Not able to lookup a custom dispatcher

Question

I am using Play 2.3.7 and I need to use Actors from inside the controller. The following code is working fine

implicit val system = ActorSystem()
implicit val dispatcher = system.dispatcher
val future = (IO(Http) ? Get(url).withHeaders(...).mapTo[HttpResponse]
val result = Await.results(future, Duration.Inf)

Now I make the following change to my conf/application.conf

play {
  akka {
    actor {
      default-dispatcher {
        type = Dispatcher
        executor = "thread-pool-executor"
        thread-pool-executor {
          fixed-pool-size = 128
        }
      }
      foo-dispatcher {
        type = Dispatcher
        executor = "thread-pool-executor"
        thread-pool-executor {
          fixed-pool-size = 128
        }
      }
    }
  }
}

And now, change my code to

implicit val system = ActorSystem()
implicit val dispatcher = system.dispatchers.lookup("foo-dispatcher")
val future = (IO(Http) ? Get(url).withHeaders(...).mapTo[HttpResponse]
val result = Await.results(future, Duration.Inf)

I get an exception with message [foo-dispatcher] not configured

Answer 1

Reference the full path:

implicit val dispatcher = system.dispatchers.lookup("play.akka.actor.foo-dispatcher")

If you want to use system.dispatchers.lookup("foo-dispatcher"), define foo-dispatcher outside of the play namespace:

play {
  akka {
    actor {
      default-dispatcher {
        type = Dispatcher
        executor = "thread-pool-executor"
        thread-pool-executor {
          fixed-pool-size = 128
        }
      }
    }
  }
}

foo-dispatcher {
  type = Dispatcher
  executor = "thread-pool-executor"
  thread-pool-executor {
    fixed-pool-size = 128
  }
}