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.
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.