Packages

•  package root

  Definition Classes

  root

•  package com

  Definition Classes

  root

•  package twitter

  Start with com.twitter.finagle.

  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 loadbalancer

  This package implements client side load balancing algorithms.

  This package implements client side load balancing algorithms.

  As an end-user, see the Balancers API to create instances which can be used to configure a Finagle client with various load balancing strategies.

  As an implementor, each algorithm gets its own subdirectory and is exposed via the Balancers object. Several convenient traits are provided which factor out common behavior and can be mixed in (i.e. Balancer, DistributorT, NodeT, and Updating).

  Definition Classes

  finagle

•  object LoadBalancerFactory

  Exposes a Stack.Module which composes load balancing into the respective Stack.

  Exposes a Stack.Module which composes load balancing into the respective Stack. This is mixed in by default into Finagle's com.twitter.finagle.client.StackClient. The only necessary configuration is a LoadBalancerFactory.Dest which represents a changing collection of addresses that is load balanced over.

  Definition Classes

  loadbalancer

• AddressFormatter
• AddressOrdering
• Dest
• EnableProbation
• ErrorLabel
• HostStats
• Param
• ReplicateAddresses

com.twitter.finagle.loadbalancer.LoadBalancerFactory

HostStats

Companion object HostStats