Usage (MQLONG)

This indicates what the queue is used for.

MQUS_NORMAL

This is a queue that applications use when putting and getting messages; the queue is not a transmission queue.

MQUS_TRANSMISSION

This is a queue used to hold messages destined for remote queue managers. When an application sends a message to a remote queue, the local queue manager stores the message temporarily on the appropriate transmission queue in a special format. A message channel agent then reads the message from the transmission queue, and transports the message to the remote queue manager. For more information about transmission queues, see Defining a transmission queue.

Only privileged applications can open a transmission queue for MQOO_OUTPUT to put messages on it directly. Usually, only utility applications do this. Ensure that the message data format is correct (see MQXQH - Transmission-queue header ) or errors might occur during the transmission process. Context is not passed or set unless one of the MQPMO_*_CONTEXT context options is specified.

To determine the value of this attribute, use the MQIA_USAGE selector with the MQINQ call.