFactoryCache. RB_ID=910407
  • finagle-http: The HTTP/1.x Client will no longer force-close the socket after receiving a response that lacks content-length and transfer-encoding headers but is required per RFC 7230 to not have a body. RB_ID=908593
  • finagle-redis: The HSCAN and SCAN commands take an optional argument for pattern matching. This argument has been fixed to use the correct name of ‘MATCH’ instead of the incorrect ‘PATTERN’. RB_ID=908817
  • finagle-thrift: Properly locate sub-classed MethodIface services to instantiate for serving BaseServiceIface implemented thrift services. RB_ID=907608
  • finagle-redis: The SentinelClient will no longer throw an NoSuchElementException when initializing connections to a redis 3.2 or greater sentinel server. RB_ID=913516


  • finagle: Bump guava to 19.0. RB_ID=907807


New Features

  • finagle-commons-stats: Provide a TwitterServer exporter for commons stats. This simplifies migration for folks who don’t want to switch to commons metrics and TwitterServer in one go. It will export stats on the /vars.json endpoint. RB_ID=902921
  • finagle-http: Introduce HeaderMap.getOrNull(header), a Java-friendly variant of HeaderMap.get(header).orNull. RB_ID=904093

Breaking API Changes

  • finagle: finagle-http-compat has been removed as part of migration off Netty 3. Use finagle-http types/APIs directly. RB_ID=903647

  • finagle: finagle-spdy has been removed as part of the migration off Netty 3. Please use finagle-http2 as a replacement. RB_ID=906033

  • finagle-base-http: Message.write(ChannelBuffer) has been replaced with a method that receives a Buf. The semantics of calling the write method on chunked messages has changed from potentially throwing an exception based on the state of the Writer to always throwing an IllegalStateException. Existing users of the write(..) methods on chunked messages should use the Writer directly. RB_ID=900091

  • fingle-base-http: HeaderMap.getAll(key) now returns a Seq[String] as opposed to a Iterable[String]. RB_ID=905019

  • finagle-core: The ChannelTransport implementations which transforms a Netty pipeline into a finagle Transport[Req, Rep] have been specialized to Transport[Any, Any] to avoid the illusion of a runtime checked cast. Transport.cast has been changed to receive either a Class[T] or an implicit Manifest[T] in order to check the inbound cast at runtime. For users of the ChannelTransport types, use the Transport.cast method to get a Transport of the right type. RB_ID=902053

  • finagle-memcached: Remove deprecated methods on c.t.f.memcached.Client:
    • apply(group: Group[SocketAddress])
    • apply(cluster: Cluster[SocketAddress])

    Use c.t.f.Memcached.client to create a Memcached client. RB_ID=899331

  • finagle-toggle: ToggleMap Toggles now rehash the inputs to apply and isDefinedAt in order to promote a relatively even distribution even when the inputs do not have a good distribution. This allows users to get away with using a poor hashing function such as String.hashCode. RB_ID=899195


  • finagle-base-http: Deprecate c.t.f.http.MapHeaderMap as it will soon be private. Use c.t.f.http.HeaderMap.apply(..) to get a HeaderMap instance. RB_ID=906497

  • finagle-base-http: Deprecate c.t.f.http.HeaderMap += (String, Date). Use c.t.f.http.HeaderMap.set(String, Date) instead. RB_ID=906497

  • finagle-base-http: Deprecate c.t.f.http.Message.ContentTypeWwwFrom. Use c.t.f.http.Message.ContentTypeWwwForm instead. RB_ID=901041

  • finagle-base-http: Deprecate c.t.f.http.Message.headers(). Use c.t.f.http.Message.headerMap instead. RB_ID=905019

  • finagle-base-http: Deprecate the lazy response: Response field on the Request type. This field is potentially hazardous as it’s not necessarily the Response that will be returned by a Service but it is often used as such. Construct a Response using the static constructor methods. RB_ID=899983

  • finagle-base-http: Numerous protected[finagle] methods on http.Request and http.Response that deal in Netty 3 types have been deprecated as part of the migration to Netty 4. RB_ID=905761

  • finagle-http: Deprecate ValidateRequestFilter which now has limited utility. See entry in Runtime Behavior Changes. If this is still needed, copy the remaining behavior into a new filter. RB_ID=899895

  • finagle-memcached: Deprecate methods on c.t.f.memcached.Client:
    • apply(name: Name)
    • apply(host: String)

    Use c.t.f.Memcached.client to create a Memcached client. RB_ID=899331`

  • finagle-memcached: Deprecate c.t.f.memcached.protocol.text.Memcached object. Use c.t.f.Memcached.client to create Memcached clients. RB_ID=899009

  • finagle-memcached: Deprecations on c.t.f.memcached.util.ParserUtils:
    • For isDigits(ChannelBuffer) use ParserUtils.isDigits(Buf) instead.
    • DIGITS
    • DigitsPattern


Runtime Behavior Changes

  • finagle-http: The HTTP client will no longer emit a Netty 3/4 TooLongFrameException when a response exceeds the specified MaxResponseSize parameter, and instead emits a Finagle specific TooLongMessageException which wraps the Netty exception. RB_ID=905567
  • finagle-http: ValidateRequestFilter doesn’t look for the uri “/bad-http-request” which had been indicative of the netty3 http codec giving up on decoding a http request. These events are caught lower in the pipeline and should not bubble up to the level of this filter. RB_ID=899895
  • finagle-netty4: DirectToHeapHandler is now aware of ByteBufHolder types hence can copy them on to heap. RB_ID=906602
  • finagle-redis: Transport implementation is now based on Netty 4 (instead of Netty 3). RB_ID=895728

Bug Fixes

  • finagle-core: Properly compute length when converting a Buf.ByteArray to a Netty 4 ByteBuf. RB_ID=901605
  • finagle-memcached: AtomicMap change lock function to synchronize on map object. DIFF_ID=D18735
  • finagle-netty4: Fixed connection stall in Finagle clients configured with both HTTP proxy (Transporter.HttpProxyTo) and TLS/SSL enabled. RB_ID=904831
  • finagle-netty4: Fixed connection stall in Finagle clients configured with both HTTP proxy (Transporter.HttpProxy) and TLS/SSL enabled. RB_ID=904803


New Features

  • finagle-core: Added stat “pending_requests/rejected” for the number of requests rejected by c.t.f.PendingRequestFilter. RB_ID=898184

Breaking API Changes

  • finagle-core: Remove the Filter#andThen(Req1 => Future[Rep1]): Req2 => Future[Rep2] method. This overload is no longer usable in scala 2.12, because Service is a SAM. Because of the order in which SAMs get resolved, literal functions in scala will get confused about which method they should use. Instead of passing a Function directly, wrap the Function with a RB_ID=896524
  • finagle-core: CancelledWriteException was removed as it is no longer used. RB_ID=896757
  • finagle-core: The structure of Context and its subtypes, LocalContext and MarshalledContext, have been significantly refined, eliminating StackOverflowErrors and memory leaks while also refining the API. The letClear() method, which cleared all items from the context, has been renamed to letClearAll to avoid confusion with other letClear methods which clear individual keys. The bulk letClear method now takes a collection of Key[_]`s, making it usable from Java. Bulk `let operations can now be done using a collection of KeyValuePair`s. ``RB_ID=896663`
  • finagle-kestrel: The codec method has been removed from the kestrel MultiReader object. Configure a ClientBuilder protocol using the default thrift StackClient, Thrift.client, via the stack method of ClientBuilder. RB_ID=894297
  • finagle-memcached: Remove deprecated cluster method on c.t.f.memcached.KetamaClientBuilder. RB_ID=898365

Runtime Behavior Changes

  • finagle-core: c.t.f.builder.ClientBuilder remove deprecated methods. The same functionality is available through the Stack-based APIs or ClientBuilder.configured, with the exception of channelFactory, which has no analog because it exposes a Netty 3 API. RB_ID=893147

    • channelFactory
    • expHostConnectionBufferSize
    • hostConnectionIdleTime
    • hostConnectionMaxIdleTime
    • hostConnectionMaxLifeTime
    • hostConnectionMaxWaiters
    • readerIdleTimeout
    • recvBufferSize
    • sendBufferSize
    • writerIdleTimeout
  • finagle-core: Lower logging level used in c.t.f.util.DefaultMonitor for expected exceptions: CancelledRequestException, TooManyWaitersException, CancelledConnectionException, FailedFastException. RB_ID=895702

  • finagle-core: c.t.f.util.DefaultMonitor now logs most exceptions at WARNING level instead of FATAL. RB_ID=895983

  • finagle-core: c.t.f.util.DefaultMonitor works harder to find the appropriate log level by walking the exception’s causes to find c.t.util.TimeoutExceptions and c.t.logging.HasLogLevel. RB_ID=896695

  • finagle-core: The c.t.f.service.Retries module will now flag a response as NonRetryable if either the retry limit is reached or the retry budget is exhausted. RB_ID=897800

  • finagle-mdns: Uses only one implementation backed by jmdns instead of trying to use a platform specific implementation of DDNS if present. RB_ID=897917

  • finagle-netty4: Client initiated TLS/SSL session renegotiations are now rejected by default. RB_ID=895871

  • finagle-netty4: ChannelTransport no longer interrupts netty write operations in order to temporarily unblock rollout of netty4. This reverts netty4 back to netty3 semantics for writes. RB_ID=896757


  • finagle-kestrel: Deprecate the codec method on c.t.f.kestrel.MultiReaderMemcache. Use .stack(Kestrel.client) on the configured c.t.f.builder.ClientBuilder instead. RB_ID=895989


New Features

  • finagle: Most libraries (excluding finagle-thrift{,mux}) no longer need to add an additional resolver that points to RB_ID=878967
  • finagle: Introducing a new Finagle module finagle-base-http that provides a common ground for both Netty 3 (finagle-http) and Netty 4 (finagle-netty4-http) HTTP implementations. Netty 3 is still a default transport used in Finagle’s Http.client and Http.server. `RB_ID=884614
  • finagle-core: Introduce the c.t.f.client.DynamicTimeout module allowing clients to specify call-site specific timeouts. RB_ID=885005
  • finagle-core: A new module, c.t.f.service.DeadlineFilter, can be added to stack-based servers and clients, which rejects requests with expired deadlines RB_ID=895820
  • finagle-memcached: Introduce c.t.f.memcached.CasResult.replaced: Boolean to help transition usage off of the deprecated cas client method to checkAndSet. RB_ID=891628
  • finagle-thrift: We now depend on a fork of libthrift hosted in the Central Repository. The new package lives in the ‘com.twitter’ organization. This removes the necessity of depending on This also means that eviction will not be automatic and using a newer libthrift library requires manual eviction if artifacts are being pulled in transitively. RB_ID=885879

Runtime Behavior Changes

  • finagle-core: Monitor logging is improved in Finagle. RB_ID=878890
    • All exceptions caught in the stack are now logged by Finagle’s DefaultMonitor (previously Util’s RootMonitor) such that Twitter’s logging framework is used instead of JDK logging.
    • DefaultMonitor is now installed implicitly such that it will be composed (via orElse) with the monitor passed by a user through the stack param. The logic behind this compostion is quite straightforward: exceptions that are’t handled by a user-defined monitor propagated to the default monitor.
    • DefaultMonitor now logs upstream socket address, downstream socket address, and a client/server label if those are available.
    • RootMonitor is still used to handle fatal exceptions from pending side-effect-only closures (i.e., onFailure, onSuccess) on a service future/promise.
  • finagle-core: c.t.f.service.DeadlineStatsFilter has been removed from the server stack, along with all related stats. The “admission_control/deadline/transit_latency_ms” stat has been moved to c.t.f.filter.ServerStatsFilter and re-scoped as “transit_latency_ms” RB_ID=895820
  • finagle-mux: com.twitter.finagle.Failures are now sent over the wire with their flags intact via com.twitter.finagle.mux.transport.MuxFailure in the previously unused Rdispatch context. This allows for greater signaling along a chain of services. See the “MuxFailure Flags” section of the mux protocol spec in finagle-mux/src/main/scala/c/t/f/mux/package.scala RB_ID=882431
  • finagle-netty4: The netty4 listener + transporter no longer manage direct byte buffers by default. is introduced to help protocol builders manage them. RB_ID=881648
  • finagle-stats: Changed the default behavior of empty histograms to only export the count. Thus the com.twitter.finagle.stats.exportEmptyHistograms toggle now defaults to 0.0. RB_ID=882522

Breaking API Changes

  • finagle: Some APIs around configuring TLS/SSL on Finagle clients have changed to unblock Netty 4 adoption. RB_ID=890935
    • c.t.f.Http.client.withTls(Netty3TransporterTLSConfig) is removed. Use variations of c.t.f.Http.client.withTransport.tls instead.
    • c.t.f.netty3.Netty3TransporterTLSConfig is removed.
  • finagle: Some APIs around configuring TLS/SSL on Finagle servers have changed to unblock Netty 4 adoption. RB_ID=891270
    • c.t.f.Http.server.withTls(Netty3ListenerTLSConfig) is removed. Use variations of c.t.f.Http.server.withTransport.tls instead.
    • c.t.f.netty3.Netty3ListenerTLSConfig is removed.
  • finagle-core: Removed the protected and unused method read(permit: Permit): Future[Rep] from SerialClientDispatcher. RB_ID=881978
  • finagle-core: Removed a gauge, idle, from c.t.f.factory.ServiceFactoryCache. RB_ID=884210
  • finagle-core: ServiceTimeoutException now extends NoStackTrace. RB_ID=886809
  • finagle-core: Marked com.twitter.finagle.util.ConcurrentRingBuffer as private. It doesn’t fit the typical programming model we encourage for users of finagle, and so we found it was rarely used. RB_ID=888801
  • finagle-core: Marked transform in com.twitter.finagle.Stack as protected. It is too powerful and unnecessary for users, and should be used by implementors only.
  • finagle-core: Removed the StatsReceiver argument from TimeoutFilter. RB_ID=891380
  • finagle-core: Stopped exporting a few metrics related to deadlines, and replaced with a simpler one. There was a per-TimeoutFilter one named timeout/expired_deadline_ms, and a per-server one named admission_control/deadline/deadline_budget_ms. We added instead a per-server one named admission_control/deadline/exceeded_ms. RB_ID=891380
  • finagle-http: HttpMuxer now takes in a Seq[Route] instead of a Seq[(String, Service[Request, Response])]. RB_ID=886829
  • finagle-http: As part of the first step towards restructuring Finagle HTTP modules required for Netty 4 adoption, HTTP params are moved from the inner object c.t.f.Http.param into their own package c.t.f.http.param. RB_ID=885155
  • finagle-redis: A couple of methods had to be renamed (and return type changed) to unblock Netty 4 adoption. RB_ID=882622
    • Command.toChannelBuffer renamed to Command.toBuf and return type changed from N3 ChannelBuffer to Finagle Buf.
    • Command.toByteArray is removed.
    • Both Command.key and Command.value now implemented in terms of Buf`s (no `ChannelBuffers).
  • finagle-redis: An API around c.t.f.redis.protocol.Command was modernized as part of major restructuring required for the Netty 4 adoption. RB_ID=885811
    • RedisMessage (a common parent for both Command and Reply) has been removed.
    • The encoding machinery was restructured to eliminate duplicated and dead code.
  • finagle-thrift: Removed deprecated ThriftRichClient.newServiceIface methods which did not take a label. Use the versions that take a String label. RB_ID=891004
  • finagle-thrift: Removed deprecated ThriftRichClient.newIface methods based on Groups. Use the versions that a dest or Name. RB_ID=891004
  • finagle-thriftmux: Removed deprecated classes ThriftMuxClient, ThriftMuxClientLike, ThriftMuxServer, and ThriftMuxServerLike. RB_ID=880924

Bug Fixes

  • finagle-core: The withTlsWithoutValidation and tlsWithoutValidation APIs have been fixed for an issue on Java 8 where certificate validation was being attempted instead of bypassed. RB_ID=881660
  • finagle-http: The toggle implementation for com.twitter.finagle.http.serverErrorsAsFailures had a bug when toggled on. That toggle is no longer used and is superseded by com.twitter.finagle.http.serverErrorsAsFailuresV2. RB_ID=882151
  • finagle-netty4: Connecting to a Socks 5 proxy using Finagle with Netty 4 now works properly. This previously resulted in a timeout and ProxyConnectException. RB_ID=884344
  • finagle-netty4: Don’t swallow bind failures. RB_ID=892217


  • finagle-core: c.t.f.builder.ClientBuilder deprecate some seldom used methods. The same functionality is available through the Stack-based APIs or ClientBuilder.configured. RB_ID=881612

    • hostConnectionIdleTime
    • hostConnectionMaxIdleTime
    • hostConnectionMaxLifeTime
    • hostConnectionMaxWaiters


New Features

  • finagle-core: com.twitter.finagle.Failure has a new flag, NonRetryable, which signifies that a request should not be retried. The flag is respected by all of Finagle’s retry mechanisms. RB_ID=878766
  • finagle-thriftmux: Allow ThriftMux.Clients to be filtered. This is supported in the the StdStackClient but ThriftMux.Client is a StackBasedClient. RB_ID=874560
  • finagle-netty4: Add boolean flag com.twitter.finagle.netty4.poolReceiveBuffers that enables/disables pooling of receive buffers (disabled by default). When enabled, lowers the CPU usage and allocation rate (GC pressure) with the cost of increased memory footprint at the startup. RB_ID=872940
  • finagle-netty4: Add new histogram receive_buffer_bytes (only enabled with pooling) to keep track of the receive buffer sizes (useful for tuning pooling). RB_ID=877080


  • finagle-core: c.t.f.builder.ClientBuilder deprecate some seldom used methods. The same functionality is available through the Stack-based APIs or ClientBuilder.configured. RB_ID=878009
    • readerIdleTimeout
    • writerIdleTimeout
    • recvBufferSize
    • sendBufferSize
    • channelFactory
    • expHostConnectionBufferSize
  • finagle-kestrel: Deprecate c.t.f.kestrel.protocol.Kestrel(), c.t.f.kestrel.protocol.Kestrel(failFast), and c.t.f.kestrel.protocol.Kestrel.get(). To create a Kestrel client using ClientBuilder, use .stack(c.t.f.Kestrel.client). RB_ID=870686

Breaking API Changes

  • finagle-core: The constructors for both c.t.f.netty3.Netty3Listener and c.t.f.netty3.Netty3Transporter now take Stack.Params instead of individual parameters. RB_ID=871251
  • finagle-thrift: The c.t.f.thrift.legacy package has been removed which included the public types ThriftCall, ThriftReply, and ThriftCallFactory. RB_ID=873982

Runtime Behavior Changes

  • finagle-core: Tolerate TraceIds that are greater than 64 bits in preparation of moving to 128 bit ids. RB_ID=874365
  • finagle-http: c.t.f.http.service.HttpResponseClassifier.ServerErrorsAsFailures now classifies a retryable nack as a ResponseClass.RetryableFailure. RB_ID=869182
  • finagle-http: c.t.f.Http.{Client,Server} is moving towards treating HTTP 5xx status codes as failures via c.t.f.http.service.HttpResponseClassifier.ServerErrorsAsFailures. This can be disabled by setting the toggle “com.twitter.finagle.http.serverErrorsAsFailures” to 0.0 or explicitly setting it using withResponseClassifier. RB_ID=869303, RB_ID=875367
  • finagle-http: c.t.f.http.HttpServerDispatcher now removes the bodies from responses to HEAD requests in order to avoid a HTTP protocol error and logs the event at level error. Associated with this, the c.t.f.http.filter.HeadFilter will now strip the body from a chunked response, but in these cases the Writer associated with the response will receive a ReaderDiscarded exception if a write is attempted after the filter has run. RB_ID=872106
  • finagle-thrift: Also track response failures in the c.t.finagle.thrift.ThriftServiceIface#statsFilter in addition to successful responses that encode an Error or Exception. RB_ID=879075

Bug Fixes

  • finagle-http: Fix issue in c.t.finagle.http.RequestBuilder when the URI host contains underscores. RB_ID=870978
  • finagle-http: A connection for HTTP/1.0 or non-keep-alive requests is now closed gracefully so that all requests that have been issued received responses. RB_ID=868767
  • finagle-http: The HTTP/1.x server dispatcher no longer clobbers ‘Connection: close’ headers set by a service, resulting in the graceful shutdown of the connection. RB_ID=880007
  • finagle-netty4: ChannelTransport now drains messages before reading more data off the transport which should reduce memory pressure in streaming protocols. RB_ID=872639


New Features

  • finagle-http: HttpNackFilter now handles both retryable and non-retryable nacks via a new header: “finagle-http-nonretryable-nack”. These are converted to non-retryable c.t.f.Failures and counted by a new counter “nonretryable_nacks”. RB_ID=865468
  • finagle-toggle: Is no longer considered experimental. RB_ID=868819

Breaking API Changes

  • finagle-kestrel: c.t.f.kestrel.protocol.ResponseToEncoding is now private[finagle]. RB_ID=866612
  • finagle-memcached: c.t.f.memcached.protocol.text.{CommandToEncoding, ResponseToEncoding}, c.t.f.memcached.protocol.text.client.{AbstractDecodingToResponse, ClientTransport, DecodingToResponse} are now private[finagle]. RB_ID=866612
  • finagle-netty4: Move numWorkers flag out of the package object so it gets a user friendly name: c.t.f.netty4.numWorkers instead of c.t.f.netty4$.package$.numWorkers. RB_ID=123567
  • finagle-core: c.t.f.netty3.WorkerPool is no longer visible outside of c.t.f.netty3. RB_ID=123567
  • finagle-core: The content parameter of the ClientSslContext and ClientSslContextAndHostname TlsConfig options has been renamed to context. RB_ID=868791

Runtime Behavior Changes

  • finagle-thriftmux: Removed “<server_label>/thriftmux/downgraded_connections” and “<server_label>/thriftmux/connections” gauges. Counters are still available at “<server_label>/thrifmux/connects” and “<server_label>thriftmux/downgraded_connects”. RB_ID=867459



  • finagle-core: c.t.f.Deadline is deprecated in favor of c.t.f.context.Deadline. RB_ID=864148

Breaking API Changes

  • finagle-core: As part of a move away from encoding/decoding in the Netty pipeline, removed FrameEncoder and FrameDecoder types, found in c.t.f.codec. RB_ID=847716

  • finagle-core: Delete IdleConnectionFilter, which is no longer hooked up in the server, and no longer seems to be useful. RB_ID=856377

  • finagle-core: Remove deprecated methods from c.t.f.builder.ClientBuilder RB_ID=864622

    • connectionTimeout, use tcpConnectTimeout
    • expFailFast, use failFast
    • buildFactory, use other buildFactory methods
    • build, use other build methods
  • finagle-exp: Abstract out parts of the DarkTrafficFilter for potential re-use. We also canonicalize the DarkTrafficFilter stats scope which changes from “darkTrafficFilter” to “dark_traffic_filter”. E.g.: “dark_traffic_filter/forwarded”, “dark_traffic_filter/skipped”, and “dark_traffic_filter/failed”. RB_ID=852548

  • finagle-mysql: Mysql has been promoted out of experimental. Please change all references of com.twitter.finagle.exp.{M,m}ysql to com.twitter.finagle.{M,m}ysql

  • finagle-redis: Server-side support for Redis is removed. See this finaglers@ thread (!topic/finaglers/dCyt60TJ7eM) for discussion. Note that constructors for Redis commands no longer accept raw byte arrays. RB_ID=848815

  • finagle-redis: Redis codec (i.e., c.t.f.Codec) is removed. Use c.t.f.Redis.client instead. RB_ID=848815

New Features

  • finagle-core: Expose metrics on util’s default FuturePool implementations unboundedPool and interruptibleUnboundedPool: “finagle/future_pool/pool_size”, “finagle/future_pool/queue_size”, “finagle/future_pool/active_tasks”, and “finagle/future_pool/completed_tasks”. RB_ID=850652
  • finagle-core: Mux Clients now propagate the number of times the client retried the request in the request’s c.t.f.context.Context, available via c.t.f.context.Retries. RB_ID=862640
  • finagle-http: HTTP Clients now propagate the number of times the client retried the request in the request’s c.t.f.context.Context, available via c.t.f.context.Retries. RB_ID=864852
  • finagle-thrift: maxThriftBufferSize is now tunable via parameter for Thrift servers. It previously only was for ThriftMux servers. RB_ID=860102

Runtime Behavior Changes

  • finagle-http: HttpTransport now eagerly closes client connection after processing non-keepalive requests.
  • finagle-redis: c.t.f.redis.Client now uses the pipelining dispatcher. RB_ID=848815
  • finagle-serversets: c.t.f.serverset2.Stabilizer no longer uses a timer to implement stabilization periods if the periods are 0 seconds long. RB_ID=861561
  • finagle-core: ‘c.t.f.Failure’ has a new flag, Rejected, to indicate that a given request was rejected. All Failures generated with the Failure.rejected constructor are flagged Rejected and Restartable. RB_ID=863356
  • finagle-core: c.t.f.FixedInetResolver now optionally retries failed DNS lookups with provided backoff, and c.t.f.serverset2.Zk2Resolver uses this retry functionality infinitely, exponentially backing off from 1 second to 5 minutes. RB_ID=860058



  • finagle-http: Removed DtabFilter.Finagle in favor of DtabFilter.Extractor. RB_ID=840600
  • finagle-zipkin: Deprecate ZipkinTracer in favor of ScribeZipkinTracer. RB_ID=840494

Breaking API Changes

  • finagle: Builds are now only for Java 8 and Scala 2.11. See the blog post for details. RB_ID=828898

  • finagle: Finagle is no longer depending on Twitter’s clone of JSR166e, JDK 8 API is used instead. RB_ID=833652

  • finagle-cacheresolver: package contents merged into finagle-memcached. RB_ID=833602

  • finagle-core: Renamed DeadlineFilter to DeadlineStatsFilter, which now only records stats for the number of requests with exceeded deadlines, the remaining deadline budget, and the transit latency of requests. It no longer rejects requests and has no configuration. We have decided not to pursue Deadline Admission Control at this time. RB_ID=829372

  • finagle-core: ClientBuilder.socksProxy(SocketAddress) is removed. Use command line flags (see c.t.f.socks.SocksProxyFlags.scala) instead. RB_ID=834634

  • finagle-core: Removed “closechans” and “closed” counters from ChannelStatsHandler. RB_ID=835194

  • finagle-core: Removed the “load” gauge from StatsFilter as it was duplicated by the “pending” gauge. RB_ID=835199

  • finagle-core: c.t.finagle.NoStacktrace is removed. Use scala.util.control.NoStackTrace instead. RB_ID=833188

  • finagle-core: c.t.finagle.Failure.withStackTrace is removed. Use system property scala.control.noTraceSuppression instead to fill stacktraces in Finagle’s failures. RB_ID=833188

  • finagle-core: c.t.f.filter.RequestSerializingFilter is removed. Use c.t.f.filter.RequestSemaphoreFilter instead. RB_ID=839372

  • finagle-core: SessionParams no longer contains acquisitionTimeout. Instead, it was extracted into ClientSessionParams. RB_ID=837726

  • finagle-core: Changed visibility of PipeliningDispatcher to private[finagle]. Clients should not be affected, since it’s not a part of the end-user API. RB_ID=843153.

  • finagle-core: Simplified and unified the constructors for FailureAccrualFactory into a single constructor. RB_ID=849660

  • finagle-http: Deprecate channelBufferUsageTracker in favor of maxRequestSize. RB_ID=831233

  • finagle-http: HttpClientDispatcher, HttpServerDispatcher, and ConnectionManager are no longer public. RB_ID=830150

  • finagle-redis: Deprecated methods have been removed from the client API. RB_ID=843455

  • finagle-redis: c.t.f.redis.*Commands traits are now package-private. RB_ID=843455

  • finagle-redis: Replace ChannelBuffer with Buf in client’s:

    • HashCommands: RB_ID=843596
    • ListCommands: RB_ID=844596
    • BtreeSortedSetCommands: RB_ID=844862
    • HyperLogLogCommands: RB_ID=844945
    • PubSubCommands: RB_ID=845087
    • SetCommands: RB_ID=845578
    • SortedSetCommands: RB_ID=846074
  • finagle-thrift: As part of the migration off of Codec, remove c.t.f.thrift.ThriftClientBufferedCodec and c.t.f.thrift.ThriftClientBufferedCodecFactory which were used by ClientBuilder.codec and ServerBuilder.codec. Replace usage with ClientBuilder.stack(Thrift.client.withBufferedTransport) or ServerBuilder.stack(Thrift.server.withBufferedTransport). RB_ID=838146

  • finagle-memcached: c.t.f.memcached.Client now uses c.t.bijection.Bijection instead of c.t.u.Bijection. RB_ID=834383

  • finagle-zipkin: Moved case classes and companion objects Span, ZipkinAnnotation, BinaryAnnotation, Endpoint, Sampler and SamplingTracer to finagle-zipkin-core. RB_ID=840494

  • finagle-mysql: Removed c.t.f.exp.mysql.transport.MysqlTransporter, as it was not useful for it to be public. RB_ID=840718

Bug Fixes

  • finagle-core: PipeliningDispatcher now serializes “write and enqueue Promise” so it’s no longer possible for the wrong response to be given to a request. RB_ID=834927
  • finagle-http: Servers which aggregate content chunks (streaming == false) now return a 413 response for streaming clients who exceed the servers’ configured max request size. RB_ID=828741
  • finagle-mysql: c.t.f.exp.mysql.PreparedCache now closes prepared statements when no one holds a reference to the cached future any longer. This fixes a race condition where the cached future could be evicted and the prepared statement closed while a user tries to use that prepared statement. RB_ID=833970
  • finagle-netty4-http: Servers now see the correct client host address for requests. RB_ID=844076

New Features

  • finagle-core: Added gauge, “scheduler/blocking_ms” measuring how much time, in milliseconds, the com.twitter.concurrent.Scheduler is spending doing blocking operations on threads that have opted into tracking. This also moves the “scheduler/dispatches” gauge out of TwitterServer into Finagle. RB_ID=828289
  • finagle-core: Added a FailureAccrualPolicy that marks an endpoint dead when the success rate in a specified time window is under the required threshold. RB_ID=829984
  • finagle-core: StackServer now installs an ExpiringService module by default. This allows servers to have control over session lifetime and brings the StackServer to feature parity with ServerBuilder. RB_ID=837726
  • finagle-exp: Changed DarkTrafficFilter to forward interrupts to dark service. RB_ID=839286
  • finagle-http: ContextFilter and Dtab-extractor/injector logic has been moved from the http dispatchers into the client and server stacks. RB_ID=840600
  • finagle-mysql: Added a withMaxConcurrentPreparedStatements method to the client which lets you specify how many prepared statements you want to cache at a time. RB_ID=833970
  • finagle-redis: Adds support for scripting commands. RB_ID=837538
  • finagle-netty4: SOCKS5 proxy support. RB_ID=839856
  • finagle-zipkin-core: A new module containing most of the functionality from finagle-zipkin, leaving finagle-zipkin with only Scribe specific code and a service loader. This allows for other transports to be implemented in separate modules. For example the upcoming finagle-zipkin-kafka. RB_ID=840494
  • finagle-thriftmux: Introduce a Netty4 implementation of mux and thrift-mux. RB_ID=842869

Runtime Behavior Changes

  • finagle-core: For SSLEngine implementations supplied via configuration or created by Finagle, the setEnableSessionCreation method is no longer called. The supplied value, true, is the default for JSSE implementations, and for other engines this can be an unsupported operation. RB_ID=845765
  • finagle-core: Pipelined protocols (memcached, redis) no longer prevent connections from being cut by interrupts. Instead, interrupts are masked until a subsequent ten second timeout has expired without a response in the pipeline. RB_ID=843153
  • finagle-core: MonitorFilter now installs the parameterized monitor, and will no longer fail the request automatically if any exception is thrown synchronously (like if an exception is thrown in an onSuccess or onFailure block). This removes a race, and makes Finagle more deterministic. RB_ID=832979



  • finagle: remove unused finagle-validate and finagle-testers packages. RB_ID=818726

Runtime Behavior Changes

  • finagle-core: DeadlineFilter is now per-connection, so the max rejection percentage is not shared across clients. This prevents a single client from exceeding the rejection budget. RB_ID=813731.
  • finagle-core: The use of keytool in PEMEncodedKeyManager has been removed and instead the keystore is being loaded from the pkcs12 file. RB_ID=832070
  • finagle-http: Local Dtabs are now encoded into the Dtab-Local header. X-Dtab headers may still be read but should be considered deprecated. RB_ID=815092
  • finagle-thrift: Removed duplicate “thrift” label on Thrift/ThriftMux scrooge-related server stats. RB_ID=816825

Breaking API Changes

  • finagle-redis: Deprecated ChannelBuffer exposing apis for string commands. RB_ID=817766.
  • finagle-core: DefaultClient has been removed. Implementors should prefer c.t.f.StackClient RB_ID=812681.
  • finagle-core: When a client is created, its server set resolution is started eagerly. RB_ID=806940
  • finagle-core: Dentry now takes a Dentry.Prefix instead of a Path. RB_ID=813914
  • finagle-core: Remove *.client.withTransport.socksProxy param as part of the initiative to move to CLI flags based configuration for SOCKS. RB_ID=842512
  • finagle-thrift/thriftmux: Thrift servers constructed using Thrift.serveIface now use Thrift.server.serveIface. ThriftMux servers constructed using ThriftMux.serveIface now use ThriftMux.server.serveIface. RB_ID=824865
  • finagle-cache-resolver: c.t.f.cacheresolver.ZookeeperCacheNodeGroup has been removed from the API since we no longer check for the zookeeper data for the cache pool size to refresh for the changes in the serverset. RB_ID=811190

New Features

  • finagle-http: http 1.1 running on netty4 is configurable via c.t.finagle.netty4.http.exp.Netty4Impl. It has not been tested in production and should be considered beta software. RB_ID=828188
  • finagle-core: Multi-line Dtabs may now contain line-oriented comments beginning with ‘#’. Comments are omitted from parsed Dtabs. RB_ID=818752
  • finagle-http: new stack params MaxChunkSize, MaxHeaderSize, and MaxInitialLineLength are available to configure the http codec. RB_ID=811129
  • finagle-mux: Mux now has support for fragmenting Tdispatch and Rdispatch payloads. This helps with head-of-line blocking in the presence of large payloads and allows long transmissions to be interrupted. RB_ID=794641.
  • finagle-core: Dtabs allow wildcard path elements in prefixes. RB_ID=813914
  • finagle-netty4: HTTP proxy support for any Finagle Netty 4 client. RB_ID=819752
  • finagle-core: Gauge for dns resolutions awaiting lookups. RB_ID=822410

Bug Fixes

  • finagle-http: Ensure that service closure is delayed until chunked response bodies have been processed. RB_ID=813110
  • finagle-stats: Ensure that histogram snapshotting does not fall behind if snapshot() is not called at least once per interval. RB_ID=826149


Runtime Behavior Changes

  • finagle-core: GenSerialClientDispatcher fails pending and subsequent requests when its underlying transport closes. RB_ID=807590

New Features

  • finagle-core: Include upstream/downstream addresses/client ids and request trace id in exceptions that extend c.t.f.HasRemoteInfo (including c.t.f.SourcedException), accessible via the remoteInfo value. RB_ID=797082
  • finagle-core: Introduce c.t.f.service.ResponseClassifier for HTTP servers, which allows developers to give Finagle the additional application specific knowledge necessary in order to properly classify responses.``RB_ID=800179``
  • finagle: Export two new histograms: request_payload_bytes and response_payload_bytes for the following protocols: HTTP (non-chunked), Mux, ThriftMux and Thrift. RB_ID=797821
  • finagle-core: Define c.t.f.Address to represent an endpoint’s physical location. Resolvers and namers may attach metadata such as weight to individual endpoint addresses. RB_ID=792209
  • finagle-http: Introduce convenience extractors to pattern match c.t.f.http.Response.status against the different categories. RB_ID=802953
  • finagle-http: Add toBoolean method in StringUtil to parse strings to boolean consistently. RB_ID=804056
  • finagle-http: Servers now actually decompress requests when decompression is turned on. RB_ID=810629
  • finagle-redis: Add support for SENTINEL commands. RB_ID=810663
  • finagle-redis: Support for Pub/Sub. RB_ID=810610

Breaking API Changes

  • finagle-core: c.t.f.Codec.prepareConnFactory(ServiceFactory) is marked final, override c.t.f.Codec.prepareConnFactory(ServiceFactory, Stack.Params) instead. RB_ID=797821

  • finagle-core: c.t.f.Codec.newClientDispatcher(Transport) is marked final, override c.t.f.Codec.newClientDispatcher(Transport, Stack.Params) instead. RB_ID=797821

  • finagle-core: Removed deprecations: RB_ID=800974 - Removed c.t.f.Service.release, replace usage with Service.close(). - Removed c.t.f.ServiceFactory.make, replace usage with ServiceFactory.apply. - Removed c.t.f.ProxyServiceFactory, replace usage with ServiceFactoryProxy. - Removed deprecated c.t.f.service.FailureAccrualFactory constructor. - Removed c.t.f.netty3.ChannelBufferBuf.apply, replace usage with ChannelBufferBuf.Owned.apply. - Removed c.t.f.util.InetAddressUtil.Loopback, replace usage with - Removed c.t.f.tracing.TracingFilter, replace usage with TraceInitializationFilter and (Client|Server)TracingFilter.

  • finagle-core: c.t.f.Addr.Bound.addr type changed from Set[SocketAddress] to Set[c.t.f.Address]. We provide a migration guide below for the most common cases.

    Callers of c.t.f.Addr.Bound.addr must handle Set[c.t.f.Address] instead of Set[SocketAddresses]. If you do something with the SocketAddress and expect the underlying type to be InetSocketAddress, use c.t.f.Address.Inet.addr to get the underlying InetSocketAddress.

    c.t.f.Addr constructors and c.t.f.Name.bound method now accept c.t.f.Address instead of SocketAddress. For most cases, wrapping the InetSocketAddress in an Address.Inet will fix the compile error.

    Any other SocketAddress subclass is currently incompatible with c.t.f.Address. Instead, you should encode any additional information in the metadata field of c.t.f.Address.Inet or c.t.f.exp.Address.ServiceFactory. RB_ID=792209

  • finagle-core: Delete c.t.f.ServiceFactorySocketAddress and replace usages with c.t.f.exp.Address.ServiceFactory. RB_ID=792209

  • finagle-core: Delete c.t.f.WeightedSocketAddress and instead use c.t.f.addr.WeightedAddress to represent address weights. RB_ID=792209

  • finagle-core: c.t.f.builder.ClientBuilder.hosts takes a Seq of InetSocketAddress instead of SocketAddress. If you get a compile error, change the static type to InetSocketAddress if you can. Otherwise, cast it at runtime to InetSocketAddress. RB_ID=792209

  • finagle-core: c.t.f.client.Transporter.EndpointAddr takes a c.t.f.Address as its parameter instead of SocketAddress. RB_ID=792209

  • finagle-core: c.t.f.service.FauilureAccrualFactory.Param(FailureAccrualPolicy) is removed - it’s not safe to configure Failure Accrual with a shareable instance of the policy, use () => FailureAccrualPolicy instead. RB_ID=802953

  • finagle-core: $Client.withSessionQualifier.failureAccrualPolicy has been removed from the API since it enables an experimental feature (use Stack’s .configured API instead). RB_ID=802953

  • finagle-core: c.t.f.service.exp.FailureAccrualPolicies (Java-friendly API) has been removed - use c.t.f.service.exp.FailureAccrualPolicy instead.

  • finagle-core: DefaultServer is removed. Protocol implementors should use StackServer instead. RB_ID=811918

  • finagle-memcached: c.t.f.memcached.protocol.text.Memcached no longer takes a StatsReceiver, pass it to a (Client/Server)Builder instead. RB_ID=797821

  • finagle-redis: c.t.f.redis.Redis no longer takes a StatsReceiver, pass it to a (Client/Server)Builder instead. RB_ID=797821

  • finagle-core: c.t.f.http.MapHeaderMap no longer takes a mutable.Map[String, Seq[String]] as a constructor parameter. apply method provides a similar functionality.

Bug Fixes

  • finagle-core: Fixed getAll method on c.t.f.http.MapHeaderMap, now it is case insensitive. apply method was altering the provided header names. This is fixed it is now possible to iterate on the original header names.


New Features

  • finagle-core: Introduce the c.t.f.service.PendingRequestFactory module in the client Stack. The module allows clients to limit the number of pending requests per connection. It is disabled by default. RB_ID=795491
  • finagle-core: Introduce the c.t.f.filter.ServerAdmissionControl module in the server Stack, which is enabled through the param c.t.f.param.EnableServerAdmissionControl. Users can define their own admission control filters, which reject requests when the server operates beyond its capacity. These rejections apply backpressure and allow clients to retry requests on servers that may not be over capacity. The filter implementation should define its own logic to determine over capacity. One or more admission control filters can be installed through the ServerAdmissionControl.register method. RB_ID=776385
  • finagle-core: Introduce c.t.f.service.ResponseClassifier which allows developers to give Finagle the additional application specific knowledge necessary in order to properly classify them. Without this, Finagle can only safely make judgements about transport level failures. This is now used by StatsFilter and FailureAccrualFactory so that application level failures can be used for both success metrics and failure accrual. RB_ID=772906
  • finagle-core: Added a new ‘Endpoints’ section on client pages, listing the weights, paths, and resolved endpoints for each dtab.``RB_ID=779001``
  • finagle-core: Introduce discoverable stack params which are available on every client/server via the with-prefixed methods. RB_ID=781833
  • finagle-memcached: Added c.t.f.memcached.BaseClient.checkAndSet which exposes the difference between a conflict and a not found result.
  • finagle-mux: Add a Wireshark dissector that can decode Mux messages. RB_ID=779482
  • finagle-stats: Define flag c.t.f.stats.statsFilterFile as GlobalFlag[Set[File]] to take comma-separated multiple files. RB_ID=793397
  • finagle-mux: Tinit/Rinit are now available and permit feature negotiation. RB_ID=793350


  • finagle-memcached: c.t.f.memcached.BaseClient.cas is deprecated in favor of the richer checkAndSet method.

Breaking API Changes

  • finagle-core: All the deprecated exceptions from Exceptions.scala have been removed. RB_ID=774658
  • finagle-thrift: Remove the framed attributes from c.t.f.Thrift.Client and c.t.f.Thrift.Server. This behavior may now be controlled with c.t.f.Thrift.param.Framed.
  • finagle-core: Unused c.t.f.builder.NonShrinkingCluster has been removed. RB_ID=779001
  • finagle-thrift: c.t.f.ThriftRichClient has a new abstract protected method responseClassifier: ResponseClassifier. If your implementation does not need this, you can implement it with ResponseClassifier.Default. RB_ID=791470

Runtime Behavior Changes

  • finagle-thrift,thriftmux: Deserialization of Thrift responses now happens as part of service application which means that it will now be part of the latency reported by StatsFilter. The actual latency as perceived by clients will not have changed, but for clients that spend significant time deserializing and do not have higher level metrics this may come as a surprise. RB_ID=772931
  • finagle-mux,thriftmux: The default closeTimeout in ping based failure detection is changed from Duration.Top to 4 seconds, to allow a session to be closed by default when a ping response times out after 4 seconds. This allows sessions to be reestablished when there may be a networking issue, so that it can choose an alternative networking path instead. RB_ID=773649

Breaking API Changes

  • finagle-thrift: Remove the framed attributes from c.t.f.Thrift.Client and c.t.f.Thrift.Server. This behavior may now be controlled with c.t.f.Thrift.param.Framed.




New Features

  • finagle-core: c.t.f.Server now has a serveAndAnnounce method that accepts a SocketAddress as an address. RB_ID=758862
  • finagle-core: c.t.f.service.Retries now supports adding delay between each automatic retry. This is configured via the Retries.Budget. RB_ID=768883
  • finagle-core: FailureAccrualFactory now uses a FailureAccrualPolicy to determine when to mark an endpoint dead. The default policy, FailureAccrualPolicy.consecutiveFailures(), mimicks existing functionality, and FailureAccrualPolicy.successRate() operates on the exponentially weighted average success rate over a window of requests.``RB_ID=756921``
  • finagle-core: Introduce c.t.f.transport.Transport.Options to configure transport-level options (i.e., socket options TCP_NODELAY and SO_REUSEADDR). RB_ID=773824
  • finagle-http: c.t.f.http.exp.Multipart now supports both in-memory and on-disk file uploads. RB_ID=RB_ID=769889
  • finagle-netty4: Hello World. Introduce a Listener for Netty 4.1. This is still considered beta. RB_ID=718688
  • finagle-netty4: Introduce ChannelTransport for Netty 4.1. RB_ID=763435
  • finagle-thrift: c.t.f.ThriftRichClient implementations of newServiceIface method that accept a label argument to pass to the ScopedStats instance. RB_ID=760157
  • finagle-stats: Added c.t.f.stats now has a statsFilterFile flag which will read a denylist of regex, newline-separated values. It will be used along with the statsFilter flag for stats filtering. RB_ID=764914


  • finagle-core: the #channelFactory method of c.t.f.builder.ServerBuilder has been deprecated in favor of the c.t.f.netty3.numWorkers flag. RB_ID=718688

Runtime Behavior Changes

  • finagle-core: The behavior for c.t.f.util.DefaultMonitor has changed such that unhandled exceptions are propagated to c.t.u.RootMonitor except for c.t.f.Failures with a log Level below INFO. RB_ID=758056
  • finagle-core: The metrics for requeues requeue/requeues, requeue/budget and requeue/budget_exhausted have moved under retries. They are now retries/requeues, retries/budget and retries/budget_exhausted. RB_ID=760213
  • finagle-core: c.t.f.service.RetryFilter and c.t.f.service.RetryExceptionsFilter now default to using a RetryBudget to mitigate retry amplification on downstream services. The previous behavior can be achieved by explicitly passing in RetryBudget.Infinite. RB_ID=766302
  • finagle-core: c.t.f.factory.TrafficDistributor now suppresses changes when a bound address is updated from a valid set to an error. Instead, it continues using stale data until it gets a successful update.
  • finagle-http: Unhandled exceptions from user defined HTTP services are now converted into very basic 500 responses so clients talking to those services see standard HTTP responses instead of a dropped connection. RB_ID=755846
  • finagle-memcached: Moved metrics from underlying KetamaPartitionedClient for Memcached clients to share the same scope of the underlying finagle client. RB_ID=771691
  • finagle-mux: com.twitter.finagle.mux.ThresholdFailureDetector is turned on by default. RB_ID=756213
  • finagle-serversets: The c.t.f.serverset2.Zk2Resolver now surfaces Addr.Pending when it detects that its underlying ZooKeeper client is unhealthy. Unhealthy is defined as non-connected for greater than its ‘unhealthyWindow’ (which defaults to 5 minutes). RB_ID=760771
  • finagle-serversets: The c.t.f.serverset2.ZkSession now uses an unbounded semaphore to limit to 100 outstanding zookeeper requests at any one moment. RB_ID=771399

Breaking API Changes

  • finagle-core: BackupRequestLost is no longer itself an Exception. Use BackupRequestLost.Exception in its place. RB_ID=758056
  • finagle-core: Replaced c.t.f.builder.ClientConfig.Retries with c.t.f.service.Retries.Policy. RB_ID=760213
  • finagle-core: A deprecated c.t.f.CancelledReadException has been removed. RB=763435
  • finagle-http: c.t.f.http.exp.Multipart.decodeNonChunked has been removed from the public API. Use c.t.f.http.Request.multipart instead. Also c.t.f.http.exp.Multipart.FileUpload is no longer a case class, but base trait for Multipart.InMemoryFileUpload and Multipart.OnDiskFileUpload. RB_ID=769889
  • finagle-mux: c.t.f.FailureDetector.apply method is changed to private scope, to reduce API surface area. Using FailureDetector.Config is enough to config session based failure detection behavior. RB_ID=756833
  • finagle-mux: closeThreshold in c.t.f.mux.FailureDetector.ThresholdConfig is changed to closeTimeout, from an integer that was used as a multiplier to time duration. This makes it easier to config. RB_ID=759406

Bug Fixes

  • finagle-thrift: c.t.f.ThriftRichClient scoped stats label is now threaded properly through newServiceIface RB_ID=760157


New Features

  • finagle-core: com.twitter.finagle.client.LatencyCompensator allows its default Compensator value to be set via an API call. This allows libraries to set defaults for clients that have not configured this module. RB_ID=750228
  • finagle-core: New Resolver com.twitter.finagle.FixedInetResolver extends InetResolver by caching successful DNS lookups indefinitely. It’s scheme is ‘fixedinet’. This is used by clients or resolvers that do not want or expect host->ip map changes (such as the zk2 resolver and twemcache client). RB_ID=753712

Runtime Behavior Changes

  • finagle-core: RetryPolicy.tries now uses jittered backoffs instead of having no delay. RB_ID=752629
  • finagle-core: FailureAccrualFactory uses jittered backoffs as the duration to mark dead for, if markDeadFor is not configured. RB_ID=746930
  • finagle-core: The transit latency (transit_latency_ms) and deadline budget (deadline_budget_ms) stats are now only recorded for servers, not for clients anymore, since they’re only meaningful for servers. RB_ID=75268
  • finagle-http: Clients sending requests with payloads larger than the server accepts (default 5MB) now receive a HTTP 413 response instead of a channel closed exception. RB_ID=753664

Breaking API Changes

  • finagle-core: TimerFromNettyTimer is renamed to HashedWheelTimer and the constructor accepting org.jboss.netty.util.Timer made private. For compatibility, HashedWheelTimer has additional constructors to match those provided by org.jboss.netty.util.HashedWheelTimer. RB_ID=748514
  • finagle-httpx / finagle-httpx-compat: Renamed to finagle-http and finagle-http-compat respectively. This changes the package names, e.g.: com.twitter.finagle.httpx to com.twitter.finagle.http. RB_ID=751876
  • finagle-core: Marked HandletimeFilter private[finagle], and renamed it to ServerStatsFilter. RB_ID=75268
  • finagle-zipkin: Drop c.t.zipkin.thrift.Annotation.duration and associated thrift field c.t.f.thrift.thrift.Annotation.duration. RB_ID=751986
  • finagle-stress: Project has been removed from Finagle. RB_ID=752201
  • finagle-swift: Project has been moved off of Finagle to . RB_ID=752826



  • finagle-http: Deprecated in favour of finagle-httpx and now removed.

New Features

  • finagle-core: Provides a RetryFilter which takes a RetryPolicy[(Req, Try[Rep])] and allows you to retry on both “successful” requests, such as HTTP 500s, as well as failed requests. The Req parameterization facilitates using the request to determine if retrying is safe (i.e. the request is idempotent).
  • finagle-httpx: Experimental support multipart/form-data (file uploads) decoding via c.t.f.httpx.exp.Multipart. RB_ID=730102

Runtime Behavior Changes

  • finagle-core: InetResolver.bind will now succeed if any hostname resolution succeeds. Previous behavior required that all hosts are successfully resolved. RB_ID=737748
  • finagle-core: DNS lookups in InetResolver are no longer cached within Finagle according to networkaddress.cache.ttl; we rely instead on however caching is configured in the JVM and OS. RB_ID=735006
  • finagle-core: After being revived, a FailureAccrualFactory enters a ‘probing’ state wherein it must successfully satisfy a request before accepting more. If the request fails, it waits for the next markDeadFor period. RB_ID=747541
  • finagle-serversets: DNS lookups in Zk2Resolver are no longer cached within Finagle according to networkaddress.cache.ttl; instead they are cached indefinitely. RB_ID=735006
  • finagle-redis: c.t.f.Redis now uses a pipelined dispatcher along with a concurrent load balancer to help eliminate head-of-line blocking.

Breaking API Changes

  • finagle-core: RetryingFilter, which takes a RetryPolicy[Try[Nothing]]` and is invoked only on exceptions, has been renamed to RetryExceptionsFilter. RetryExceptionsFilter is a subclass of RetryFilter, which takes a RetryPolicy[(Req, Try[Rep])] and allows you to retry on both “successful” requests, such as HTTP 500s, as well as failed requests. The Req parameterization facilitates using the request to determine if retrying is safe (i.e. the request is idempotent).
  • finagle-core: Name.all is now private to com.twitter.finagle.
  • finagle-memcached: Unified stack-based construction APIs and cleanup internal constructors. In particular, KetamaClient was removed and KetamaPartitionClient and KetamaFailureAccrualFactory are now sealed inside Finagle. See [[com.twitter.finagle.Memcached]] for how to construct a finagle-memcached client.
  • finagle-redis: Port the c.t.f.Redis protocol object to the StackClient API. A redis client can now be constructed and configured like the rest of the finagle subprojects.


New Features

Runtime Behavior Changes

  • finagle-core: Weights are no longer supported by the load balancers. They are moved one level above and interpreted by a new module, the TrafficDistributor. This frees the balancers to have non-linear load metrics. It also changes the semantics of weights. They are now normalized by size of endpoints that share the same weight and interpreted proportional to offered load (however, they can still be though of, roughly, as multipliers for traffic). RB_ID=677416
  • finagle-core: The RequestSemaphoreFilter now sheds load by dropping the tail of the queue and failing it with a Failure.Restartable. Previously, the filter had an unbounded queue but now the default size is 0 (i.e. no queueing). The dropped requests are in turn requeued by Finagle clients with protocol support (e.g. Http, ThriftMux). RB_ID=696934
  • finagle-core: ServerBuilder.ServerConfig.BindTo, ServerBuilder.ServerConfig.MonitorFactory, and ServerBuilder.ServerConfig.Daemonize, are now private to com.twitter.finagle.builder. RB_ID=730865
  • finagle-memcachedx: Renamed to finagle-memcached.
  • finagle-stats: Standard deviation (“$statName.stddev”) is no longer exported. RB_ID=726309 (follow up to RB_ID=717647)
  • finagle-serversets: namer/bind_latency_us stat now counts only time in name resolution, not service acquisition. namer/{dtabcache,namecache,nametreecache}/misstime_ms stats are no longer exported. RB_ID=730309

Breaking API Changes

  • finagle-core: c.t.f.jsr166y has been replaced with Java 7 API. finagle: Replace JSR166y with Java 7 API. RB_ID=720903
  • finagle-core: LoadBalancerFactory no longer takes endpoints with weights as per the decoupling mentioned in runtime changes. RB_ID=677416
  • finagle-core: RequestSemaphoreFilter.Param now accepts a com.twitter.concurrent.AsyncSemaphore instead of an integer representing the max concurrency. RB_ID=696934
  • finagle-core: removed c.t.f.asyncDns flag and c.t.f.SyncInetResolver; DNS resolution is now always asynchronous. RB_ID=734427
  • finagle-core: ClientBuilder.ClientConfig.DefaultParams, ClientBuilder.ClientConfig.DestName, ClientBuilder.ClientConfig.GlobalTimeout, ClientBuilder.ClientConfig.Daemonize, and ClientBuilder.ClientConfig.MonitorFactory are now private to com.twitter.finagle.builder. ClientBuilder.ClientConfig.Retries is now private to com.twitter. RB_ID=727245
  • finagle-httpx: Method no longer has an extractor. To access the name of custom methods, use toString. RB_ID=722913
  • finagle-mux: c.t.f.mux.exp.FailureDetector and c.t.f.mux.exp.sessionFailureDetector are moved out of exp package into mux package. RB_ID=725350


New Features

  • finagle-http: Support nacks between Finagle Http clients and servers. When a server fails with retryable exceptions (exceptions wrapped by Failure.rejected), it sends back a “Nack” response, i.e. 503 Response code with a new “finagle-http-nack” header. This allows clients to safely retry failed requests, and keep connections open. RB_ID=705948

Runtime Behavior Changes

  • finagle-core: FailFast parameter renamed from onOrOff to enabled. RB_ID=720781
  • finagle-core: When evaluating NameTree unions, return components of the union in Ok state rather than waiting for all components to be Ok. This enables resilience of unions when part of the tree cannot be resolved. RB_ID=697114
  • finagle-stats: Standard of deviation is no longer calculated. It is exported as a constant 0.0 for “$statName.stddev”. RB_ID=717647

Breaking API Changes

  • finagle-stream: Introduce StreamRequest as a replacement for Netty’s HttpRequest, and converted the rest of the public API to not leak other Netty types (notably ChannelBuffer is replaced by Buf). RB_ID=695896
  • finagle-core: Dtab does not implement the Namer interface anymore. Use c.t.f.naming.DefaultInterpreter to bind a name via a Dtab. Support for Dtab entries starting with /#/ has been removed. c.t.f.Namer.bindAndEval has been removed. Use c.t.f.Namer.resolve instead. RB_ID=711681
  • finagle: LoadService and ThriftRichClient migrated off of deprecated ClassManifest to ClassTag. RB_ID=720455



  • finagle-memcached: Deprecated in favor of finagle-memcachedx and now removed.

New Features

  • finagle-httpx: Support nacks between Finagle Http clients and servers. When a server fails with retryable exceptions (exceptions wrapped by Failure.rejected), it sends back a “Nack” response, i.e. 503 Response code with a new “finagle-http-nack” header. This allows clients to safely retry failed requests, and keep connections open. RB_ID=670046

Breaking API Changes

  • finagle-core: Moved netty3 specific things into a netty3 namespace. For these symbols, the namespace translation follows this pattern: c.t.f.$MODULE._ => c.t.f.netty3.$MODULE._. RB_ID=691746
  • finagle-core: Define WeightedSocketAddress as a case class. Add WeightedSocketAddress.extract method to extract weight. RB_ID=614228
  • finagle-core: Constructing a new Balancer that can be injected into a Finagle client was unnecessarily complex and non-uniform. We removed the legacy constructors around defining the collection of endpoints and simplified the interface to LoadBalancerFactory. Now, com.twitter.finagle.loadbalancer.Balancers defines the collection of balancer constructors. RB_ID=660730
  • finagle-core: Aperture can no longer be enabled via command line flags. Configuring per-client settings globally is generally not a good idea and we’re working to remove these flags from Finagle. Use the constructors in com.twitter.finagle.loadbalancer.Balancers to create an instance that can be injected into a client. RB_ID=663194
  • finagle-core: The default load balancer has changed to p2c from heap. RB_ID=693450
  • finagle-core: Service.isAvailable and ServiceFactory.isAvailable is finalized. Service.status and ServiceFactory.status supersedes isAvailable usage since 6.24.0 release. RB_ID=678588
  • finagle-core: ClientBuilder.failureAccrual method is removed. Use ClientBuilder.failureAccrualFactory instead. RB_ID=689076
  • finagle-core: Stack param ClientBuilder.ClientConfig.FailureAccrualFac is removed. Use ClientBuilder.failureAccrualFactory instead. RB_ID=689076
  • finagle-exception: com.twitter.finagle.exception.ExceptionReporter is no longer used as the default com.twitter.finagle.util.ReporterFactory. RB_ID=674646
  • finagle-kestrel: Replace deprecated finagle-kestrel package with finagle-kestrelx. RB_ID=667920
  • finagle-core: Add new method noFailureAccrual on ClientBuilder that completely disables FailureAccrualFactory in the underlying stack. RB_ID=689076

New Features

  • finagle-thrift: Support for finagle Services per thrift method.


Breaking API Changes

  • finagle-core: c.t.f.builder.Server now implements c.t.f.ListeningServer.
  • finagle-core: c.t.f.Server.serveAndAnnounce with a ServiceFactory had its first argument renamed to name from forum.
  • finagle-core: Add an attribute map to c.t.f.Addr.Bound.
  • finagle-core: c.t.f.builder.ClientConfig.FailFast has moved to c.t.f.FailFastFactory.FailFast.
  • finagle-core: NoBrokersAvailableException now has two Dtab constructor arguments, both the base and local Dtabs.
  • finagle-core: c.t.f.Failure convenience constructors (e.g., Failure.Cause, Failure.Rejected) were removed in favor of uniform flag treatment, and clean separation of attributes from interpretation of those attributes.
  • finagle-core: ExitGuard usage is now private to finagle.
  • finagle-core: c.t.f.service.TimeoutFilter.module is now split into TimeoutFilter.clientModule and TimeoutFilter.serverModule.
  • finagle-core: remove deprecated c.t.f.builder.ClientBuilder.stack taking a Stack.Params => Client[Req1, Rep1].
  • finagle-core: StackRegistry.Entry takes different constructor arguments, and the name has been bundled in with the Stack.Params. StackRegistry.Entry is only used internally, so this should be relatively inexpensive. Similarly, StackRegister#register has also had a small change to its method signature along the same lines.
  • finagle-http: deprecated methods in c.t.f.http.HttpMessageProxy have been removed.
  • finagle-memcached / finagle-memcachedx: move TwitterCacheResolver and related objects to new finagle-cacheresolver package.
  • finagle-memcached / finagle-memcachedx: failureAccrual param in ReplicationClient is changed from type (Int, Duration) to (Int, () => Duration), to allow flexibility to config duration. Also see markDeadFor change in finagle-core in the “New Features” section below.
  • finagle-memcached / finagle-memcachedx: MigrationClientTest now uses ServerCnxnFactory from com.twitter.zk rather than NIOServerCnxn.Factory from org.apache.zookeeper.server.
  • finagle-mux: c.t.f.mux.RequestNackedException is removed in favor of a standard Failure (c.t.f.Failure.Rejected).
  • finagle-ostrich4: Switched dependency to finagle-httpx from finagle-http.
  • finagle-serversets: ZkInstance in tests now uses ServerCnxnFactory from com.twitter.zk rather than NIOServerCnxn.Factory from org.apache.zookeeper.server.
  • finagle-stats: Switched dependency to finagle-httpx from finagle-http.
  • finagle-mysql: PreparedStatements are now more type-safe! The type signature of PreparedStatements has changed from Seq[Any] => Future[Result] to Seq[Parameter] => Future[Result]. Parameter represents objects that are serializable by finagle-mysql. In most cases, scalac should transparently wrap your arguments in Parameter when applying a PreparedStatement. However, in cases where this doesn’t happen you can explicitly wrap them using Parameter.wrap.

Runtime Behavior Changes

  • finagle-core: com.twitter.finagle.service.StatsFilter no longer requires a com.twitter.finagle.stats.RollupStatsReceiver for correct behaviour, and providing one will double count failures.
  • finagle-core: com.twitter.finagle.factory.TimeoutFactory will fail with a retryable com.twitter.finagle.Failure when it times out.
  • finagle-core: com.twitter.finagle.pool.WatermarkPool will fail with an interrupted com.twitter.finagle.Failure when it is interrupted while waiting or trying to establish a connection. It has previously failed with a com.twitter.finagle.WriteException when trying to establish a connection, but it’s incorrect to retry on an interruption.
  • finagle-core: com.twitter.fiangle.RetryPolicy’s RetryableWriteException and WriteExceptionsOnly will not retry on com.twitter.finagle.Failure`s that are marked `InterruptedBy, even if they are Retryable.
  • finagle-core: The error message provided by c.t.f.NoBrokersAvailableException prints both the base and local Dtabs.
  • finagle-core: Stats produced by com.twitter.finagle.factory.BindingFactory are now scoped with the “namer” prefix rather than “interpreter”. The total latency associated with Name binding is now recorded in the “bind_latency_ms” stat.
  • finagle-core: The “service_creation/service_acquisition_latency_ms” stat produced by com.twitter.finagle.factory.StatsFactoryWrapper no longer includes time spent in name resolution, which is now covered by “namer/bind_latency_us” as discussed above.
  • finagle-core: added transit_latency_ms and deadline_budget_ms stats.
  • finagle-core: Automatic retries (requeues) are now credited as a ratio of requests over a window of time, instead of a fixed limit. The stats scope has also changed from “automatic” to “requeues”.


  • finagle-core: c.t.f.builder.Server.localAddress is deprecated in favor of c.t.f.ListeningServer.boundAddress.

New Features

  • finagle-core: Fail fast is now configurable on Stack-based clients via the com.twitter.finagle.FailFastFactory.FailFast param.

  • finagle-core: com.twitter.finagle.service.StatsFilter is now configurable with an com.twitter.finagle.stats.ExceptionStatsHandler to customize how failures are recorded.

  • finagle-core: It should be safe to match on com.twitter.finagle.Failure.InterruptedBy to tell if a com.twitter.util.Future failed due to being interrupted.

  • finagle-core: markDeadFor in c.t.f.service.FailureAccrualFactory.Param is changed from Duration type to () => Duration. So it’s flexible for clients to pass in a function that specifies Duration. For example, c.t.f.service.FailureAccrualFactory provides a function that adds perturbation in durations. Stack-based API and c.t.f.builder.ClientBuilder support both types for client configuration. For example,

    Thrift.client.configured(FailureAccrualFactory(5, () => 1.seconds))
    // or
    Thrift.client.configured(new FailureAccrualFactory(5, 1.seconds)).

    c.t.f.client.DefaultClient does not support Duration type in failureAccrual anymore.

  • finagle-core: improved Java compatiblity for c.t.f.Stack.Params / c.t.f.Stack.Parameterized.

  • finagle-core: Introduce the ability to add metadata to a bound com.twitter.finagle.Addr.

  • finagle-core: Introduce per-address latency compensation. Clients may be configured with a ‘Compensator’ function that uses the client’s address metadata to adjust connection and request timeouts. This can be used, for instance, to account for speed-of-light latency between physical regions.

  • finagle-core: Introduce per-address stats scoping. Clients may be configured with a com.twitter.finagle.client.StatsScoping.Scoper function that uses the client’s address metadata to adjust the scope of client stats. This can be used, for instance, to properly scope client stats for a Name that resolves to a Union of distinct clusters.

  • finagle-core: A convenient method Client.newService(dest: String, label: String) was added.

  • finagle-core: ExitGuard now has an ‘explainGuards’ method to provide a human-readable description of exit guards that are still active.

  • finagle-http(x): Two missing params were added: Decompression and CompressionLevel. Both client and server may be configured with either configured method or withDecompression/ withCompressionLevel.

  • finagle-mysql: Add support for MySQL transactions.

  • finagle-stats: A new HostStatsReceiver type is added and used for per host stats. It is loaded through LoadService and used by the Stack-based API as a default param. Per host stats can be turned on through com.twitter.finagle.loadbalancer.perHostStats flag, and is exported to the “/admin/per_host_metrics.json” route in twitter-server.

  • finagle-stats: Improved compatibility when migrating from Ostrich stats via two flags: com.twitter.finagle.stats.useCounterDeltas=true and com.twitter.finagle.stats.format=ostrich. If these flags are both set, HTTP requests to /admin/stats.json with the period=60 query string parameter will replicate Ostrich’s behavior by computing deltas on counters every minute and formatting histograms with the same labels Ostrich uses.

  • finagle-memcached(x): Add c.t.f.memcached.Memcached which provides a Stack based Memcache client that uses pipelining.

Bug Fixes

  • finagle-core: c.t.f.Server.serveAndAnnounce for a Service had its usage of name and addr transposed.

Miscellaneous Cleanup


Breaking API Changes

  • finagle-core: Remove c.t.f.client.StackClient.Role.loadBalancer, which was unused and duplicated by c.t.f.loadbalancer.LoadBalancerFactory.role.

  • finagle-core: c.t.f.Namer.orElse was removed; composing Namers may be accomplished by constructing an appropriate Dtab.

  • finagle-core: removed experimental enum / expand from c.t.f.Namer and alt / union from c.t.f.Dtab.

  • finagle-http: Remove c.t.f.http.CheckRequestFilter along with c.t.f.http.CheckHttpRequestFilter. The functionality has been added to c.t.f.http.codec.HttpServerDispatcher. In addition, the codecError in c.t.f.http.BadHttpRequest has been replaced with the exception thrown by the HttpServerCodec.

  • finagle-httpx: Remove deprecated code, limited scope of access on internal classes.

  • finagle-mux: no longer calls Thread.start() in its constructor. This should be now be done by the caller.

  • finagle-mux: The experimental session API is discontinued.

  • finagle-mux: Introduce new Request and Response types for mux services. The new mux request includes a destination path so that, which corresponds to the destination field in Tdispatch requests. Furthermore, these new types expose instead of Netty’s ChannelBuffers.

  • finagle-thrift,finagle-thriftmux: c.t.f.Thrift.Client, c.t.f.Thrift.Server, c.t.f.ThriftMux.Client and c.t.f.ThriftMux.Server have their TProtocolFactory configured via a c.t.f.thrift.param.ProtocolFactory Stack.Param.

  • finagle-thriftmux: c.t.f.ThriftMux.Client now has its ClientId configured via a c.t.f.thrift.param.ClientId Stack.Param.

  • Traces (com.twitter.finagle.tracing.Trace) lose their local-state mutating methods: Trace.clear, Trace.pushId, Trace.setId, Trace.setTerminalId, Trace.pushTracer, Trace.pushTracerAndSetNextId, Trace.state_=, and Trace.unwind. Let-bound versions of these are introduced in their stead. This makes it simple to ensure that state changes are properly delimited; further, these are always guaranteed to be delimited properly by Finagle.

    // Let-bound version:
    Tracer.letTracer(tracer) {
  • Context handlers (com.twitter.finagle.Context) are removed. They are replaced by the use of marshalled request contexts (com.twitter.finagle.context.Contexts.broadcast). Marshalled request contexts do not require the use of service loading, so their use no longer requires build system coordination. We show Finagle’s trace context: the first version uses the old context handler mechanism; the second uses Contexts.broadcast.

    // The old context handler for Finagle's tracing context. Note that this
    // also required the file
    // finagle-core/src/main/resources/META-INF/services/com.twitter.finagle.ContextHandler
    // to contain the fully qualifed class path of the below object.
    class TraceContext extends ContextHandler {
      val key = Buf.Utf8("com.twitter.finagle.tracing.TraceContext")
      def handle(body: Buf) {
        // Parse 'body' and mutate the trace state accordingly.
      def emit(): Option[Buf] = {
        // Read the trace state and marshal to a Buf.
    // New definition. No service loading required.
    private[finagle] val idCtx = new Contexts.broadcast.Key[TraceId] {
      val marshalId = Buf.Utf8("com.twitter.finagle.tracing.TraceContext")
      def marshal(id: TraceId): Buf = {
        // Marshal the given trace Id
      def tryUnmarshal(body: Buf): Try[TraceId] = {
        // Try to marshal 'body' into a trace id.

Runtime Behavior Changes

  • finagle-mux: Mark the ServiceFactory available again if the underlying Service is no longer available. This permits it to be closed and reused.
  • finagle-mux: Rename the “lease_counter” counter to “leased” on mux clients.


  • finagle-core: Deprecated the mechanisms of FailureAccrual that use factory Transformers. It’s better to just use the Params to configure the existing FailureAccrualFactory. However, if you’ve actually written your own failure accrual transformer that’s significantly different, then you can do stack.replace() to swap it in.
  • finagle-memcached: Have cas() operation return false on NotFound() state instead of throw IllegalStateException

New Features

  • finagle-core: All Stack.Param`s used in `ClientBuilder and ServerBuilder are now publicly exposed for configuration parity.
  • finagle-mux: Drain mux servers properly, so that shutdowns can be graceful.
  • finagle-core: Introduce Service.status which supersedes Service.isAvailable. Service.status is a fine-grained health indicator. The default definition of Service.isAvailable is now defined in terms of Service.status; this definition will soon be made final.
  • finagle-mux: Inject bound residual paths into mux requests.
  • Request contexts. Request contexts replace the direct use of com.twitter.util.Local and of com.twitter.finagle.Context. Request contexts are environments of request-local bindings; they are guaranteed to be delimited by Finagle, and their API admits only properly delimited binding. They come in two flavors: Contexts.local are always local to handling a single request; bindings in Contexts.broadcast may be marshalled and transmitted across process boundaries where there is protocol support. Currently, both Thrift and Mux (and thus also ThriftMux) support marshalled contexts. See com.twitter.finagle.contexts.Context for more details.


Breaking API Changes

  • finagle-core: c.t.f.Stackable`s maintained state about which parameters were accessed via `get. This was error prone and violated the assumption that Stack`s are immutable data structures. We removed this in favor of annotating modules with parameters. The abstract classes for Stackables were also simplified. Now we only have `Module and ModuleN variants which are more convenient for most definitions. Since this is an advanced API, it should not impact standard usage of finagle.
  • finagle-core: Update ConcurrentRingBuffer to use ClassTag instead of ClassManifest; rename size argument to capacity.


  • ServerBuilder.stack[Req1, Rep1](mk: Stack.Params => Server[Req1, Rep1]) is deprecated in favor of ServerBuilder.stack[Req1, Rep1](server: Stack.Parameterized[Server[Req1, Rep1]])

Runtime Behavior Changes

  • finagle: Improve allocation semantics for uses of Buf.


Breaking API Changes

  • finagle-core: Removed unused com.twitter.finagle.service.ProxyService. It wasn’t sufficiently general to be used outside of finagle, and was no longer used in finagle.
  • Removed TLSEngine, and replaced it with two, TLSClientEngine, and TLSServerEngine, where TLSServerEngine is the same as TLSEngine, and TLSClientEngine takes a SocketAddress instead of (). Additionally, the Netty3TransporterTLSConfig now takes a function SocketAddress => Engine, instead of () => Engine.

New Features

  • finagle-core: BroadcastStatsReceiver, introduce specialized implementation
  • finagle-core: Introduce gauges in SummarizingStatsReceiver
  • finagle-core: Introduce Transport#copyToWriter
  • finagle-core: Make base Dtab used in BindingFactory a Stack.Param
  • finagle-core: Proper decay in experimental ewma load metric
  • finagle-core: Simplify Stack{Client, Server} and unify around them

Runtime Behavior Changes

  • finagle-core: Add support for non-URLClassloaders to LoadService
  • finagle-core: clear locals before entering server dispatch loop
  • finagle-core: Defer DNS Resolution in InetResolver to FuturePool
  • finagle-core: for paths starting with /#/, skip rewrites where prefix is /
  • finagle-core: include name resolution in tracing request span
  • finagle-core: Properly wrap some IOException into ConnectionFailedException
  • finagle-core: Scope InetResolver’s stats properly
  • finagle-http: Send “Connection: close” header while dispatcher is closing
  • finagle-http: Set content length header when appropriate
  • finagle-memcached: Use interruptible future for the client request readiness
  • finagle-stats: Add content-type response header to JsonExporter
  • finagle-thrift: Add back connection_preparation_latency stat in Thrift
  • finagle-thriftmux: Record protocol as a gauge rather than a counter


  • finagle-core: Add Scaladocs for ChannelBufferBuf and BufChannelBuffer
  • finagle-core: link to the FAQ in FailedFastException
  • finagle-serversets: Defer DNS resolution for endpoints to InetResolver
  • finagle-thrift{,mux}: Clarified with* deprecation warning
  • Fix minor issues and missing code blocks in Finagle documentation


  • finagle-core: GlobalFlag isn’t caching the property value
  • finagle-core: recursive-descent Path / NameTree / Dentry / Dtab parsers to reduce heap allocation

Bug Fixes

  • finagle-core: Fix a deadlock in Contexts
  • finagle-core: Fix breaking ABI change in SummarizingStatsReceiver
  • finagle-core: Fix bug in computing array index in SummarizingStatsReceiver
  • finagle-core: Fix location for maven builds
  • finagle-core: Fix synchronization in LeasedFactory
  • finagle-core: Fix tracing with Stack{Client, Server}
  • finagle-core: Make FailedFastException an instance variable.
  • finagle-core: Synchronized access to the Stackable mutable.params map
  • finagle-http: Fix CookieMap.rewriteCookieHeaders()
  • finagle-http: Fix the memory leak in HttpClientDispatcher
  • finagle-mysql: Fix timestamp fractional seconds encoding
  • finagle-mysql: Properly heed timezone when extracting TimestampValue
  • mux: clear contexts after receive, not in ‘finally’ clause


  • finagle: Upgrade to scala_2.10
  • finagle-core: Add weighted address support to InetResolver.
  • finagle-core: Adds ClientRegistry.expAllRegisteredClientsResolved
  • finagle-core: Attach Dtab.local to NoBrokersAvailableException in filter
  • finagle-core: Attempt to add dtab stats to all clients and servers
  • finagle-core: Avoid SOCKS proxy for both loopback and link-local addresses
  • finagle-core: Bind names lazily under Alt so we don’t do needless lookups
  • finagle-core: DelayedFactory to detachable implementation
  • finagle-core: Fix a race in load balancer initialization
  • finagle-core: Improve loadbalancer logging
  • finagle-core: Introduce ewma load metric
  • finagle-core: Log state for ewma load metric
  • finagle-core: Redesign of twitter-server admin page
  • finagle-core: Register StackClient with Path dest in ClientRegistry as evaluated against Dtab.base Problem
  • finagle-core: Rewrote ServiceLoader to avoid creating
  • finagle-core: SingletonPool: a single-service pool with good semantics
  • finagle-core: Zipkin tracing for name resolution
  • finagle-core: fix synchronization in SummarizingStatsReceiver
  • finagle-core: reusing pool: isAvailable === underlying.isAvailable
  • finagle-docs: A better picture for filters. (Replaces hand-drawn monstrosity.)
  • finagle-docs: Add Scaladocs for all public exception classes in Finagle.
  • finagle-docs: Add a section to the FAQ regarding FailedFastExceptions
  • finagle-exp: Generify the DarkTrafficFilter problem
  • finagle-guide: Document stabilizing serverset metrics.
  • finagle-http: Add support for a Dtab-Local header
  • finagle-http: Fail requests with invalid X-Dtab headers
  • finagle-http: Fail requests with invalid X-Dtab headers
  • finagle-http: TextualContentCompressor should compress textual Content-Type’s even when containing a charset
  • finagle-mux,thriftmux: explain why the files are named Netty3
  • finagle-mux: Better gc avoidance flags for experimentation
  • finagle-mux: Enable gc avoidance for parallel gc
  • finagle-mux: Improve mux’s handling of client disconnects
  • finagle-mux: Improved Garbage Collection Avoidance Docs
  • finagle-mux: docs and minor cleansing in Message subclasses
  • finagle-mysql: Switches PreparedCache over to util-cache FutureCache
  • finagle-serversets: Add support for getEphemerals ZooKeeper call
  • finagle-serversets: Memoize getChildrenWatchOp instead of globPrefixWatchOp
  • finagle-serversets: Reuse ObjectMapper in JSON parser.
  • finagle-serversets: add latency metrics for ServerSet2.
  • finagle-zipkin: Reduce allocations when tracing


  • finagle: Smattering of minor cleanups in util and finagle
  • finagle: Upgrade sbt to 0.13
  • finagle: Upgrade to Netty
  • finagle-core: Add NameTree.Fail to permit failing a name without fallback
  • finagle-core: Add a generic DtabStatsFilter
  • finagle-core: Add a singleton exception and a counter in WatermarkPool
  • finagle-core: DefaultClient in terms of StackClient
  • finagle-core: Disable Netty’s thread renaming
  • finagle-core: Fix CumulativeGauge memory leak
  • finagle-core: Fix negative resolution in
  • finagle-core: Fixed ChannelStatsHandler to properly filter exceptions
  • finagle-core: Forces finagle-core to use ipv4 network stack
  • finagle-core: Improve Failure.toString
  • finagle-core: Include path and Dtab.local in NoBrokersAvailableException
  • finagle-core: Log exceptions caught by ChannelStatsHandler
  • finagle-core: Make timer-based DNS resolution as default of InetResolver
  • finagle-core: Reader and getContent symmetry
  • finagle-core: Reduces log level for common exceptions
  • finagle-core: Register clients centrally
  • finagle-doc: Add fintop to companion projects list on Finagle website
  • finagle-http: Don’t emit (illegal) newlines in lengthy dtab header values
  • finagle-http: Fix code style from an open-source contribution
  • finagle-http: Migrate from specs to scalatest
  • finagle-kestrel: Make transaction abort timeout configurable in MultiReader
  • finagle-mux: Added extra client logging
  • finagle-mux: Fix broken draining behavior
  • finagle-mux: Improve granularity of rate to bytes/millisecond
  • finagle-serversets: Handle errors that occur when fetching endpoints
  • finagle-serversets: Increase ZK session timeout to 10 seconds
  • finagle-serversets: Merge WeightedSocketAddresses with same host:port but different weight in Stabilizer
  • finagle-serversets: Synchronize bug fixes & test coverage across ZK facades
  • finagle-swift: Fixes pants build warning
  • finagle-thrift: Add explicit dependency on libthrift
  • finagle-thrift: Remove usage of java_sources, should be able to depend on it normally


  • finagle-core: Allow trailing semicolons in dtabs
  • finagle-core: Rescue exceptions thrown by filter in Filter.andthen(Filter)
  • finagle-core: StackClient, StackClientLike don’t leak underlying In, Out types
  • finagle-doc: Clarify cancellation
  • finagle-doc: Fix broken link in document
  • finagle-doc: Fix name footnote in finagle Names docs
  • finagle-http: Buf, Reader remove Buf.Eof; end-of-stream is None
  • finagle-http: Prepend comment to JSONP callbacks
  • finagle-http: Removing specs from the CookieMapSpec test.
  • finagle-kestrel: Make failFast configurable in Kestrel codec
  • finagle-mysql: Ensure mysql specific tracing is composed.
  • finagle-mysql: Finagle MySQL PreparedStatement accepts Value types as params.
  • finagle-serversets: Identity Providers for Serverset2
  • finagle-thriftmux: Add withProtocolFactory API endpoint
  • finagle-thriftmux: Don’t reuse InMemoryStatsReceiver in the same test


  • finagle-*: release scrooge v3.16.0
  • finagle-*: release util v6.18.0
  • finagle-core: Add description field to com.twitter.finagle.Stackable trait
  • finagle-core: Add a Flag to turn on per-host stats
  • finagle-core: Add a service acquisition latency stat to StatsFactoryWrapper
  • finagle-core: Don’t support empty path elements in com.twitter.finagle.Path
  • finagle-core: Improves FailFastFactory documentation
  • finagle-core: Make c.t.f.Failure a direct subclass of Exception
  • finagle-core: Skip SOCKS proxy when connecting to loopback address
  • finagle-core: Use Monitor from caller’s context in DefaultTimer
  • finagle-http: Add “Enhance Your Calm” and “Too Many Requests” HTTP status codes
  • finagle-http: Add exp.HttpServer, which allows request limits to be configured
  • finagle-http: Change Request#params to a memoized def
  • finagle-http: Stream request body
  • finagle-kestrel: Add Name-based methods for MultiReader construction
  • finagle-memcached: Expose the client type KetamaClient in the build() API
  • finagle-mux: GC Avoidance Algorithm
  • finagle-mux: Hook up GC avoidance to servers
  • finagle-mux: Move to the correct directory
  • finagle-serversets: Randomizes backoff interval in ZK2
  • finagle-serversets: Start resolution eagerly in ZK2
  • finagle-stats: Add a stat-filtration GlobalFlag
  • ostrich: release ostrich v9.5.2
  • user guide: Add Google Analytics tracking code
  • user guide: Add sections about review process and starter issues
  • user guide: Update Finagle adopter list on user guide website
  • wily: Add Dtab expansion


  • finagle: Add list of Finagle adopters
  • finagle: Upgrade third-party dependencies
  • finagle-core: Add Addr.Neg to the user guide’s list of Addr types
  • finagle-core: Added Failure support for sourcing to finagle
  • finagle-core: ClientBuilder should turn per-host stats off by default (matching new Client building API).
  • finagle-core: Implement DefaultServer in terms of StackServer
  • finagle-core: Improve the Dtab API
  • finagle-core: Prevent scoping stats with the empty-string
  • finagle-core: Rolls up the /tries scope properly
  • finagle-core: ServerStatsReceiver and ClientStatsReceiver can now update their root scope
  • finagle-core: fix race case in DelayedFactory
  • finagle-core: introduce AbstractResolver
  • finagle-core: remove need for hostConnectionLimit when using ClientBuilder#stack
  • finagle-core: widen to type for ServerBuilder#stack
  • finagle-core: widen type of ClientBuilder#stack
  • finagle-doc: Removed a line from
  • finagle-http: DtabFilter should always clear dtab headers
  • finagle-http: add HOST header for CONNECT method
  • finagle-http: scala 2.10 compatible tests
  • finagle-memcached: filter out one more cancelling request exception in failure accrual
  • finagle-memcached: remove empty test
  • finagle-mux: Improve Mux server close behavior, control messages to non-Mux clients
  • finagle-mux: Marked a gc test as flaky
  • finagle-mux: Modifies MuxService to essentially be a Service[Spool[Buf], Spool[Buf]] Problem
  • finagle-mux: Rm ClientHangupException in favor of CancelledRequestException
  • finagle-mysql: Retrieving a timestamp from the DB nw creates a timestamp in UTC
  • finagle-mysql: fix for issue where time was not being returned in UTC for binary protocol
  • finagle-serversets: Prevent gauges from being garbage collected
  • finagle-thrift: Blackhole control messages sent to non-mux Thrift clients
  • finagle-thriftmux: Add per-connection protocol-usage stats
  • finagle-thriftmux: Add stats to identify ThriftMux clients and servers
  • finagle-thriftmux: Propagate Contexts from non-ThriftMux clients
  • finagle-thriftmux: add ClientBuilder#stack compatibility and make APIs symmetric
  • finagle-thriftmux: pass along ClientId with ClientBuilder API


  • finagle-core: Add Stack#remove
  • finagle-core: Add a copy constructor to Stack{Client, Server}
  • finagle-core: Fixed a typo in scaladoc
  • finagle-core: Implement ClientBuilder in terms of StackClient
  • finagle-core: Invert the cancelOnHangup value passed to MaskCancelFilter.Param
  • finagle-core: Liberate Failure
  • finagle-core: Log all services loaded by c.t.finagle.util.LoadService
  • finagle-core: Minor cleanup
  • finagle-core: Properly close sockets on shutdown
  • finagle-core: Properly scope stats by label in Stack{Client,Server}
  • finagle-core: Remove Stack{Server,Client}.transformed
  • finagle-core: Scoped the RollupStatsReceiver carefully
  • finagle-core: Thread through Codec#newClientTransport in ClientBuilder
  • finagle-core: Update to netty-3.9.1.Final
  • finagle-example: Add Java Thrift client and server
  • finagle-http: Add Csv,Xls,Zip to finagle MediaType
  • finagle-http: Adds tls support to finagle 6 apis
  • finagle-http: Set the response content-length header to 0 in ExceptionFilter.
  • finagle-kestrel: Add Thrift support to Kestrel MultiReader in Finagle-Kestrel
  • finagle-mux: Cleaned up build information
  • finagle-mux: GC Avoidance primitives
  • finagle-mux: Move exp.MuxClient and exp.MuxServer
  • finagle-mux: Record tracing info when Mux is enabled
  • finagle-mux: Refactor Session to make closing a Session uniform
  • finagle-mux: Render mux clients leasable
  • finagle-redis: Added support for redis MOVE command.
  • finagle-serversets: Reduce the number of intermediate datastructures
  • finagle-thriftmux: Add ThriftMux.withClientId
  • finagle-thriftmux: Maintain legacy client and server names
  • finagle-{core,thrift,mux}: Clean up contexts, delimit Locals


  • finagle-core: Fixed DefaultClient to use the base close method
  • finagle-core: Fix a race condition when closing in DefaultServer
  • finagle-serversets: memoize path parses in ServerSet2
  • finagle-mux: remove references to org.jboss.netty.util.CharsetUtil
  • finagle-http: create HttpTransport in codec
  • finagle-http: fix basic authentication with special characters
  • finagle-http: temporary fix for prematurely expiring streaming responses
  • finagle-core: don’t discard outstanding readq elements in ChannelTransport
  • finagle-core: Add Socks Proxy Authentication support
  • finagle-doc: fix image size in client stack figure.
  • finagle-stats: unregister cumulative gauges when all references have been collected
  • finagle-core: fix truncation in ChannelBufferBuf#slice()
  • finagle-stats: upgrade to the latest version of metrics
  • finagle-stats: Enable cumulative gauges in MetricsStatsReceiver
  • finagle-mysql: Move mysql testing out of finagle-mysql
  • finagle-serversets: serverset namer - synthesize nodes for each endpoint
  • finagle-http: fix HttpClientDispatcher
  • finagle-core: transport should be considered closed if it is failed
  • finagle-core: Improve the failure for cancelled requests in the ClientDispatcher
  • finagle-core: LocalScheduler - add LIFO option
  • finagle-core: don’t join after interrupt in Exitguard.Unguard()
  • finagle-serversets: Replaces Op with Activity Problem
  • finagle-mysql: implement builder using StackClient.
  • finagle-core: Make LoadService not fail if a sub-dir is not readable
  • finagle-core: Make com.twitter.finagle.Name an ADT
  • finagle-core: curry newDispatcher in Stack{Client, Server}
  • finagle-thriftmux: Add a flag for enabling ThriftMux
  • finagle-doc: improved rastering of logos
  • finagle-core: Retry on com.twitter.util.TimeoutException
  • finagle-core: introduce ForkJoinScheduler
  • finagle-serversets: facade for ZooKeeper libraries


  • finagle-*: Add and replace the use of org.jboss.netty.util.CharsetUtil
  • finagle-benchmark: Fix caliper failures due to new guava
  • finagle-core: Disable Monitor usage of in Netty3Listener
  • finagle-core: Enforce usage of c.t.finagle.util.DefaultLogger
  • finagle-core: Fix a Netty3Timer capitalization bug
  • finagle-core: Fixed unresolved promises in client dispatcher
  • finagle-core: Implement ServerBuilder in terms of StackServer.
  • finagle-core: Introduce 2-level caching in the name interpreter
  • finagle-core: Introduce Failure interface (internally)
  • finagle-core: Introduce StackServer
  • finagle-core: Introduce a flag for debug tracing
  • finagle-core: Make StackClient symmetric to StackServer
  • finagle-core: Parse names into trees; introduce separate evaluation.
  • finagle-core: Remove redundant Netty3Timer param def
  • finagle-core: Resolver.resolve throws IllegalArgumentException on logical name
  • finagle-core: RetryPolicy filter, limit, combine
  • finagle-core: Thread through NullReporterFactory in ServerBuilder.
  • finagle-core: Use DefaultLoadBalancerFactory
  • finagle-core: Use JDK6-friendly RuntimeException constructor in Failure
  • finagle-doc: README refresh
  • finagle-doc: Refresh client stack docs
  • finagle-memcached: Ketama memcache: accept weighted addresses
  • finagle-mux: Add server-side Stack wiring for Mux and ThriftMux
  • finagle-mysql: Proper prepared statement support.
  • finagle-serversets: Add Read-Only ZK support to zk2 Resolver
  • finagle-serversets: Zk2: deliver events serially in their own thread
  • finagle-thrift: workaround libthrift TBinaryProtocol.writeBinary bug
  • finagle-zipkin: Include service name in all traces


  • finagle-core: Case insensitive Dtab headers in HTTP codec
  • finagle-core: Introduce Stack.Params#contains
  • finagle-docs: address small style nits
  • finagle-http: support reading params in content body for HTTP methods other than POST and PUT
  • finagle-memcached: add ketamaclient initial readiness before the first request
  • finagle-serversets: Disable retry behavior but turn exception into negative resolution.
  • finagle-serversets: Stabilizer: don’t consider Pending update successful
  • finagle-stats: use java.lang.Double in addGauge()
  • finagle: Add cause Throwables for all ConnectionFailedExceptions
  • finagle: Fix Travis-CI integration.
  • finagle: Swap Stack.Node and Stack.Leaf args in toString formatting
  • finagle: Update 3rdparty library versions
  • finagle: Upgrade birdcage to guava 16
  • finagle: upgrade ostrich to 9.4.2
  • finagle: upgrade util to 6.13.2


  • finagle-core: ForkJoin scheduler: first draft
  • finagle-doc: Update URL to Finagle blog post. Motivation: Outdated URL
  • finagle-http: compress text-like content-types by default
  • finagle-memcached: Mark test “not migrating yet” as flaky
  • finagle-mux: don’t delegate empty dtabs
  • finagle-mysql: Better failure handling for the dispatcher
  • finagle-ostrich4: Make OstrichExporter compatible with Ostrich CommandHandler.
  • finagle-redis: Add SINTER command to redis client
  • finagle-redis: Allow an empty string as a hash field value
  • finagle-redis: Fixed the empty string issue of MBULK_REPLY
  • finagle-serverset: ServerSets2: reset value on SyncConnected
  • finagle-stats: Upgrade metrics dependency to the latest version.
  • finagle-thrift: Do not rely on ThreadLocal’d ClientIds in TTwitterFilter
  • finagle-thrift[mux]: Reintroduce ClientIdContext by default
  • finagle-zipkin: TraceId invariance
  • finagle/S2: introduce address stabilization, stats
  • finagle: Add Mux and ThriftMux Clients based on com.twitter.finagle.Stack
  • finagle: fix dependency problem with multiple version of serversets
  • finagle: Fix the sbt doc generation (and tests)
  • finagle: upgrade Netty to 3.8.1
  • finagle: upgrade ostrich to version 9.4.0
  • finagle: upgrade util to version 6.13.0


  • finagle: release scrooge version 3.12.3
  • finagle-exception: Drop scrooge in favor of pre-generated Thrift Java source code.
  • finagle-zipkin: Drop scrooge in favor of pre-generated Thrift Java source code.


  • finagle: release ostrich version 9.3.1
  • finagle: release util version 6.12.1
  • finagle: Upgrade everyone to the new c.t.common.server-set


  • finagle-core: Add a ServerBuilder.safeBuild(ServiceFactory) method for Java compatibility
  • finagle-core: Add basic Scaladocs for all Filters and Services
  • finagle-core: close Name Var observation on service close
  • finagle-core: com.twitter.finagle.Stack: initial version
  • finagle-core: Fix race condition in server dispatcher draining state machine
  • finagle-core: low hanging fruit
  • finagle-core: Make Resolver.evalLabeled private[finagle]
  • finagle-core: Option to enable thread pool scheduler in finagle”
  • finagle-core: Record Finagle version in tracing information
  • finagle-core: Remove a long-forgotten java file
  • finagle-core: Separate stats scopes for service-creation and request failure
  • finagle-core: TimeoutFactorySpec => TimeoutFactoryTest
  • finagle-core: Users don’t get NPE on directories without permissions
  • finagle-core: Weights, weighted load balancer, memoization
  • finagle-core: Write Throwables.mkString in terms of ArrayBuffer instead of Seq
  • finagle-doc: How do I change my timeouts in the Finagle 6 APIs?
  • finagle-example: Port finagle-example thrift to new style APIs
  • finagle-http: Add Dtab filter in RichHttp
  • finagle-http: enable tracing on finagle 6 http api
  • finagle-kestrel: Fix match-exhaustiveness issue in DecodingToResponse.parseResponse
  • finagle-kestrel: Use Var[Addr] as underlying cluster representation
  • finagle-memcache: Add a parameter to disable host ejection from KetamaFailureAccrualFilter
  • finagle-memcached: include response type for IllegalStateException
  • finagle-mux: Adds lease support to mux clients
  • finagle-mysql: Embeddable MySql support for Unit/Integration Testing in Finagle-MySql
  • finagle-serversets: prevent MatchError when resolving zk path + endpoint
  • finagle-serversets: Use ephemeral ports and Var.sample in tests
  • finagle-serversets: Use the watch method instead of the now deprecated monitor method
  • finagle-tracing /zipkin: remove some allocations
  • finagle: update dependencies com.twitter.common*
  • finagle: update ostrich to 9.3.0
  • finagle: update util to 6.12.0
  • finagle: Use a more descriptive message for when client name resolution is negative


  • finagle-core: Masks cancellation on PipeliningDispatcher
  • finagle-doc: Fix finagle-websocket link on Finagle docs website.
  • finagle-http: Http client dispatcher
  • finagle-kestrel: Add abort command to kestrel client


  • finagle-core: Add a “tries” scoped StatsFilter to ClientBuilder.
  • finagle-core: Allow clean shutdown for insoluble address in DelayedFactory.
  • finagle-core: Better exception message for resolver not found issue.
  • finagle-core: Introduce P2CLB: O(1), fair-weighted, concurrent load balancer
  • finagle-core: Refactor dispatchers.
  • finagle-core: Set interest ops when reading in ChannelTransport.
  • finagle-core: Skip hostStatsReceiver rollup if it’s null in DefaultClient.
  • finagle-core: Untyped ChannelTransports.
  • finagle-example: Use new request.headers() Netty API.
  • finagle-http: Proper streaming dispatch.
  • finagle-kestrel: Make ReadHandle an abstract class for better Java compatibility.
  • finagle-serversets: Fix com.twitter.common.zookeeper.server-set dependency discrepancy.
  • finagle-serversets: Introduce ServerSet2.
  • finagle-serversets: Weight/priority vectors in ServerSet2.
  • finagle-stream: Use dispatch logic.
  • finagle-stress: Use BridgedThreadPoolScheduler.
  • finagle-thrift: Add TFinagleBinaryProtocol
  • finagle-thriftmux: Drop dependency on finagle-ostrich4.
  • finagle-thriftmux: Remove scrooge2 dependency.
  • finagle: Use Future.before.
  • finagle: adds a section to the FAQ explaining the com.twitter.common situation.
  • finagle: s/setValue(())/setDone()/g


  • finagle-core: Fix ServiceTimeoutException naming.
  • finagle-core: Increase default tcpConnectTimeout to 350ms.
  • finagle-core: Remove memory leak for never satisfied promises in DelayedFactory.
  • finagle-memcached: Add ClientBuilder APIs that use Name instead of Group.
  • finagle: Daemonize threads in ClientBuilders used in finagle.


  • finagle-core: Avoid creating a new ‘NoStacktrace’ array for each exception.
  • finagle-core: Better support for negative Addr resolution in StabilizingAddr.
  • finagle-core: Make Dtab.base changeable.
  • finagle-core: Move mask cancel filter over to Future#mask.
  • finagle-exp: New warmup filter.
  • finagle-ostrich4: Deprecate Netty methods.
  • finagle-serversets: Better handling of permission exceptions in ZkResolver.
  • finagle-testers: Small latency evaluation framework.
  • finagle: Adhere to scala 2.10 pattern matching strictness.


  • finagle: Upgrade ostrich to 9.2.1
  • finagle: Upgarde util to 6.8.1
  • finagle: Upgarde scrooge to 3.11.1


  • finagle-serversets: Higher fidelity addrs from ZK We do the best we can with the current server set implementation.
  • finagle-mysql: better type support
  • finagle-http: Allow Integer to extract negative number
  • finagle-redis: Decode nested multi-bulk replies
  • finagle-redis: Allow expirations in the past
  • finagle-core: bump Netty to 3.8.0.Final
  • finagle: Return empty string when resolving an unlabeled address
  • finagle: Don’t re-scope StatsReceivers per request failure
  • finagle-thrift: Unconditionally set TraceId and ClientId on servers
  • finagle-core: Take -com.twitter.server.serversetZkHosts flag (for tunnelling)
  • finagle-native: tomcat-native-1.1.27
  • finagle-mysql: fix readLengthCodedBinary to read longs
  • finagle-testers: library for integration testing of finagle services
  • finagle: scaladoc warning cleanup
  • finagle-doc: documented all of the stats in finagle-core
  • finagle-serversets: bump server-set dependency to 1.0.56
  • finagle-stats: adds a cautious registration to HttpMuxer / adds a default metrics endpoint to twitter-server
  • finagle-core: verifies that statsfilter has the correct behavior
  • finagle-serversets: Add support for parsing a !shardId on the end of a serverset address
  • finagle-http: Use Reader for streaming
  • finagle-core: no longer makes an anonymous exception in DefaultClient
  • finagle-core: Using system class loader does not work when run inside sbt
  • finagle-core: add pool_num_waited counter to WatermarkPool
  • finagle-core: Protocol support for Wily: HTTP, thrift, mux (& thus thriftmux).
  • finagle-core: respect standard socksProxyHost / socksProxyPort properties in ClientBuilder and Netty3Transporter default args
  • finagle-core: buffers requests until Var[Addr] is in a ready state
  • finagle-core: Add putLong and getLong functions to util.ByteArrays
  • finagle-core: don’t blow up if we don’t have a resolvable host name
  • finagle-core: rm allocation in RichChannelFuture.apply’s operationComplete
  • finagle-core: remove Var.apply; introduce Var.sample
  • finagle-thriftmux: Support ClientIds at the protocol level
  • finagle-kestrel: memory allocation improvements
  • finagle-http: allow PUT requests to use RequestParamMap.postParams
  • finagle-memcached: more performance and less allocations in Decoder


  • finagle-core: Fail ChannelTransport read queue before closing the connection
  • finagle-mux: Add session for mux message passing and bidirectional RPC
  • finagle-zipkin: Depend on scrooge-core instead of scrooge-runtime


  • finagle-core: LoadService: skip empty lines
  • finagle-core: Improve GC profile of Var and Group
  • finagle-core: added a simple defaultpool test to show how it works + more docs
  • finagle-core: removes commented out casting filter
  • finagle-mysql: move protocol into a dispatcher and port to new style apis.


  • finagle-*: Tagging various tests as flaky
  • finagle-*: Fix and reenable some formerly-flaky tests Now that Time.withXXXX is threadsafe
  • finagle-*: Move Var to util
  • finagle-*: Provide generic request contexts
  • finagle-*: Use scrooge3 and up-to-date scrooge-maven-plugin settings
  • finagle-*: upgrade Netty to 3.7.0.Final
  • finagle-core: Add UnwritableChannel stat to ChannelStatsHandler
  • finagle-core: Add a test for Proc exception-swallowing
  • finagle-core: Better interface for RetryPolicy
  • finagle-core: Ensure FIFO ordering when delivering updates to StabilizingGroup
  • finagle-core: Export a health stat in StabilizingGroup
  • finagle-core: Fix a race condition in ListeningSever.announce and don’t announce
  • finagle-core: Fix sourcing for SourcedExceptions
  • finagle-core: Group: communicate via Var[Set[T]]
  • finagle-core: Improve HeapBalancer req distribution when N=2
  • finagle-core: Introduce staged names
  • finagle-core: Let the number of cores be specified on the command line
  • finagle-core: Make socket writable duration stats more useful
  • finagle-core: Migrate RetryingFilter tests from specs to scalatest
  • finagle-core: Move the connections gauge into ChannelStatsHandler for GC
  • finagle-core: Reuse a single exception instance in ServerDispatcher
  • finagle-core: Update com.twitter.finagle package documentation
  • finagle-doc: Add Client/Server Anatomy to docs
  • finagle-doc: Link to “Your Server as a Function”
  • finagle-http: Proper CORS implementation on Finagle
  • finagle-http: SPNEGO http auth (for Kerberos) with an example implementation for internal services
  • finagle-memcached: Exclude CancelledRequestException and CancelledConectionException or cache client failure accrual
  • finagle-memcached: Read key remapping config from ZooKeeper
  • finagle-memcached: ZK based cache node group implementation
  • finagle-redis: SRandMember, send command without count when None
  • finagle-serversets: Mark ZookeeperServerSetCluster as deprecated
  • finagle-thrift: Add a request context for ClientId
  • finagle-thrift: Set the client id in thriftmux


Release process failed. Rolled forward to 6.7.1.


  • finagle-core: Configurable loadBalancer for ClientConfig
  • finagle-core: Fix the memory leak due to the GlobalStatsReceiver
  • finagle-core: Inet util, bind to all if no host is provided
  • finagle-core: Make Future.never a val instead of a def
  • finagle-memcached: Fix tracing ClientRecv timestamp
  • finagle: New ostrich version


  • finagle-core: Add a RetryPolicy constant for retrying on ChannelClosedExceptions.
  • finagle-core: ChannelSnooper: Print exceptions via Logger
  • finagle-core: Finagle client/server APIs: s/target/addr/g
  • finagle-core: Introduce swappable schedulers, ThreadPool scheduler.
  • finagle-core: Replacing ostrich-specific Stats with StatsReceiver interface
  • finagle-core: Tests for BroadcastStatsReceiver
  • finagle-core: adding service name to a service exception
  • finagle-core: fix file mispelling for StabilizingGroup.scala
  • finagle-core: fix memory leak in Group#fromCluster
  • finagle-core: refactor use of InetSocketAddress group and deprecate use of cluster in cache client
  • finagle-http: Add Access-Control-Expose-Headers to Finagle CORSFilter
  • finagle-http: Fix Path comments, improve sbt definition
  • finagle-http: Http connection manager: close synchronously
  • finagle-http: Make behavior of HttpMuxer match its javadoc
  • finagle-http: Mix in Proxy with HttpMessageProxy
  • finagle-http: bump request/response sizes to 5 megs
  • finagle-memcached: Memcached Ketama Client Builder: Add group support that is compatible with oldlibmemcached , creates CacheNodes with ipAddress instead of hostname.
  • finagle-memcached: Update jackson to 2.2.2
  • finagle-memcached: allow custom key in ketama client
  • finagle-memcached: better exception messages for invalid keys
  • finagle-memcached: migration client
  • finagle-ostrich4: improve perf of Counter and Stat
  • finagle-swift: experimental swift-based thrift server and client An experimental annotation based proxy and dispatcher for thrift, using Facebook???s swift for serialization.
  • finagle-thrift: breaking out finagle, higher-kinded-type interface
  • finagle-thrift: fix finagle-thrift rich to work with scrooge 3.6.0
  • finagle-thrift: move scrooge-runtime to scrooge
  • finagle-thrift: remove use of deprecated generated ostrich ThriftServer
  • finagle-zipkin: Add newlines to scribe message
  • finagle-zipkin: Use better metric names for error stats
  • finagle-zipkin: optimize scribe logging to not need slf4j


  • finagle-ostrich4: set stats export URI to stats.json
  • finagle-core: Introduce StabilizingGroup which cautiously removes items from a Group
  • finagle-core: Add group method to ClientBuilder
  • finagle-core: Add service/client name to ServiceTimeoutException
  • finagle-mux: Don’t allocate headers via direct buffers
  • finagle-http: Implement missing modifiers in Http case class
  • finagle-memcache: added support for twemcache commands


  • finagle-http: Move routing by path and method function to RoutingService
  • finagle-redis: Switching from Strings to ChannelBuffers for Scored Zrange commands
  • finagle-stats: Upgrade metrics to 0.0.9
  • finagle-stream: Revert “Stream interface (i.e. chunked) for HTTP message bodies”
  • finagle: Fix documentation about Java & Future
  • finagle: Refresh OWNERS/GROUPS in all subdirectories
  • finagle: Upgrade Netty version to 3.6.6.Final
  • finagle: Upgrade ostrich version to 9.1.2
  • finagle: Upgrade util version to 6.3.7
  • finagle-redis: Implement new SET syntax introduced in redis 2.6.12
  • finagle-core: Open connection threshold et al


  • finagle-core: fix a bug in Trace.unwind in ruby
  • finagle-core: speed up tracing when a trace is unsampled.
  • finagle-redis: implement PEXPIRE/PEXPIREAT/PTTL
  • finagle-redis: Make the multiple argument version of zAdd a separate method.
  • finagle-serverset: create a ZkAnnouncer
  • finagle-thriftmux: make thriftmux server back compatible with thrift framed codec
  • finagle-zipkin: Performance improvement for finagle-zipkin
  • finagle: Gizzard: Some followup deps alignment to fix deployment classpath issues
  • finagle-memcached: KetamaClient based on finagle-6 API
  • finagle-exception: unique namespace for scribe
  • finagle-thrift: Add scrooge3 support
  • finagle: bump sbt util/finagle version
  • finagle: Updating owner list
  • finagle: Upgrade util to 6.3.6 and scrooge-runtime to 3.1.2


  • finagle-http: CookieMap instead of CookieSet
  • finagle-memcached: remove items stats test since twemcache does not carry those
  • finagle-http: don’t choke on HEAD requests
  • finagle-core: ReusingPool: fix race between setting Future.never and initiating connect
  • finagle-thriftmux: also release services
  • finagle-http: Use the correct dispatcher for RichHttp and new API
  • finagle-exception: a loadable exception reporter
  • finagle-core: make global flags consistently camelCase
  • finagel-http: enable tracing by default for Http
  • finagle-http: Call super method only if response is not chunked
  • finagle-core: Tracing changes to annotate both client and server ip addresses
  • finagle-http: Stream interface (i.e. chunked) for HTTP message bodies
  • finagle-core: get a resolver instance contained in the main Resolver
  • finagle-mux: fix TagMap.iterator
  • finagle-mdns: Adding project to sbt
  • inagle: Fix doc
  • finagle-mysql: refactor endec into proper fsm
  • finagle: Update sbt project for (util, ostrich, finagle)


  • finagle-core: Add unmanaged cache pool cluster
  • finagle-core: Always enable TracingFilter even when no tracers are used.
  • finagle-core: cache the cancelled connections in WatermarkPool instead of CachingPool
  • finagle-core: Fix behavior of proxy forwarding in StatsReceiver
  • finagle-core: Fix usage of RollupStatsReceiver in StatsFactoryWrapper.
  • finagle-core: Generalize LoggingFilter
  • finagle-core: HeapBalancer: fix handling of unavailable nodes
  • finagle-core: Properly synchronize concurrent access to ProxyService state.
  • finagle-core: Refactor Heapbalancer, remove usage of per host statsReceiver.
  • finagle-core: share worker pools between server and client
  • finagle-exception: Fix sourceHost supplied to chickadee exception reporter
  • finagle-http: Add HttpConnectHandler and HttpClientCodec in the correct order when setting up an HTTP proxy client.
  • finagle-http: add Response(status)
  • finagle-http: EncodeBytes/decodeBytes for Request
  • finagle-http: Refactor HeaderMap/ParamMap
  • finagle-memcache: change to use consistent way to provide failure accrual params
  • finagle-memcached: Propagating error message from server to client
  • finagle-memcached: support for configuring numReps in KetamaClientBuilder
  • finagle-mux: convert tests to use ScalaTest
  • finagle-mysql: Ability to deal with non-ascii utf-8 characters
  • finagle-mysql: Add ability to pass StatsReceiver to builder
  • finagle-mysql: adds support for latin1_bin, paves the way for more charsets.
  • finagle-mysql: Encode all the given the error information in the ServerError
  • finagle-mysql: Fix improper use of ServiceFactory in Client
  • finagle-redis: Fix byte encoding problem with Z(Rev)Rank
  • finagle-redis: fixing Nil values in MBulkReplies
  • Finagle-zipkin: decoupled sampling logic from ZipkinTracer to make a reusable SamplingTracer
  • finagle-zipkin: Improve zipkin trace sampling
  • finagle-zipkin: make ZipkinTracer loadable
  • finagle: Document metrics
  • finagle: Force service loader to return a concrete collection
  • finagle: Refactor Future#get to Await.result
  • finagle: Upgrade jackson to 1.9.11
  • finagle: Upgrade ostrich to 9.1.1
  • finagle: Upgrade util to 6.3.4


  • finagle: Upgrade util to 6.3.0
  • finagle-thrift: SocketAddress when serving an iface
  • finagle-core: Specify DefaultTimer when creating a ChannelFactory
  • finagle-core: DefaultClient/Server: Do not add TracingFilter if NullTracer is used


  • finagle-zipkin: tracing improvements
  • finagle: Upgrade util to 6.2.5


  • finagle-core: Add BroadcastCounter and BroadcastStat, refactor Broadcast and Rollup Receiver.
  • finagle: update sbt, add finagle-exp
  • finagle-doc: Add a FAQ, add an entry about CancelledRequestExceptions
  • finagle-core: Add client support for proxies that support HTTP CONNECT, such as squid.
  • finagle-doc: A few wording fixes in Sphinx doc templates.
  • finagle-core: StatsFilter: Check for WriteException-wrapped backup-request losers
  • finagle-mysql: bug fixes
  • finagle: Update sbt project definition
  • finagle-core: Introduce DefaultTracer that load available Tracers via LoadService + Fix equality with NullStatsReceiver
  • finagle-core: CachingPool: Do not schedule timer tasks if ttl is Duration.Top


Released 2013/03/21

  • finagle: Fix flakey tests
  • finagle: fix sbt build
  • finagle: Upgrade util to 6.2.4
  • finagle-core: Fix reporting bug for pending reqs
  • finagle-core: Move Disposable/Managed to util
  • finagle-core: Use Future.Nil
  • finagle-doc: Improve, add Matt Ho’s talk.
  • finagle-exp: Add BackupRequestFilter, new backup request filter using response latency quantiles
  • finagle-http: Avoid URISyntaxException
  • finagle-memcached: Add Replication Cache Client
  • finagle-mysql: Make prepareAndExecute and prepareAndSelect useful again.
  • finagle-mysql: Make sure we are properly managing prepared statement
  • finagle-mysql: Move interfaces outside of protocol package
  • finagle-redis: Moved redis server classes from private to public
  • finagle-thrift: fix 2.10 build


Released 2013/03/12

  • doc: Finagle user guide!
  • finagle: Remove finagle’s dependence on jerkson.
  • finagle: Upgrade Netty to 3.5.12
  • finagle: Upgrade scrooge-runtime to 2.4.0
  • finagle: Upgrade util to 6.2.2
  • finagle-core: com.twitter.finagle.Group: introduce names, use them.
  • finagle-core: deprivatize, document Client, Server.
  • finagle-core: fix multiple stats bugs.
  • finagle-core: Log Finagle’s version number on startup.
  • finagle-core: RetryingFilter, don’t retry on CancelledRequestException.
  • finagle-http: New Request object queryString utility functions.
  • finagle-http: New Request/Response encode/decode functions.
  • finagle-memcached: Actively reestablish zk connection whenever disconnected or expired.
  • finagle-memcached: Cache pool cluster not updated since 2nd serverset change.
  • finagle-memcached: Don’t use deprecated FuturePool.defaultPool.
  • finagle-mysql: Add project in the list of deployed jar.
  • finagle-mysql: Fix race condition in the authentication process.
  • finagle-mysql: Move it to experimental package.
  • finagle-ostrich4: Add OstrichExporter to enable Ostrich stats in the new App stack.
  • finagle-redis: Add support for INFO command.
  • finagle-resolver: additional visibility for Announcers and Resolvers.
  • finagle-zipkin: new factory methods.


Released 2013/01/30

  • finagle: update util and ostrich dependencies
  • finagle: libraries: preliminary 2.10 port/build
  • finagle: Tracer use new daemon() flag; get rid of factory. Simplify.
  • finagle: refactor clients and servers to be simpler, more logical.
  • finagle-core: Provide a reportHostStatsTo API on ClientBuilder that per-host stats will be reported to.
  • finagle-core: Use Groups in place of Clusters
  • finagle-core: Create a NonShrinkingCluster
  • finagle-redis: made zRange… commands work more like the actual redis commands
  • finagle-stats: new project that provides a StatsReceiver based on Twitter’s Metrics library.
  • finagle-http: add new-style client and server, including a primitive URL fetcher


Released 2013/01/22

  • finagle-core: basic SOCKS support for finagle clients, intended for use with ssh -D.


Released 2013/01/22

  • finagle-core: CachingPool owns connections and caches them even if upstream cancels
  • finagle-core: Eliminate varargs overhead in StatsReceiver.time and timeFuture
  • finagle-core: LoadBalancerTest: allow the tests to be run with Google Caliper
  • finagle-core: make snap on mapped cluster thread-safe
  • finagle-memcached: explicitly pass in initial cache nodes when using a a static cluster
  • finagle-native: fix up grab_and_path_tomcat_native
  • finagle-redis: finagle redis btree sorted set commands
  • finagle-redis: Implemented redis HMSET
  • finagle-redis: expireAt command


Released 2012/12/18

  • finagle-mux: new session protocol
  • documentation: document connection management and associated configuration options
  • finagle-core: expose newChannelTransport in Codec to allow multiplexing in clients
  • finagle-http RequestProxy: proxy response


Released 2012/12/11

  • TimerSpec, RefcountedSpec: make deterministic
  • finagle-core: JSSE SSL support for intermediate certificates
  • finagle-core: push SSLEngine all the way up to the ServerBuilder
  • finagle-core: preclude default SourceMonitor in clients
  • finagle-core: ReusingPool for pipelined, multiplexed clients
  • finagle-core: remove wasteful RichLong allocations in hot path
  • finagle-core: move acquire/release of services outside of WatermarkPool’s synchronization
  • finagle-core: remove unintended reflection-by-refinement-type
  • finagle-thrift: actually support multiple protocols
  • finagle-ostrich4: configurable delimiter
  • finagle-redis: parse case-insensitive commands


Released 2012/11/26


Released 2012/11/26

  • util 6.0.0 dependency
  • finagle-core: new client/server APIs; not yet exposed to users


Released 2012/11/21

  • finagle-spdy: new codec
  • finagle-core: ServiceTimeoutException is now a WriteException (so they can be retried)
  • finagle-core: close channels owned by ChannelTransport before failing queues
  • finagle-core: share ChannelStatsHandler in clients and servers to avoid excessive stats-related weakrefs
  • finagle-core: don’t leak Spooled updates in the HeapBalancer


Released 2012/11/08

  • finagle-redis: String commands
  • finagle-redis: collection.Set => collection.immutable.Set per #116
  • finagle-thrift: SeqIdFilter: Don’t modify thrift requests.
  • BackupRequestFilter: experimental service filter to perform backup requests


Released 2012/10/26

  • finagle-redis: fix zrevrangebyscore (
  • finagle-memcached: fix space leak when using clustering
  • finagle-core: special case 1-hosted (static) clients to bypass loadbalancer
  • finagle-core: Introduce an experimental buffer-based pool


Released 2012/10/16

  • Upgrade ostrich to 8.2.9
  • Upgrade util to 5.3.13
  • Upgrading slf4j to 1.6.1
  • finagle: Rm usage of deprecated Predef.error.
  • finagle-core: Changed stats name in ChannelStatsHandler from exception msg to getClass.getName
  • finagle-core: Add counters to track disconnections due to Idle activity (both read/write)
  • finagle-core: Add “adds”/”removes” counters in HeapBalancer to track modifications
  • finagle-core: Added name to HeapBalancer init (via exception) if HB size is 0
  • finagle-core: Don’t log dropped events: they are actually quite numerous.
  • finagle-kestrel: Disable failFast for kestrel.
  • finagle-memcached: Cluster support within finagle-memcached (phase 2)
  • finagle-redis: added new commands


Released 2012/09/27

  • Doc: update README with working thrift Java example
  • Doc: fix compile errors in examples
  • finagle-http: fix typo in RequestBuilder API
  • finagle-stress: FrontEndServerStress refactor; now generates runnable binary
  • finagle-core: add optional shouldRetry argument to RetryPolicy.tries
  • finagle-core: pools propagate underlying availability correctly
  • finagle-core: move fail-fast before the pool. This prevents it from masking errors from the failure accrual mechanism, and is arguably the “correct” placement
  • finagle-core: fix argument type in RetryingFilter.apply
  • finagle-core: failFast by default; disable for Kestrel
  • finagle-memcached: cache-pool specific Cluster implementation
  • finagle-memcached: add stat to cache-pool cluster
  • finagle-redis: add scan, hscan commands
  • finagle-redis: add list commands


Released 2012/09/07

  • finagle: Update/fix README
  • finagle: Upgrade util to 5.3.10
  • finagle: Update guava to v13
  • finagle-redis: API v2 + update example
  • finagle-thrift: validate connections based on TApplicationException
  • finagle-core: SSL: fix connection failure propagation in futures



  • finagle-core: Upgrade to Netty 3.5.5


Released 2012/08/24

  • Doc: Fix mistake in finagLe README that claimed Future objects have a getContentAsync method
  • Doc: Fix typos in README
  • finagle-thrift: ThriftChannelBufferDecoder: fix for composite buffers
  • finagle-mysql: MySQL codec from Ruben Oanta.
  • finagle-core: add isSuccess to FailureAccrualFactory
  • finagle-http: Fix file extension bug in finagle-http


Released 2012/06/17

  • Doc: Typos
  • finagle-core: fix canceling recurring timers
  • finagle: kill finagle-memcached-hadoop
  • finagle-memcached: in-process memcache server now supports expiry
  • finagle-memcached: Adding key length validation and refactor validation logic.


Released 2012/08/10

  • finagle-core: Fixed stats visibility
  • finagle-serversets: allow specification of an additional endpoint name in ZookeeperServerSetCluster
  • finagle-serversets: ZookeeperServerSetCluster.join now return an EndpointStatus + Named/Daemonized init thread
  • finagle-core: Changed Cache’s internal implementation from queue to deque (to allow LIFO behavior)
  • finagle-core: cluster initialization honors global timeout in ClientBuilder.
  • finagle-stress: finagle: kill obsolete benchmark


Released 2012/08/02

  • finagle: patch public release of OSS libraries; catch up sbt
  • finagle-core: netty 3.5.3.Final
  • finagle-core: Timer: address review comments, fix tiny race


Released 2012/07/31

  • finagle-core: Timer: dispose timeouts on cancellation


Released 2012/07/31

  • finagle-core: Fix critical bug in Timer by refactoring the Timer model
  • finagle: Add OWNERS file to finagle-memcached, finagle-redis
  • finagle-redis: add keys and hkeys
  • finagle-zipkin: Add a debug flag, add an i64 bit field to the thrift request header struct and as a http header
  • finagle-core: SourceTrackingMonitor to report whether it’s in client or server
  • finagle-zipkin: Add duration to the the JVM gc annotation.


Released 2012/07/20

  • finagle-serversets: Use authenticated zookeeper client suggested for new SD cluster migration
  • finagle-thrift: seqid filter: improved tests
  • finagle-zipkin: Add duration to annotations for timing operations
  • finagle-serversets: bump up server-set version to 1.0.10 (latest) in finagle-serversets


Released 2012/06/25

  • finagle-core: ClientBuilder and ServerBuilder’s MonitorFilter to report exception sources
  • finagle-test: Add TaskTrackingTimer benchmark
  • finagle-thrift: SeqIdFilter: helpful exceptions
  • Dispatcher: all write exceptions are wrapped with WriteException


Released 2012/06/14

  • finagle: Upgrade util to 5.2.0, ostrich to 8.1.0
  • finagle-redis: extend codec
  • finagle-memcache: first phase of serverset support
  • finagle-b3: we are using zipkin now
  • finagle-kestrel: Kill com.twitter.concurrent.Channel
  • finagle-core: JvmFiler, trace jvm events


Released 2012/06/01

  • finagle-core: Refactor the new way of managing resources
  • finagle-core: Add capability to drain dispatcher on expire
  • finagle-core: ZookeeperServersetCluster notify client when underlying Cluster is ready
  • finagle-exception: Upgrade jerkson to 0.5.0 and streamyj to 0.4.1


Released 2012/05/25

  • Upgrade to scala 2.9.2
  • finagle-core: FailFast, do not admit requests when marked failed
  • finagle-redis: now return tuples and doubles
  • finagle-memcached: record client recv annotation after hit/miss
  • finagle-core: expand exception chain in StatsFilter


Released 2012/05/08

  • http: add AddResponseHeadersFilter, CorsFilter
  • finagle-redis: Add ZCard, ZRem, ZRevRange, ZRevRangeByScore commands
  • finagle-memcached: Added b3 annotations for key hits/misses
  • finagle-memcached: getResult/getsResult for java
  • finagle-http: fix client codec
  • HeapBalancer: close services that are removed from cluster
  • finagle-redis: add tracing and stats support
  • finagle-http: Add the client address for http traces. Also record uri after service name has been set
  • finagle-memcached: more efficient implementation of GetResult.merged
  • finagle-redis: return pairs for hgetall, zrangebyscores, zrevrangebyscores cmds
  • finagle-core: introduce Transports and Dispatchers
  • tracing: annotate client connection when tracing
  • update to netty 3.4.1.Final
  • prevent tenuring of response objects for responses from previously idle connections
  • finagle-redis: add quit command
  • finagle-http: add service multiplexer
  • friendlier java interface for retries


Released 2012/03/14

  • ServiceToChannelHandler: keep track of shutdowns with pending replies, don’t monitor errors that occur after cancellation.
  • Add two received_bytesm sent_bytes to per-channel stats.
  • http: Add wwwAuthenticate(=) and isXmlHttpRequest
  • http: CancelledRequestExceptions become 499s
  • clients: experimental Fail-Fast mode (ClientBuilder.expFailFast(true))
  • b3: Only log that a span was unfinished if we actually found one
  • thrift: better support for one-way calls
  • server: option for cancellation on hangup (default=true)
  • codecs: improved support for multiplexed protocols
  • upgrade to netty 3.4.0.alpha1 which fixes connect timer resolution issues. Trustin says this should be as stable as 3.3.1.Final
  • serversets: allow for additional endpoints
  • tests: use true ephemeral ports instead of RandomSocket
  • memcache stress: use new command line flag library from commons
  • thrift: concatenate arrays with System.arraycopy
  • memached: fix bug wherein we made requests with empty keys on retries


Released 2012/03/01

  • commons-stats: memoize counters
  • cluster: don’t reuse adds; keep many values per key
  • clientbuilder: buffer handlers to avoid deadlock


Released 2012/02/27

  • unify client and server factories
  • memcache stress test: one connection per process
  • b3: make tests deterministic
  • upgrade to newest util (and to Guava r11)


Released 2012/02/15

  • HeapBalancer: safely remove services from cluster when they have requests in flight
  • http: speed up logging
  • core: keep track of handler walltimes


Released 2012/02/13

  • finagle-redis: publish.
  • http: Message.mediaType=: no longer sets charset to utf-8
  • http: Message.setContentType: defaults charset to utf-8
  • http: added Message.charset, Message.charset=
  • Refactor resource management inside of the builders, making lifetimes explicit
  • Generic cluster API, support in the HeapBalancer for dynamic hosts list; remove other load balancers
  • redis: memcache.Client-style interface
  • netty: update to 3.3.1.Final, and add NPN TLS extension support
  • b3: flush span if timeout occurs
  • b3: java friendly tracer API
  • stress/example: “topo”, a minimal appserver-like topology for testing
  • memcache: tunable example for benchmarking, testing
  • ServerBuilder: major refactor & simplification
  • SummarizingStatsReceiver: fix bug where sort didn’t operate over a stable collection


Released 2012/01/24

  • http: Message.withX methods now have parameterized return types
  • memcached: (Ketama) host ejection
  • Noisier, more robust monitoring.
  • zk cluster: avoid potential infinite loop
  • http streaming: better detection, handling of dead channels
  • http: always encode output as UTF-8
  • stream: use offer/broker for duplex stream
  • redis: imported finagle redis client from Tumblr. not yet published.


Released 2012/01/05

  • SSLEngine: do not reuse between connections
  • ServerBuilder.Server: localAddress to get ephemeral port values
  • More detailed client stats
  • kestrel: parse parseStatsLines
  • FailFastFactory: new fast-fail strategy with maxOutstandingConnections
  • exceptions: add peer information to connection failures, add service name to all exceptions
  • fixes: space leak in stats, ReliableDuplexFilter lazy load ordering
  • b3: allow the user to specify sample rate
  • exception reporter: share scribe connection across instances
  • finagle-ostrich: remove, it’s obsoleted by finagle-ostrich4


Released 2011/12/02

  • update to util 1.12.7


Released 2011/12/01

  • update to util 1.12.6


Released 2011/11/30

  • upgrade to netty 3.2.7.Final
  • streaming: support HTTP/1.0
  • native: fix content-length header


Released 2011/11/29

  • http: Propagate CancelledRequestException rather than continuing
  • thrift: deprecated LookupContext, using finagle.thrift.ClientId
  • use monitors where applicable (composable widgets for handling exceptions)
  • memcache: PHPMemCacheClient
  • make RetryingFilter usable from Java
  • thrift: convert uncaught application exceptions into TApplicationExceptions on the wire
  • NoStacktrace.getStackTrace() returns non-empty stacktrace array
  • kill off openConnectionsHealthThresholds (unused)


Released 2011/11/08

  • SSL: make native provider bootstrapping code work; refactor ‘Ssl’ singleton
  • tracing: Update configurations and libraries to use tracer factory introduced to make it possible to release resources properly in tracers
  • finagle-thrift: connection options + client id
  • a more flexible retry filter


Released 2011/11/04

  • ExpiringService: add stats for idle and lifetime expiration. Deactivate() regardless of latch counter
  • Filters: don’t apply refcounts on composition, do it only (and always) in the builder
  • Count pending timeouts, and export them
  • ChannelService: release services when prepareChannel fails. This fixes a connection leak
  • WatermarkPool: flush waiters on creation failure. This fixes a condition wherein we’d keep waiters unnecessarily.
  • Timeout exceptions: include service name
  • Suppress excessive logging of the exceptions that mostly caused by unreliable client connections.
  • memcached: Add generic type support (via Client.adapt), and Array[Byte] and String instances
  • finagle-stream: do not admit concurrent requests
  • Tracing: Add release method to Tracer trait, add tracerFactory to builders, deprecate tracer on builders


Released 2011/10/24

  • Service: response Future will now be cancelled if the client disconnects
  • use static exceptions for TimedOutRequestException
  • kestrel: Cancel request Future on close in kestrel ReadHandle
  • exception cleanup: wrap all Channel exceptions with their underlying exception. This makes UnknownChannelExceptions in particular easier to debug
  • Friendlier exceptions: In order to give very specific error messages to timeouts in finagle (so beginners know which settings in the client and server builder caused them), I’m adding lots of human-readable messages to the various TimeoutExceptions.
  • some timer bug fixes, particularly: TimerToNettyTimer: actually cancel underlying task.


Released 2011/10/14

  • tracing: Change SpanId to use RichU64String
  • tracing: Trace.{enable,disable}
  • http: http.RequestBuilder
  • http: add common media types


Released 2011/09/28

  • memcached: new interface for partial results (ie. retrieval failures + successes)
  • tracing: set service name in the endpoint instead of the span
  • more idiomatic KetamaClientBuilder constructor
  • tracing: convenience methods to add binary annotations
  • finagle-http: misc. fixes
  • HeapBalancer - a new lg n load balancer (asymptotically more efficient!)
  • upgrade to ostrich 4.9.0


Released 2011/08/29

  • http: new http library


Released 2011/08/23

  • tracing: fixed space leak
  • ssl: integrate openssl sslengine
  • thrift: update to sbt-thrift 2.0.1
  • stream: always release server when we close
  • serversets: upgraded to guava-r09
  • core: expose stats on failed retries


Released 2011/08/12

  • thrift: add a server-side buffered codec; fix tracing issue in buffered codec
  • http: workaround hole in netty logic to guarantee maxRequestSize
  • serversets: don’t block on ClientBuilder construction
  • ostrich4: update to ostrich 4.8.2
  • streaming: reimplement HTTP chunked streaming in terms of offer/broker
  • kestrel: buffered & merging of ReadHandles


Released 2011/08/05

  • upgrade to netty 3.2.5.Final
  • kestrel: fix visibility of ResultWithCAS
  • kestrel: Client.{read,write}, Client.readReliably, MultiReader: suite of kestrel streaming readers (including grabby-hands replacements) using Offer/Broker
  • kestrel: don’t render timeouts > 2^31-1
  • tracing: fix sampling bug
  • tracing: trace the kestrel client
  • quench unecessary error reporting


Released 2011/08/02

  • SSL: perform hostname validation in the client. this is the reason for the minor bump: we change the .tls() ClientBuilder signature
  • introduce util-codec dependency for use of the apache commons base 64 codec


Released 2011/07/29

  • make it easier to use the NullStatsReceiver from java
  • convert WriteException to a case class (github issue 25)
  • add _root_. to java.util.Map import. reorder imports
  • Upgrade finagle-common-stats to twitter-common-stats 0.0.16
  • encode more HTTP codec errors
  • adding cardinality to ServiceException
  • finagle CachingPool: limit size to highWatermark - lowWatermark
  • exception reporting: gzipping trace strings
  • set ostrich version of finagle-ostrich4 to 4.7.3
  • ChannelServiceFactory: encode exceptions from bootstrap.connect()


Released 2011/07/22

  • http: convert codec exceptions into 4xx errors; report them as such upstream
  • memcache: gets and cas support.


Released 2011/07/19

  • fix: 1.7.2 introduced a regression in the pool that may, under certain circumstances, admit connections beyond the high watermark.
  • quench exception for setting multiple Promise values when racing with write errors.
  • Adds tracing support for the Memcached client. This only creates the client side annotations, no support for passing along ids and such to the memcached server.


Released 2011/07/18

  • support end-to-end cancellation in finagle clients; fixes possible pool starvation conditions, and allows clients to cancel requests and reclaim resources
  • end-to-end timeouts: introduce, .connectTimeout and .timeout. .connectTimeout is the end-to-end connection timeout (includes acquisition & TCP time), .timeout is an end-to-end request time: no requests will take longer
  • some doc fixes
  • misc. bug fixes