Zones are collections of container servers. A container
server can belong only one zone. A container server is assigned to
a zone when it starts.
About this task
You must plan your zones before you start your container
servers because container servers define their zone membership at
startup. If you want to change the zone membership of a container
server, you must restart the server with the new zone information.
Procedure
How you define zones depends on if you are using stand-alone
container servers or container servers that are running within WebSphere® Application Server:
- Define zones for stand-alone container servers.
- Use the -zone parameter of the startOgServer or startXsServer script to specify the zone for all the containers in the started
server. For more information about starting servers, see Starting and stopping stand-alone servers.
- You can also zone names when you are starting container
servers programmatically with the embedded server API. For more information,
see Using the embedded server API to start and stop servers.
- Define zones for container servers that are running within WebSphere Application Server.
You can
use node groups to place container servers in specific zones. Use
the following syntax to name your node group to assign it a zone: ReplicationZone<identifier>. When you define zones
in the deployment policy, you must name the zones exactly as you named
the node groups. The node group name and the zone name in the deployment
policy descriptor XML file must be identical
Important: WebSphere Application Server does not prohibit
nodes from being in multiple node groups. Because container servers
can be only one zone, ensure that your nodes are in exactly one ReplicationZone
node group.
For example, divide four nodes
into two zones, A and B.
- Configure four nodes: node1, node2, node3, and node4, each node
having two servers.
- Create a node group named ReplicationZoneA and a node group named
ReplicationZoneB.
- Add node1 and node2 to ReplicationZoneA and add node3 and node4
to ReplicationZoneB.
- Define ReplicationZoneA and ReplicationZoneB in your deployment
policy descriptor XML file. See Example: Zones in a WebSphere Application Server environment for an example.
- When the servers on node1 and node2 are started, they join ReplicationZoneA,
or zone A in the WebSphere eXtreme Scale configuration. The servers on node3 and node4 join ReplicationZoneB,
as zone B in the WebSphere eXtreme Scale configuration.