Do not change any of the default policies that are shipped with the WebSphere Application Server product. If you need to use different polices, create new policies and specify a match criterion that matches multiple attributes contained in the name of the high availability group. A policy with a greater number of match criterion matches overrides the IBM provided default policies. The IBM provided policies are still available for your use if you encounter a problem with the policies you create.
Before changing the policy type for a high availability group, make sure you fully understand how the application server processes that are contained in that high availability group are configured and how they will be affected by the policy change. You must also verify that the component that uses that particular high availability group supports the new policy type. For example,
if the high availability group for the service integration bus is using a one of N policy, because it only wants one server to be active at any given point in time, and you change the policy associated with that group to All Active, the service integration bus high availability support no longer functions properly and data corruption might occur.
Adhere to the following requirements for matching a high availability group to a policy:
A single high availability group cannot match to more than one policy.
If the same match criteria is used for multiple policies, the high availability groups with names that match this criteria do not activate when the server is started and an error message, indicating that multiple policies match this group, is logged.
The same policy can be used for multiple high availability groups.
A hierarchy is used when matching a high availability group to a policy.
If multiple properties are used for the match criteria, the policy that has the most matches with the high availability group name is the policy that is used.
Example: If you have two policies, Policy A and Policy B, and
The match criteria for policy A is type=WAS_TRANSACTIONS.
The match criteria for policy B is both type=WAS_TRANSACTIONS and IBM_hc=TestCluster.
When the transaction manager high availability group is created, it is automatically associated with Policy B because it has the closet match to the group name, which is GN_PS=carbideCell\carbide\ServerA IBM_hc=TestCluster type=WAS_TRANSACTIONS
To change the policy for a high availability group:
Determine if there are any policy restrictions for this high availability group. Core group policies includes information about any policy restrictions for the IBM provided high availability groups.
Use the Core Group Runtime panel in the administrative console
to see a list of high availability groups exist for this core group and determine which ones need a new policy. While looking at this panel, you should note the group name properties for all of the groups you are changing.
Update the match criteria for each new policy so that it matches the original match criteria and at least one other attribute from the name of the high availability group with which you want to associate the new policy.
Two policies can not have exactly the same match criteria because only one policy can be associated with a given high availability group.
Click Save , select Synchronize changes with Nodes and then click Save again to save your changes.