WebLogic: The Definitive Guide

Controlling Message Delivery

WebLogic provides a number of features that can be used to control the different aspects of message delivery and handling. These features are critical in building a robust and scalable messaging system.

The timed message delivery feature lets you control exactly when messages are delivered. Using this mechanism, you can either configure a delay before the message is actually delivered, or set up a custom schedule for a destination that determines the permitted days and times during which the messages may be delivered. In this way, you can ensure that messages are delivered only when their consumers are ready to process them. The time-to-live attribute lets you adjust the maximum age of the outgoing messages — i.e., the maximum time period for which the messages will be retained by the system. After this time period, the messages will have expired and will no longer be tracked by the JMS server. The previous section showed how WebLogic can periodically reap expired messages from the JMS server.

WebLogic also provides enhanced support for redelivery by letting you limit the number of attempts at redelivery and configure a pause between redelivery attempts. WebLogic JMS makes two additional acknowledge modes available. The NO_ACKNOWLEDGE mode instructs the JMS server to not expect acknowledgment for the message. The MULTICAST_NO_ACKNOWLEDGE mode is similar, except that it enables the JMS client to use a more scalable multicast message distribution when ...