Packages

  • package root
    Definition Classes
    root
  • package com
    Definition Classes
    root
  • package twitter

    Start with com.twitter.finagle.

    Definition Classes
    com
  • package finagle

    Finagle is an extensible RPC system.

    Finagle is an extensible RPC system.

    Services are represented by class com.twitter.finagle.Service. Clients make use of com.twitter.finagle.Service objects while servers implement them.

    Finagle contains a number of protocol implementations; each of these implement Client and/or com.twitter.finagle.Server. For example, Finagle's HTTP implementation, com.twitter.finagle.Http (in package finagle-http), exposes both.

    Thus a simple HTTP server is built like this:

    import com.twitter.finagle.{Http, Service}
    import com.twitter.finagle.http.{Request, Response}
    import com.twitter.util.{Await, Future}
    
    val service = new Service[Request, Response] {
      def apply(req: Request): Future[Response] =
        Future.value(Response())
    }
    val server = Http.server.serve(":8080", service)
    Await.ready(server)

    We first define a service to which requests are dispatched. In this case, the service returns immediately with a HTTP 200 OK response, and with no content.

    This service is then served via the Http protocol on TCP port 8080. Finally we wait for the server to stop serving.

    We can now query our web server:

    % curl -D - localhost:8080
    HTTP/1.1 200 OK

    Building an HTTP client is also simple. (Note that type annotations are added for illustration.)

    import com.twitter.finagle.{Http, Service}
    import com.twitter.finagle.http.{Request, Response}
    import com.twitter.util.{Future, Return, Throw}
    
    val client: Service[Request, Response] = Http.client.newService("localhost:8080")
    val f: Future[Response] = client(Request()).respond {
      case Return(rep) =>
        printf("Got HTTP response %s\n", rep)
      case Throw(exc) =>
        printf("Got error %s\n", exc)
    }

    Http.client.newService("localhost:8080") constructs a new com.twitter.finagle.Service instance connected to localhost TCP port 8080. We then issue a HTTP/1.1 GET request to URI "/". The service returns a com.twitter.util.Future representing the result of the operation. We listen to this future, printing an appropriate message when the response arrives.

    The Finagle homepage contains useful documentation and resources for using Finagle.

    Definition Classes
    twitter
  • package thriftmux
    Definition Classes
    finagle
  • package service
    Definition Classes
    thriftmux
  • ThriftMuxResponseClassifier

package service

Ordering
  1. Alphabetic
Visibility
  1. Public
  2. All

Value Members

  1. object ThriftMuxResponseClassifier

    ResponseClassifiers for use with finagle-thriftmux request/responses.

    ResponseClassifiers for use with finagle-thriftmux request/responses.

    Thrift (and ThriftMux) services are a bit unusual in that there is only a single com.twitter.finagle.Service from Array[Byte] to Array[Byte] for all the methods of an IDL's service.

    ThriftMux classifiers should be written in terms of the Scrooge generated request $Service.$Method.Args type and the method's response type. This is because there is support in Scrooge and ThriftMux.newService/newClient to deserialize the responses into the expected application types so that classifiers can be written in a normal way.

    Given an idl:

    exception NotFoundException { 1: string reason }
    exception RateLimitedException { 1: string reason }
    
    service SocialGraph {
      i32 follow(1: i64 follower, 2: i64 followee) throws (
        1: NotFoundException ex, 2: RateLimitedException ex
      )
    }
    

    One possible custom classifier would be:

    val classifier: ResponseClassifier = {
      case ReqRep(_, Throw(_: RateLimitedException)) => RetryableFailure
      case ReqRep(_, Throw(_: NotFoundException)) => NonRetryableFailure
      case ReqRep(_, Return(x: Int)) if x == 0 => NonRetryableFailure
      case ReqRep(SocialGraph.Follow.Args(a, b), _) if a <= 0 || b <= 0 => NonRetryableFailure
    }

    Often times, a good default classifier is ThriftMuxResponseClassifier.ThriftExceptionsAsFailures which treats any Thrift response that deserializes into an Exception as a non-retryable failure.

Ungrouped