Chapter 30. Configuring Java Message Service bridges

Procedure

1. Open the management console in a browser and navigate to Configuration Subsystems Messaging (ActiveMQ) JMS Bridge.
2. Click the Add (+) button and provide the required information when prompted.

3. Click Add when finished.

   Quality of service

   In JBoss EAP, quality-of-service is a configurable attribute that determines how messages are consumed and acknowledged. The valid values for quality-of-service and their descriptions are below. See the table in the appendix for a full list of Java Message Service bridge attributes.

   AT_MOST_ONCE

   Messages will reach the destination from the source at the most one time. The messages are consumed from the source and acknowledged before sending to the destination. Therefore, there is a possibility that messages could be lost if a failure occurs between their removal from the source and their arrival at the destination. This mode is the default value.

   This mode is available for both durable and non-durable messages.

   DUPLICATES_OK

   Messages are consumed from the source and then acknowledged after they have been successfully sent to the destination. Therefore, there is a possibility that messages could be sent again if a failure occurs after the initial message was sent but before it is acknowledged.

   This mode is available for both durable and non-durable messages.

   ONCE_AND_ONLY_ONCE

   Messages will reach the destination from the source once and only once. If both the source and the destination are on the same server instance, this can be achieved by sending and acknowledging the messages in the same local transaction. If the source and destination are on different servers, this is achieved by enlisting the sending and consuming sessions in Jakarta Transactions. The transaction is controlled by a Transaction Manager which will need to be set using the setTransactionManager() method on the bridge.

   This mode is only available for durable messages.

   Warning

   When shutting down a server that has a deployed Java Message Service bridge with the quality-of-service attribute set to ONCE_AND_ONLY_ONCE, be sure to shut the server down with the Java Message Service bridge first to avoid unexpected errors.

   It may possible to provide once and only once semantics by using the DUPLICATES_OK mode instead of ONCE_AND_ONLY_ONCE and then checking for duplicates at the destination and discarding them. See Configuring Duplicate Message Detection for more information. However, the cache would only be valid for a certain period of time. This approach therefore is not as watertight as using ONCE_AND_ONLY_ONCE, but it may be a good choice depending on your specific application needs.

   Timeouts and the Java Message Service bridge

   There is a possibility that the target or source server will not be available at some point in time. If this occurs, the bridge will try to reconnect a number of times equal to the value of max-retries. The wait between attempts is set by failure-retry-interval.

   Warning

   Because each Java Message Service bridge has its own max-retries parameter, you should use a connection factory that does not set the reconnect-attempts parameter, or sets it to 0. This will avoid a potential collision that may result in longer reconnection times. Also note that any connection factory referenced by a Java Message Service bridge with the quality-of-service set to ONCE_AND_ONLY_ONCE needs to have the factory-type set to XA_GENERIC, XA_TOPIC, or XA_QUEUE.