Working in Active/Active mode

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 you can, if you want, in Active/Passive Mode). If you plan to use both machines to run workload, provide each with sufficient capacity (processor, memory, secondary storage) to run the entire cluster workload at a satisfactory level of performance.

Note:
If you are using MSCS together with Microsoft(R) Transaction Server (COM+), you cannot use Active/Active mode. This is because, to use WebSphere MQ with MSCS and COM+: