Message consumers

Message consumers

Message consumers can be classified as durable and non-durable subscribers and synchronous and asynchronous message consumers.

Durable subscribers
A durable subscriber is a message consumer that receives all messages published on a topic, including messages published while the subscriber is inactive.
Non-durable subscribers
A non-durable subscriber is a message consumer that only receives messages that are published while the subscriber is active. Messages delivered while the subscriber is inactive are lost.
Synchronous message consumers
The synchronous message consumer receives the messages from a queue synchronously.
Asynchronous message consumers
The asynchronous message consumer receives message from a queue asynchronously. The message listener registered by the application is invoked whenever a new message is available on the queue.
Poison messages in XMS
A poison message is one which cannot be processed by a receiving MDB application. If a poison message is encountered, the XMS MessageConsumer object can requeue it according to two queue properties, BOQUEUE, and BOTHRESH.
Parent topic: Writing XMS applications