Attributes for queues

Use this information to learn about the different types of queue definitions and the attributes supported by each.

Local queue

This is a physical queue that stores messages. The queue exists on the local queue manager.

Applications connected to the local queue manager can place messages on and remove messages from queues of this type. The value of the QType queue attribute is QTLOC.

Shared queue

This is a physical queue that stores messages. The queue exists in a shared repository that is accessible to all of the queue managers that belong to the queue sharing group that owns the shared repository. Applications connected to any queue manager in the queue sharing group can place messages on and remove messages from queues of this type. Such queues are effectively the same as local queues. The value of the QType queue attribute is QTLOC.

• Shared queues are supported only on z/OS®.

Cluster queue

This is a physical queue that stores messages. The queue exists either on the local queue manager, or on one or more of the queue managers that belong to the same cluster as the local queue manager.

Applications connected to the local queue manager can place messages on queues of this type, regardless of the location of the queue. If an instance of the queue exists on the local queue manager, the queue behaves in the same way as a local queue, and applications connected to the local queue manager can remove messages from the queue. The value of the QType queue attribute is QTCLUS.

Alias queue

This is not a physical queue - it is an alternative name for a local queue. The name of the local queue to which the alias resolves is part of the definition of the alias queue.

Applications connected to the local queue manager can place messages on and remove messages from alias queues - the messages are placed on and removed from the local queue to which the alias resolves. The value of the QType queue attribute is QTALS.

Remote queue

This is not a physical queue - it is the local definition of a queue that exists on a remote queue manager. The local definition of the remote queue contains information that tells the local queue manager how to route messages to the remote queue manager.

Applications connected to the local queue manager can place messages on remote queues - the messages are placed on the local transmission queue used to route messages to the remote queue manager. Applications cannot remove messages from remote queues. The value of the QType queue attribute is QTREM.

A remote queue definition can also be used for:

• Reply-queue aliasing

  In this case the name of the definition is the name of a reply-to queue. For more information, see Reply-to queue alias definitions.

• Queue manager aliasing

  In this case the name of the definition is an alias for a queue manager, and not the name of a queue. For more information, see Queue manager alias definitions.

Model queue

This is not a physical queue - it is a set of queue attributes from which a local queue can be created.

Messages cannot be stored on queues of this type.

Some queue attributes apply to all types of queue; other queue attributes apply only to certain types of queue. The types of queue to which an attribute applies are indicated by the

symbol in Table 1 and subsequent tables. Table 1 summarizes the attributes that are specific to queues. The attributes are described in alphabetical order. Note: The names of the attributes shown in this section are the names used with the MQINQ and MQSET calls. When MQSC commands are used to define, alter, or display attributes, alternative short names are used; see Script (MQSC) Commands for details.