Optimizing Message Publishing in Elixir with RabbitMQ

The post explores the challenges of achieving reliable message delivery in a pub-sub architecture using RabbitMQ. It highlights key practices like enabling publisher confirms, message persistence, durable queues, and consumer acking. The author contrasts synchronous handling of publisher confirmations, which can create bottlenecks, with an asynchronous approach using AMQP.Confirm.register_handler. The article details an implementation in a GenServer that allows efficient tracking of message acknowledgments (acks) and negative acknowledgments (nacks) using ETS (Erlang Term Storage) for mapping sequence numbers to processes. The solution allows for non-blocking message publishing, improving overall throughput and reliability.