The Java Message Service (JMS) is a Java API that provides a common programming model for asynchronously sending events and data across enterprise messaging systems. JMS supports two models, publish-and-subscribe for one-to-many message delivery and point-to-point for one-to-one message delivery. Apama's correlator-integrated JMS messaging implements both these models.

When configured to use correlator-integrated JMS messaging, Apama applications map downstream (incoming) JMS messages to Apama events and map upstream (outgoing) Apama events to JMS messages.

Apama's correlator-integrated JMS messaging implements three levels of reliability, leveraging the more basic reliability mechanisms provided by JMS itself, and making them simpler to use. When the reliability level is set to EXACTLY_ONCE or AT_LEAST_ONCE, delivery is guaranteed because messages are logged by the broker in persistent storage until they are received and acknowledged. When the reliability level is set to BEST_EFFORT, message delivery is not guaranteed. For applications that do not require guaranteed message delivery, the BEST_EFFORT mode provides greater performance.

You can specify the JMS configuration in Apama Studio, either in the JMS Correlator-Integrated adapter editor or by editing sections of the XML and .properties configuration files directly. Note, however that the mapping configuration should always be edited using the Apama Studio adapter editor in this release.