MaxHandles (MQLONG)
This
is the maximum number of open handles that any one task can use concurrently.
Each successful MQOPEN call for a single queue (or for an object
that is not a queue) uses one handle. That handle becomes available for reuse
when the object is closed. However, when a distribution list is opened, each
queue in the distribution list is allocated a separate handle, and so that MQOPEN call
uses as many handles as there are queues in the distribution list. This must
be taken into account when deciding on a suitable value for MaxHandles
.
The MQPUT1 call performs an MQOPEN call as part of its processing; as a result, MQPUT1 uses as many handles as MQOPEN would, but the handles are used only for the duration of the MQPUT1 call itself.
On z/OS®, task means a CICS® task, an MVS™ task, or an IMS dependent region.
- On z/OS, the default value is 100.
- In all other environments, the default value is 256.
To determine the value of this attribute, use the MQIA_MAX_HANDLES selector with the MQINQ call.