package twitter
Start with com.twitter.finagle.
Package Members
- 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.
Type Members
- class serverset extends IdPrefixingNamer
The serverset namer takes Paths of the form
The serverset namer takes Paths of the form
hosts/path...
and returns a dynamic represention of the resolution of the path into a tree of Names.
The namer synthesizes nodes for each endpoint in the serverset. Endpoint names are delimited by the ':' character and shard IDs are delimited by the '#' character. For example:
/$/com.twitter.serverset/sdzookeeper.local.twitter.com:2181/twitter/service/cuckoo/prod/read:http#0
is the endpoint
http
of shard 0 of serverset/twitter/service/cuckoo/prod/read
on the ensemblesdzookeeper.local.twitter.com:2181
.