The high availability manager uses an ordered list of preferred
core group servers when it selects servers to host the coordinators.
If the default list is inappropriate, you can change the list such
that other servers are selected as coordinators.
Before you begin
Use the following guidelines to determine the appropriate
ordered list of preferred coordinators:
- Make sure that you are familiar with the content of the Core group coordinator topic.
- Select a set of servers that infrequently start and stop, are
stable, and that are located on capable systems with large amounts
of system memory and a fast processor.
Best practice: Even though
it is possible to use a deployment manager as a core group coordinator,
it is recommended that you use an application server that is not a
deployment manager.
bprac
About this task
You might want to change the ordered list of preferred core
group servers if:
- The system where the default coordinator is located has insufficient
resources or capacity to serve as a coordinator.
- A server that normally gets selected as the coordinator starts
and stops frequently.
To change the ordered list of preferred core group servers:
Procedure
- In the administrative console, click Servers > Core
groups > Core group settings and select an existing core group.
- Click Preferred coordinator servers and then add
or delete the appropriate application servers from the list of preferred
coordinator servers. Use Add and Remove to
move servers into and out of the list of core group servers on which
the coordinator service can run. Use Move up and Move down to
adjust the order of the servers within this list. Make sure that the
most preferred server is at the beginning of the list and the least
preferred server is at the end.
- Click OK, and then click Save to
save your changes.
- Select Synchronize changes with
nodes, and then click Save again.
Results
Your changes take effect immediately after synchronization
completes. The members of the core group pick up these changes dynamically.