Akka clustering - one Manager Actor per node

Question

I’m working on an application that often queries a very large number of actors and hence sends / receives a very large number of messages. When the application is ran on a single machine this is not an issue because the messages are sent within the boundaries of a single JVM which is quite fast. However, when I run the application on multiple nodes (using akka-cluster) each node hosts part of these actors and the messages go over the network which becomes extremely slow.

One solution that I came up with is to have a ManagerActor on each node where the application is ran. This will greatly minimize the number of messages exchanged (i.e. instead of sending thousands of messages to each of the actors, if we run the application on 3 nodes we send 3 messages - one for each ManagerActor which then sends messages within the current JVM to the other (thousands of) actors which is very fast). However, I’m fairly new to Akka and I’m not quite sure that such a solution makes sense. Do you see any drawbacks of it? Any other options which are better / more native to Akka?

Answer 1

You could use Akka's Distributed Publish-Subscribe to achieve that. That way you simply start a manager actor on each node the usual way, have them subscribe to a topic, and then publish messages to them using that topic topic. There is a simple example of this in the docs linked above.