How to Use Phoenix.PubSub for Inter-Node Messaging in Elixir Clusters

This article by Mạnh Vũ offers a guide on how to use Phoenix.PubSub as a message bus for Elixir clusters. The author explains the simplicity and effectiveness of this approach for small to medium systems. The article includes a step-by-step process to add necessary dependencies such as `phoenix_pubsub` and `libcluster` to an Elixir project, detailing configuration settings required in `config.exs`. The article also covers setting up PubSub in the application supervisor, subscribing to topics, broadcasting messages, and handling messages in GenServers. Illustrative code snippets and a sample case diagram are provided to aid understanding.