🔗 Building distributed systems with Elixir — 02: Correlated request–reply

What happens when multiple requests are sent from the same Elixir process? This article explains how to correlate request and reply messages in Elixir using unique request identifiers. By incorporating the use of make_ref/0 to generate distinct reference IDs for requests, the communication protocol allows a server to differentiate between responses for multiple requests from a single client process. The author illustrates this concept through a lightweight implementation of a client-server model using Elixir’s process primitives, avoiding higher-level abstractions like GenServer. The example provides clarity on the distinction between process identities and request identities, showcasing the vital role of correlating responses in asynchronous messaging. This foundational understanding prepares readers for further exploration of process monitoring in Elixir's distributed systems.