Technical data

Managing the Queue Manager and Queue Database
13.1 Understanding the Queue Manager
One or more queue manager processes control queuing for all processes on a
node or in an OpenVMS Cluster environment. Jobs can be submitted from one
node and executed on a queue running on another cluster node. User processes,
symbionts, and job controllers on each node communicate directly with queue
managers.
In addition, the job controller works with the queue manager to perform the
following queue management tasks:
• Create and monitor batch, symbiont, and queue manager processes
• Restart the queue manager process on reboot
• Handle failover of the queue manager in an OpenVMS Cluster environment
Queue Manager Failover
By default, in an OpenVMS Cluster environment, the queue manager tries to fail
over to another node if the node on which the queue manager is running leaves
the cluster.
You can specify the order in which OpenVMS Cluster nodes claim the queue
manager process; you can also limit the nodes that can run the queue manager.
For more information, see Section 13.6.
Multiple Queue Managers
To work around CPU, disk space, or memory limitations, you can use multiple
queue managers to distribute the batch and print work load among nodes as well
as to distribute the database files among disks.
For example, you might create separate queue managers for batch queues and
print queues. Run the batch queue manager on one node and the print queue
manager on a different node. You can also maintain queue and journal files on
separate disks.
For information about creating additional queue managers, including reasons and
restrictions for using multiple queue managers, see Section 13.8.
13.2 Understanding the Queue Database
The queue database contains files that store information used to keep the queuing
system operating, including information about jobs, queues, and the queue
manager. The queue database for the default queue manager, SYS$QUEUE_
MANAGER, is made up of the following files:
File Description
Master file,
QMAN$MASTER.DAT
Contains:
• The location of the queue and journal files
• Definitions of forms and characteristics
• A list of queue names
• A list of nodes allowed to run the queue manager
• A list of queue managers and a list of nodes allowed
to run the queue managers
Managing the Queue Manager and Queue Database 13–3