If a core group includes a cluster of application servers, and a messaging engine is configured for that cluster, any of the servers in that cluster can handle work items for the messaging engine. The default message provider in WebSphere Application Server is based on Service Integration Bus (SIB) technology, and is governed by the Default SIBus policy, which is a One of N policy. This policy ensures that only one of the application servers in the cluster is active at a time). You can modify the high availability group policy to specify that a specific cluster member handles the messaging work.
Before you begin
Before specifying a preferred server for messaging requests:It is possible for a single policy to govern several different high availability groups. Therefore, to modify the policy for cluster scoped control, you must create a new policy specific to the high availability group that controls the messaging engine cluster. See Creating a policy for a high availability group for more information on how to create this policy.
After you create the new policy and associate the policy with the high availability group for a given cluster, You can specify a preferred server for messaging requestws..
Why and when to perform this task
For high availability, you must configure a messaging engine to run in a cluster. However, you might want a specific cluster member to handle the messaging requests. Another member of the cluster should handle the messaging requests only if the preferred member fails.Steps for this task
Click Add to move core group servers into the list of preferred servers.
Select specific servers in the list and click Move up and Move down to adjust the order of the servers within the list. Make sure that the most preferred server is at the beginning of the list and the least preferred server is at the end of the list.
Result
All work items for the messaging engine on the associated cluster are routed to the new preferred server.Related tasks
Setting up a high availability environment