In the latest release of IBM MQ 9.4.0.0, there have been significant changes to the default behaviour of the AMQP (Advanced Message Queuing Protocol) service startup. This update affects how the AMQP service is initiated when creating and starting new queue managers.
What's Changed?
Prior to IBM MQ 9.4.0, the default setting for the CONTROL attribute that starts the AMQP service was set to QMGR. This meant that even if you didn't actively use the AMQP component, the service would start automatically upon queue manager startup. To avoid this automatic startup, users had to either refrain from installing the AMQP component or manually change the CONTROL attribute to MANUAL after queue manager startup.
However, starting from IBM MQ 9.4.0, newly created queue managers now default to having the CONTROL attribute of the SYSTEM.AMQP.SERVICE set to MANUAL, which was the default behaviour before IBM MQ 9.0.4. This change means that the AMQP service no longer automatically starts with the queue manager.
Migrated Queue Managers
For migrated queue managers that utilize AMQP, the AMQP service will still auto-start during the queue manager startup process. The system checks for existing AMQP channels and examines the AMQP error log for channel start messages to determine if AMQP is being used.
How to Enable Auto-Start
If you want the AMQP service to automatically start with the queue manager, you can change the CONTROL attribute of the service to QMGR and then restart the queue manager. Subsequent restarts of the queue manager will also start the AMQP service automatically.
Example you can use runmqsc command alter to change CONTROL attribute of the service to QMGR
runmqsc <QmgrName>
alter service(SYSTEM.AMQP.SERVICE) CONTROL(QMGR)
end
Summary
In summary, the default behaviour of the AMQP service startup has changed in IBM MQ 9.4.0 to provide more control over when the service initiates. This change aims to optimize resource usage and provide flexibility to users based on their specific AMQP utilization needs.
For more detailed instructions or inquiries, please refer to the official IBM MQ documentation.
Useful links:
IBM MQ 9.4 Documentation
Change to the start of the AMQP Service