You can configure PrintKit queues on a VMScluster for automatic failover to a backup node in the event that their primary node becomes unavailable. You do this using the OpenVMS autostart queue mechanism, which is supported by PrintKit.
An ordinary print queue is located on a specified node within the cluster. In contrast, an autostart queue may be located on one of several nodes, and if the node currently in use becomes unavailable, the OpenVMS job control program will restart the queue on the next alternate node.
1.Your queue manager should already be configured for cluster-wide operation and failover. In particular, the master queue database file, QMAN$MASTER.DAT, must be on a disk shared by all nodes that access the database. By default, the database is in SYS$COMMON:[SYSEXE], but QMAN$MASTER may be defined as a logical name to specify another location.
Make sure PrintKit's configuration database file, PRINTKIT_CONFIG.DAT, is in the same directory as QMAN$MASTER.DAT. If the two are in different locations, stop any active PrintKit queues and move PRINTKIT_CONFIG.DAT:
$ KITCP
KITCP> STOP QUEUE/ALL
$ BACKUP SYS$MANAGER:PRINTKIT_CONFIG.DAT -
disk:[directory]/VERIFY/DELETE
(Specify the actual disk and directory for your configuration.)
2.Make sure the PrintKit License PAK is installed on each node to be used by your PrintKit autostart queues. (If you have a PrintKit Server License, see the note below concerning PrintKit Server License PAKs.)
3.Enable autostart on the nodes desired. This can be done with the following VMS command:
$ ENABLE AUTOSTART/QUEUE
This command should be placed in the startup file of each node involved (normally SYS$STARTUP: SYSTARTUP_VMS.COM). Be sure to enable autostart after starting your TCP/IP services, not before.
4.Create or modify your PrintKit queue to be an autostart queue, and specify a failover list. An example:
$ KITCP
KITCP> MODIFY QUEUE PRINTKIT -
_KITCP> /AUTOSTART_ON=(NODE1::TCPIP,NODE2::TCPIP)
5.Start the queue (The queue should start automatically after the next reboot):
$ START/QUEUE PRINTKIT
If you are using PrintKit with a server license (your LMF License PAK specifies availability, not activity, units), LMF will not allow automatic failover – the license remains associated with the failed system, and is not available for re-use until it has been manually unloaded and reloaded.
Contact us for a workaround.
The OpenVMS Guide to System Management provides a general discussion of autostart queues. VMScluster Systems for OpenVMS describes configuration of the queue manager for cluster-wide operation and failover.