I am writing a java/scala akka proof of concept and currently I am fumbling with the actor concept in a cluster environment.
Specification
I have a specific situation where a system sends the same messages to multiple nodes. My job is to not drop any of those messages and pass only 1 message to a backend system. Like a unique filter with load balancing/fail-over capabilities.
Idea
I was thinking of using 2 "frontend" actors on 2 nodes and the system would send messages to a frontend router (lets say round-robin) which sends to the frontend actors that send to the backend.
The other fallback solution would be to use a only-leader-send-to-backend system where they all get the same message and only the leader passes it forward.
Problem
The problem I am facing (see code) is that I want the router to use existing frontend actors as routees on the cluster. This fails in the sample code because the router looks for the routees by routees-path (config setting) only locally, doesn't find any and dies.
I haven't had success with the config where the router deploys routees on the cluster nodes either. It would always deploy them locally.
I have sample code here http://ge.tt/2UHUqoQ/v/0?c. There are 2 entry points * TransformationSample.App2 - run two instances with commandline params 2551 and 2552 each (seed nodes) * TransformationSample.App1 - run one instance with no commandline params
The App1 is the one that tries to create a router and communicate with it but the router terminates because it can't find the frontend routers locally. I have the issue pinned to the akka.cluster.routing.ClusterRouteeProvider class createRoutees method line 178 https://github.com/akka/akka/blob/releasing-2.1.0-RC1/akka-cluster/src/main/scala/akka/cluster/routing/ClusterRouterConfig.scala.
In closing
I am probably doing something wrong here and please excuse my scala (this is the first project I am writing it with).
The reason why I am wishing for this router thingy to work is because the next step of the proof of concept would be to load balance the backend system with a similar setup where the frontend actors would communicate with a (separate) backend cluster router which sends work round-robin to backend actors.
Is this over-engineered? We have to have fail-over for the front part and load balancing on the back part.
