Multiple queue manager versions in a queue-sharing group

A queue-sharing group can have V5.3, V5.3.1 and V6 queue managers active and accessing shared queues and other shared objects.

We recommend that you only have a mixed version queue-sharing group for the time it takes to migrate all queue managers to V6. Whilst the queue-sharing group contains mixed version queue managers, WebSphere MQ for z/OS V6 allows prototyping with new V6 facilities on a V6 queue manager, and tolerates operation at the V5.3 level or above.

 

Function restrictions in a mixed queue-sharing group

We cannot alter a CF structure object from CFLEVEL(3) to CFLEVEL(4) until all queue managers in the queue-sharing group have been started at V6 level.

We cannot delete a CF structure object until all queue managers in the queue-sharing group have been started at V6 level.

Queue managers below V6.0 cannot connect to the Coupling Facility structure identified by the CFLEVEL(4) CF structure object, which means they can neither access the queues defined on it, nor messages stored on the queue.

Since CFLEVEL(4) CF structures, and queues defined on them, are not available to queue managers below V6.0, there are some restrictions on how some queues are used. These are outlined in Table 11.

Table 11. Restrictions on queues when using mixed queue-sharing groups

Type of queue	Restriction
SYSTEM.QSG.TRANSMIT.QUEUE	For best results, this queue should be on a structure accessible to all members of the queue-sharing group. However, this means it cannot be used for transporting persistent messages within the queue-sharing group.
SYSTEM.QSG.CHANNEL.SYNCQ	This queue must be accessible to all channel initiators in the queue-sharing group. Therefore, if you are running a channel initiator on an WebSphere MQ for z/OS queue manager below V6.0, the queue must not be defined on a CF structure at CFLEVEL(4).
Shared transmission queues	These queues must be accessible to all channel initiators in the queue-sharing group. Therefore, if you are running a channel initiator on an WebSphere MQ for z/OS queue manager below V6.0, the queue must not be defined on a CF structure at CFLEVEL(4).

We can define and alter objects with QSGDISP(GROUP) from a V6 queue manager. Those objects and their resulting copy objects are accessible on all the queue managers, but on older version queue managers the new V6 attributes and values are not available.

On a V5.3 or 5.3.1 queue manager, MQSC commands using new V6 keywords and attribute values (but not new commands) can be entered for routing to a V6 queue manager using CMDSCOPE. Such commands, on whatever version queue manager, routed to a V5.3 or 5.3.1 queue manager using CMDSCOPE will fail.

The operations and control panels work as detailed in Operations and control panels.

PCF commands can be entered only on a V6 queue manager. If they use MQCACF_COMMAND_SCOPE they will fail on any queue manager they are routed to that is not at V6.