IBM BJ0NJML Integration Guide - Page 179

Sequential Queues 3 Configure your external system and enterprise services to use the queues. 4 To enable message processing, you must configure the consumers value of the message queue. The system processes the messages after they are written to the queue. Sequential Queues The sequential queue is a JMS queue with a system cron task as a consumer. Messages in sequential queues are processed on a strict first-in-first-out basis, ensuring that messages are processed in the order that they are generated and received. When a message results in an error, the system generates an error file and does not process subsequent messages in the queue until the error is cleared. You can configure two system sequential queues for inbound and outbound message processing. A predefined cron task, JMSQSEQCONSUMER, polls the queues. There are two instances of the task, one that polls the inbound queue and one that polls the outbound queue. The following table describes the cron task parameters that you can configure. Parameter MESSAGEPROCESSOR QUEUENAME SELECTOR TARGETENABLED Description Java class that processes the messages from the queue. The system provides this class. Queue JNDI name, when the queue is created on the application server. The WHERE clause for configuring an instance of the cron task to process a subset of messages in the queue. This parameter is optional. The Boolean flag that controls whether the cron task runs in a specific application server. The default is 0 (false). This parameter applies only when the system is running a multi-application server environment. Continuous Queue The continuous queue is a JMS queue with a message-driven bean (MDB) as a consumer. By default, this queue is configured for enterprise services only. The queue does not process messages in first-in-first-out sequence, as the sequential inbound queue does. Messages are processed in a multi-threaded mode, which produces better system performance. JMS Queue Configuration 165