Java Message Service, 2nd Edition

Messaging Design Anti-Patterns

There are several messaging-related anti-patterns that manifest themselves in production environments. An anti-pattern is a practice that is repeated but produces negative results (unlike a pattern, which is a repeatable process that produces positive results). Three of the most common messaging anti-patterns are the single-purpose queue, message priority overuse, and message header misuse. This section will cover the details of each of these anti-patterns and describe ways to avoid them.

Single-Purpose Queue

A common messaging anti-pattern is designing a system with only a single purpose queue. Typically this problem manifests itself when a single queue handles different types of messages (e.g., book orders, order status requests, and order cancellations), but problems can also occur when a single purpose queue is used for the same type of message (e.g., book orders). We will start with the first scenario since it is most common, and then move onto the second scenario, which is a little more subtle.

Systems that use a single purpose queue often have a single message listener class that acts as a router. The router listener receives the next message on the queue, determines the message type, and redirects processing to some other class to process that message. This design scenario is illustrated in Figure 11-3.

The routing rules used by the listener router can be based on the JMS message type (e.g., TextMessage, StreamMessage), a custom message property, ...