🔗 Concurrent reads, serialized writes with GenServer and Registry

GenServer is often a beginner's first encounter with Elixir, but common pitfalls can arise, especially concerning data access patterns. This article highlights an issue when using GenServer.call for reading data as it serializes requests, blocking concurrent access and affecting performance, such as the refresh timer for data.

The solution involves utilizing Registry, which allows registering processes and storing data without the complexities of managing ETS lifecycle. By implementing a via tuple, the GenServer can store its state in Registry, enabling concurrent read access. The article provides a practical example with the FXRates module demonstrating how to effectively use Registry to facilitate concurrent reads while still serializing writes. This approach not only optimizes access patterns but simplifies code management as well.