Hints and tips on using MSCS

This section contains some general information to help we use IBM MQ support for MSCS effectively.

How long does it take to fail a queue manager over from one machine to the other? This depends heavily on the amount of workload on the queue manager and on the mix of traffic, for example, how much of it is persistent, within sync point, and how much committed before the failure. IBM tests have given failover and failback times of about a minute. This was on a very lightly loaded queue manager and actual times will vary considerably depending on load.

Verify that MSCS is working
Follow these steps to ensure that we have a running MSCS cluster.
Manual startup and MSCS
For a queue manager managed by MSCS, we must set the startup attribute to manual. This ensures that the IBM MQ MSCS support can restart the MQSeries Service without immediately starting the queue manager.
MSCS and queue managers
Considerations concerning queue managers when using MSCS.
Always use MSCS to manage clusters
Do not try to perform start and stop operations directly on any queue manager under the control of MSCS, using either the control commands or the IBM MQ Explorer. Instead, use MSCS Cluster Administrator to bring the queue manager online or take it offline.
Work in Active/Active mode in MSCS
Both computers in the MSCS cluster can run queue managers in Active/Active mode. You do not need to have a completely idle machine acting as standby (but we can, if we want, in Active/Passive Mode).
PostOnlineCommand and PreOfflineCommand in MSCS
Use these commands to integrate IBM MQ MSCS support with other systems. We can use them to issue IBM MQ commands, wih some restrictions.
Use preferred nodes in MSCS
It can be useful when using Active/Active mode in MSCS to configure a preferred node for each queue manager. However, in general it is better not to set a preferred node but to rely on a manual failback.
COM+ errors when you install on MSCS
When you install IBM MQ on a newly-installed MSCS cluster, you might find an error with Source COM+ and Event ID 4691 reported in the Application Event log.

Parent topic: Supporting the Microsoft Cluster Service (MSCS)