Queue names

 

The name of a queue has two parts:

• The name of a queue manager

• The local name of the queue as it is known to that queue manager

Each part of the queue name is 48 characters long.

To refer to a local queue, we can omit the name of the queue manager (by replacing it with blank characters or using a leading null character). However, all queue names returned to a program by WebSphere MQ contain the name of the queue manager.

A shared queue, accessible to any queue manager in its queue-sharing group, cannot have the same name as any non-shared local queue in the same queue-sharing group. This restriction avoids the possibility of an application mistakenly opening a shared queue when it intended to open a local queue, or vice versa. Shared queues and queue-sharing groups are only available on WebSphere MQ for z/OS.

To refer to a remote queue, a program must include the name of the queue manager in the full queue name, or there must be a local definition of the remote queue.

When an application uses a queue name, that name can be either the name of a local queue (or an alias to one) or the name of a local definition of a remote queue, but the application does not need to know which, unless it needs to get a message from the queue (when the queue must be local). When the application opens the queue object, the MQOPEN call performs a name resolution function to determine on which queue to perform subsequent operations. The significance of this is that the application has no built-in dependency on particular queues being defined at particular locations in a network of queue managers. Therefore, if a system administrator relocates queues in the network, and changes their definitions, the applications that use those queues do not need to be changed.

 

Parent topic:

Rules for naming WebSphere MQ objects

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