Configure a queue manager cluster
Clusters provide a mechanism for interconnecting queue managers in a way that simplifies both the initial configuration and the ongoing management. We can define cluster components, and create and manage clusters.
Before you begin
For an introduction to clustering concepts, see Clusters .
When
you are designing your queue manager cluster we have to make some
decisions. See Example clusters and Designing
clusters .
Defining components of a cluster
Clusters are composed of queue managers, cluster channels, and cluster queues. We can define cluster queues, and modify some aspects of default cluster objects. We can get configuration and status information about auto-defined channels, and about the relationship between individual cluster-sender channels and transmission queues.
Set up a new cluster
Follow these instructions to set up the example cluster. Separate instructions describe setting up the cluster on TCP/IP, LU 6.2, and with a single transmission queue or multiple transmission queues. Test the cluster works by sending a message from one queue manager to the other.
Add a queue manager to a cluster
Follow these instructions to add a queue manager to the cluster you created. Messages to cluster queues and topics are transferred using the single cluster transmission queue SYSTEM.CLUSTER.TRANSMIT.QUEUE.
Add a queue manager that hosts a queue
Add another queue manager to the cluster, to host another INVENTQ queue. Requests are sent alternately to the queues on each queue manager. No changes need to be made to the existing INVENTQ host.
Add a queue sharing group to existing clusters
Add a queue sharing group on z/OSĀ® to existing clusters.
Moving a full repository to another queue manager
Move a full repository from one queue manager to another, building up the new repository from information held at the second repository.
Establishing communication in a cluster
A channel initiator is needed to start a communication channel when there is a message to deliver. A channel listener waits to start the other end of a channel to receive the message.
Converting an existing network into a cluster
Convert an existed distributed queuing network to a cluster and add an additional queue manager to increase capacity.
Creating two-overlapping clusters with a gateway queue manager
Follow the instructions in the task to construct overlapping clusters with a gateway queue manager. Use the clusters as a starting point for the following examples of isolating messages to one application from messages to other applications in a cluster.
Removing a cluster queue from a queue manager
Disable the INVENTQ queue at Toronto. Send all the inventory messages to New York, and delete the INVENTQ queue at Toronto when it is empty.
Removing a queue manager from a cluster
Remove a queue manager from a cluster, in scenarios where the queue manager can communicate normally with at least one full repository in the cluster.
Restoring a queue manager to its pre-cluster state
When a queue manager is removed from a cluster, it retains knowledge of the remaining cluster members. This knowledge eventually expires and is deleted automatically. However, if you prefer to delete it immediately, we can use the steps in this topic.
Maintaining a queue manager
Suspend and resume a queue manager from a cluster to perform maintenance.
Maintaining the cluster transmission queue
Make every effort to keep cluster transmission queues available. They are essential to the performance of clusters. On z/OS, set the INDXTYPE of a cluster transmission queue to CORRELID.
Refreshing a cluster queue manager
We can remove auto-defined channels and auto-defined cluster objects from the local repository using the REFRESH CLUSTER command. No messages are lost.
Recovering a cluster queue manager
Bring the cluster information about a queue manager up to date using the REFRESH CLUSTER runmqsc command. Follow this procedure after recovering a queue manager from a point-in-time backup.
Configure cluster channels for availability
Follow good configuration practices to keep cluster channels running smoothly if there are intermittent network stoppages.
Routing messages to and from clusters
Use queue aliases, queue manager aliases, and remote queue definitions to connect clusters to external queue managers and other clusters.
Use clusters for workload management
By defining multiple instances of a queue on different queue managers in a cluster we can spread the work of servicing the queue over multiple servers. There are several factors that can prevent messages being requeued to a different queue manager in the event of failure.
Parent topic: Configure distributed queuing
Related tasks
Related information