Set up a high availability environment
The WAS ND v9 high availability framework eliminates single points of failure and provides peer to peer failover for applications and processes. This infrastructure is managed by a high availability manager and includes cells, clusters, core groups, and high availability groups. Every high availability group has an associated policy that determines which members of the group are active at a given time.
Cells contain a default core group. Use the administrative console to create additional core groups. A core group cannot extend beyond the boundaries of a cell, and it cannot overlap with any other core groups. A cluster must be a member of only one core group. All of the individual members of that cluster must be members of the same core group. Running members of a core group communicate other running members of that same core group.
Set up a high availability environment
- Enable the high availability manager.
- Create a new policy and associate it with a high availability group.
- Change the policy associated with a high availability group.
- Create a new core group.
- Change the configuration settings for a core group.
While running the applications in a highly available environment, we might want to move core group members to a different core group. We also might want to change one or more of the following:
- The servers designated as preferred coordinators.
- The number of core group coordinators.
- The settings for the discovery protocol, or the failure detection protocol. We might also want to change the version of the protocol.
- Select an alternate protocol provider to use instead of the default Discovery Protocol and Failure Detection Protocol.
- The replication settings for a core group.
- Configure a transport for a core group.
If we are using an IIOP transport, we might also need to complete one or more of the following actions:
- Specify a core group when we add a node.
- Specify a core group when creating an application server.
- Set up a core group bridge.
If we are using multiple core groups and members of different groups need to communicate with each other, we must set up a core group bridge to enable this communication.
- (ZOS) Set up a sysplex that is highly available.
- (ZOS) Control application rollout and workload routing
- (ZOS) Manually update a high availability application.
What to do next
After setting up the product environment to comply with all of the high availability-managed environment rules, use the default core group to control this environment.
Do not add core groups unless the system cannot properly perform without them. Also, do not change the default configurations unless doing so provides the solution to a specific problem. When we do make configuration changes, such as changing the policy for a high availability group or moving core group members between core groups, understand the effect such changes will have on the environment.
If there are issues, see High availability environment troubleshooting tips.
Related:
High availability manager Set up IP addresses for high availability manager communications Specify a preferred server for messaging requests Techniques for Managing Large WebSphere Installations Best Practices for Large WebSphere Topologies (ZOS) Application update procedure in a high availability environment (ZOS) Automatically rolling out updates to a high availability application