Using Distributed Publish-Subscribe in the cluster
Akka clustering provides a fault-tolerant decentralized service to deploy actors. However, you need to know in advance in which node your actors are living to be able to interact with them. One module that can help us achieve this is Distributed Publish-Subscribe. This module brings the concept of a standard pub-sub pattern within our cluster.
This pattern provides a mediator actor that keeps an eventually consistent registry of actors across the cluster. This allows any actor on any node to send a message to a registered actor on any other node. Moreover, you can subscribe an actor to a topic. Once an actor publishes to that topic, all the subscribers get a copy of the message:
Getting ready
For this recipe, we will set up a cluster of nodes running on the same machine. For this, we will use two different ports specified in two different application.conf
files. We will run an application that will have a notification publisher and notification...