MQ Cluster cover by Murali Krishna Nookella Murali Krishna Nookella covers MQ Cluster for the beginners in MQ Murali Krishna Nookella case by concept covers Message Queue

1. Queue Manager Clustering
Murali Krishna Nookella

7. Businesses are increasingly becoming aware of the advantages of
establishing an intranet or of connecting processors to a LAN. For
example, you might connect some AIX processors in the form of an SP2.
Processors that are linked in these ways benefit from support from
each other and have access to a far wider range of programs and data.
In the same way, WebSphere MQ queue managers can be connected to
form a cluster. This facility is available to queue managers on all
operating systems.
You can connect the queue managers by using any of the
communications protocols that are available on your operating system.
That is, TCP or LU6.2 on any operating system, NetBIOS, or SPX on
Windows.
Connections on more than one protocol can exist within a cluster. If you
try to make a connection to a queue manager by using a protocol that it
does not support, the channel does not become active.

22. One of the first decisions that must be made when setting up a cluster, is to
determine the queue managers that are to have a full repository. All other queue
managers must have a predefined CLUSSDR channel to one of the full repository
queue managers in the cluster.
You might call QM1 the primary repository, and QM4 the secondary, but this
relationship is true only from the point of view of QM2. Both full repository QMGRs
have equal rights and functions, as to the cluster.
The full and partial repositories store queue manager information like the creation
of a new queue for 30 days.
To prevent this data from expiring, the queue manager resends information about
themselves after 27 days. When data expires, it is not immediately removed; instead
it has a grace period of 60 days. If during the grace period, no changes occur then
the data is removed. This grace period provides a queue manager that was
temporarily out of service at the expiry date the right to rejoin if it does not stay
disconnected from the cluster for 90 days. Then, that queue manager no longer is
part of the cluster.

55. You do not need to alter any of your applications if you are going
to set up a simple WebSphere MQ cluster. The applications name
the target queue on the MQOPEN call as typical and are not
concerned about the location of the queue manager.
However, if you set up a cluster in which there are multiple
definitions for the same queue , you must review your applications
and modify them as necessary.
Additional information — Bind on group is a new feature added in
WebSphere MQ V7.1.
Addition of this feature includes two new message flags within the
message descriptor of messages:
• Last message in group: MQMF_LAST_MSG_IN_GROUP
• All other messages in group: MQMF_MSG_IN_GROUP