play-ws-loadbalancer

Client side load balancer for Play 2 WS module based on Netflix' Ribbon.

Requirements

This module requires the Play framework version 2.4.x and works with Scala 2.11 and 2.10.

Usage

Add the WS and the load balancer module to your project's dependencies in build.sbt.

libraryDependencies ++= Seq(
  ws,
  "io.derjan" %% "play-ws-loadbalancer" % "0.1.0"
)

Create a load balancer object with a Ribbon load balancer, that fits your needs.

import scala.collection.JavaConverters._

val servers = Seq(new Server("localhost", 8080), new Server("localhost", 8081))
val builder = LoadBalancerBuilder.newBuilder[Server]()
val loadBalancer = new WSLoadBalancer(builder.buildFixedServerListLoadBalancer(servers.asJava))

The above example will use a Ribbon load balancer with a fixed list of servers. You can than inject the load balancer into your controller and wrap WS calls with it to get an endpoint from the server list.

class Application(ws: WSClient, loadBalancer: WSLoadBalancer) extends Controller {
  def index = Action.async {
    val response = loadBalancer withEndpoint { endpoint =>
      ws.url(s"$endpoint/my-path").get()
    }

    response map { result =>
      Ok(views.html.index(result))
    }
  }
}