Where is wrong in my remote actor demo? - scala

Question

I'm trying to send messages to a remote actor, but failed.
My main code is:
RemoteActorDemo.scala
import akka.actor.{Actor, ActorSystem, Props}
object RemoteActorDemo extends App {
val system = ActorSystem("RemoteActorSystem")
val actor = system.actorOf(Props[RemoteActor], name = "RemoteActor")
actor ! "Remote Actor is alive"
}
class RemoteActor extends Actor {
override def receive: Receive = {
case msg =>
println("### RemoteActor received message: " + msg)
sender ! "Hello from RemoteActor"
}
}
With application.conf:
akka {
actor {
provider = "akka.remote.RemoteActorRefProvider"
}
remote {
enabled-transports = ["akka.remote.netty.tcp"]
netty.tcp {
hostname = "127.0.0.1"
port = 5150
}
}
}
And LocalActorDemo.scala:
import akka.actor.{Actor, ActorSystem, Props}
object LocalActorDemo extends App {
val system = ActorSystem("ActorDemo")
val localActor = system.actorOf(Props[LocalActor])
localActor ! "Start"
}
class LocalActor extends Actor {
val remote = context.actorSelection("akka.tcp://RemoteActorSystem#127.0.0.1:5150/user/RemoteActor")
override def receive: Receive = {
case "Start" =>
println("### LocalActor started")
remote ! "Hello from LocalActor"
case msg => println("*** LocalActor receives msg: " + msg)
}
}
The problem is the local actor can't connect the remote one. It prints in console:
### LocalActor started
[INFO] [10/05/2015 20:57:57.334] [ActorDemo-akka.actor.default-dispatcher-4] [akka://ActorDemo/deadLetters]
Message [java.lang.String] from Actor[akka://ActorDemo/user/$a#-11944341] to Actor[akka://ActorDemo/deadLetters]
was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration
settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
I'm new to akka, not sure where is wrong.
You can see the demo project here: https://github.com/freewind/remote-actors-demo, you can just clone and run it as "README" describes.

Answer 1

Add an application.conf in your local subproject with content like this:
akka {
actor {
provider = "akka.remote.RemoteActorRefProvider"
}
remote {
enabled-transports = ["akka.remote.netty.tcp"]
netty.tcp {
hostname = "127.0.0.1"
port = 0
}
}
}
As the official document says:
To enable remote capabilities in your Akka project you should, at a minimum, add the following changes to your application.conf file
This applied to the client side of a remoting system as well.