MQSeries Question:

Cluster is said to be group of queue manager's logically
connected together to balance the load on the remote machine
(i.e if it is remote queue managers which processes your
message). And there are two types of grouping on the queue
managers.
1) Full repository
2) Partial repository.

The full repository queue manager knows all other queue
managers in the cluster and whenever a message comes to it,
and if that is unable to process the message, it will find
a queue in other queue manager in the cluster and ask it to
process the message.