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 that is included in the product 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:
- You should review the following topics:
- You must determine:
- The name of the core group that includes the server that you want
to handle messaging requests.
- The name of the high availability group for the messaging function.
- The name of the policy that is associated with this high availability
group
- You must create a new policy specific to the high availability
group that controls the messaging engine cluster, if one does not
already exist.
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..
About 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.
Procedure
- In the administrative console, click core_group_name.
- Click the Runtime tab to determine both the name
of the high availability group, and the name of the policy that is
currently controlling the group. See Viewing high availability group information for more information on how
to perform this step. You must have at least one of the group members
running.
- In the administrative console, click core_group_name > Policies.
- Click the name of the policy that you want to modify.
- Under Additional Properties, select Preferred servers and select the preferred servers for this policy.
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.
- After you complete the preferred servers list, click OK.
- Click OK and then click Review.
- Select Synchronize changes with nodes, and then
click Save.
Results
All work items for the messaging engine on the associated
cluster are routed to the new preferred server.