wM MQ Adaptor Asynchronous Listener, when listening to an MQ Queue, will pickup inbound messages and pass it over to the Broker, which them send the messages (to the wM IS) for who has subscribed (via trigger) to the message.
How does these « listener » work when we have the Broker (and the wM IS) are in a Cluster environment?
As an example, we have 5 servers running the following:
» MQ Manager with its queues on server Z1
» broker A on server A1
» broker B on server B1 – both clustered together
» wM IS C on server C1
« wM IS D on server D1– both in clustered together
Where do we install the listener? on both wM IS boxes (C1 & D1) ?
Which broker will pickup the inbound message (out of the Z1 queue server) when the wM MQ Adaptor listener will start processing ?
Since both the brokers A and B are clustered and if the configuration of broker instances are active-passive then i assume only one broker should be running at one point of time. Also both the IS instances should have been configured to connect to the same broker.
Configuring MQ listeners in one IS or both the IS depends on whether you want to have failover and scalability in you solution or not and how you want to achieve the failover and scalability. If you want to have a failover for your MQ based integrations then do the following:
Install the MQ adapter in both the IS servers
Create MQ Connections, MQ Listeners, Listener Notifications and Triggers in both the IS servers. The connection pool name, listener name, listener notification, triggers and the configuration of all of these elements should be identical in both the IS servers. Alternatively you can create all this in one IS and then deploy them in the second IS.
If message ordering and duplication is permitted in your case then enable the MQ connections, MQ listeners, Listener Notifcations and Triggers in both IS servers. This way you can achieve load balancing as well automatic failover.
If message ordering and duplication is NOT permitted then enable the MQ connection, MQ listener, Listener Notification and Trigger in the first IS and leave them disabled in the second IS. In this case only one IS will process all the MQ messages maintaining the message (document) ordering and preventing message duplication. Whenever there is a failure in the first IS then enable the MQ connection, MQ listener, Listener Notification and Trigger in the second IS. In this case scalability cannot be achieved.
If you dont want to have a failover then just install the MQ adapter in one IS and configure MQ connection, MQ listener, Listener Notification and Trigger in one IS.
If your IS servers are pointing to two different Brokers then the IS server which hosts your MQ integration will use the Broker that is configured for that IS.