EAR versus WAR deployment

MQ listeners operations depend on whether Pega Platform is deployed as an Enterprise application (EAR file) or a Web application (WAR file). See the Pega Community article Using MQ and JMS Services with Enterprise Application deployment.

When and how MQ listeners run

Three settings affect how MQ listener requestors run. They control whether the listeners can run, when the listeners start, and where the listeners can run:

1. Whether — Controlled by the Blocked field on the Properties tab of this form.
2. When — Controlled by the initServices/initMQ entry in the prconfig.xml file or dynamic system settings. (enabled by default)
3. Where — Controlled by the node list on the Properties tab of this form.

Controlling whether listeners start

The Blocked check box on the Properties tab determines whether the listener requestors defined by this MQ Listener data instance start. If this check box is cleared, these listeners start when Pega Platform starts (on eligible nodes). You can also stop and restart listeners from Admin Studio.

If the Blocked check box is selected, they do not start when a Pega Platform node starts and you cannot start them from Admin Studio until you clear the Blocked option and save the listener instance.

Controlling when listeners start

The prconfig.xml file or dynamic system settings control when MQ listeners start. To cause unblocked MQ listeners to start when Pega Platform starts, edit this file to add or update the initServices/initMQ setting:

<env name="initServices/initMQ" value="true"/>

If this entry is not present in the file, or the value is not set to "true","y", or "yes", you can start unblocked MQ listeners only from Admin Studio.

Controlling where listeners run

The options listed in the Start Option property on the on the Properties tab determine where the listener starts. The following options are available.

• Run on all nodes — The listener is run on all nodes for all servers in a cluster.
• Node based startup — The listener is started only on specified nodes.
• Host based startup — The listener is started on a specified number of nodes on specific servers within the cluster.

Listener restart after service rule changes

Any change to the Service Email rule on the Service, Request, or Response tab requires that you restart the listener from Admin Studio. If you do not restart the listener, the changes do not take effect.

MQ Listener dynamic system settings

You can use the following dynamic system settings to modify the behavior of MQ Listener processing on your system:

Remote logging

Use the remote logging feature to debug MQ listeners:

• On the Properties tab, identify a workstation that will receive logging output.
• Use Admin Studio to start the listener.