If you have not already done so, prepare the broker distribution before running the example.
To run the example, simply type mvn verify from this directory, or mvn -PnoServer verify if you want to start and create the broker manually.
This example demonstrates how ActiveMQ Artemis can be configured to provide a delayed redelivery in the case where a message needs to be redelivered.
Delaying redelivery can often be useful in the case that clients regularly fail or roll-back. Without a delayed redelivery, the system can get into a “thrashing” state, with delivery being attempted, the client rolling back, and delivery being re-attempted ad infinitum in quick succession, using up valuable CPU and network resources.
Re-delivery occurs when the session is closed with unacknowledged messages. The unacknowledged messages will be redelivered.
By providing a redelivery delay, it can be specified that a delay of, say, 10 seconds is implemented between rollback and redelivery. The specific delay is configurable on both a global and per destination level, by using wild-card matching on the address settings.
Redelivery delay is specified in the configuration file broker.xml:
In this example we set the redelivery delay to 5 seconds for the specific example queue. We could set redelivery delay on multiple queues by specifying a wild-card in the match, e.g. match="jms.#" would apply the settings to all JMS queues and topics.
We then consume a message in a transacted session, and rollback, and note that the message is not redelivered until after 5 seconds.
<address-setting match="exampleQueue"> <redelivery-delay>5000</redelivery-delay> </address-setting>