Understanding Distributed Elixir and Erlang

Razvan Draghici's guide dives into the process of interconnecting Elixir nodes within a distributed system. Starting with the basics of node clustering by identifying nodes and using the 'ping' mechanism, Razvan unravels the complexities of operation and the various components that sustain such a system. The guide touches upon the arguments against the need for distribution of Elixir nodes, citing alternatives like Postgres and Redis for stateless applications, but also acknowledges use cases that necessitate node distribution, such as in scenarios found in Phoenix's LongPoll support or in constructing large-scale chat applications like Whatsapp. Razvan offers a walkthrough on setting up distributed systems from scratch, delving into manual starts, the role of the Erlang Port Mapper Daemon (EPMD), the connection of nodes, and the relevant processes responsible for managing the connected mesh of nodes including the 'net_kernel', 'epmd', and 'global_name_server'. The guide goes further to give practical demonstrations of message passing between nodes, constructing a simple distributed key-value store, and leveraging Phoenix.PubSub for broadcasting across a cluster. In essence, the guide aims to equip readers with the foundational knowledge and tools required for efficient management, fine-tuning, and debugging of distributed Elixir systems.