Goal

To distribute message processing across multiple consumers, allowing multiple messages to be processed in parallel (Figure C-1).

Figure C-1. Competing consumers

Participants

Interactions

One or more applications send messages to a queue. Multiple consumers access the queue, each reading different messages and processing them. Each message is read from the queue by one and only one consumer.

Notes

The Competing Consumers pattern is best implemented using JMS, as Internet mail providers generally do not support multiple readers on a single mailbox terribly well.