Why and when to perform this task
Important:
- 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: