If you choose to create the queue manager separately, set up a dead letter queue (DLQ). The DLQ is referenced by WebSphere Message Broker when errors occur processing messages in message flows.
If a message in either a user-defined message flow or in the publish/subscribe model cannot be processed, it is routed to this DLQ as a last resort. If you would prefer the message to be backed out onto the input queue, effectively halting the message flow until the problem is resolved, disable the DLQ.
The mqsideleteusernameserver command does not delete this queue (unless the queue manager is deleted).
If you are using a WebSphere MQ queue manager that has been created independently of the mqsicreateusernameserver command, you can define clusters. This simplifies your configuration.
If the queue manager is created by this command, it is not started as a Windows service; it stops if you log off. To avoid this happening, either remain logged on, or change the start up status of the queue manager service. (If you lock your workstation, the WebSphere MQ queue manager does not stop).