Server cluster settings

Use this page to view or change the configuration of a server cluster instance, and to view the local topology of a server cluster instance.

To change the configuration and local topology of a server cluster, in the administrative console click Servers > Clusters > Clusters > cluster_name.

To view runtime information, such as the state of the server cluster, click Servers > Clusters > WebSphere application server clusters > cluster_name, and then click the Runtime tab.

To display the topology of a specific cluster, click Servers > Clusters > WebSphere application server clusters > cluster_name, and then click the Local Topology tab.

If the high availability infrastructure is disabled and you require IIOP routing capabilities, follow the instructions contained in the Enabling static routing for a cluster topic to create a static route table. This table enables the cluster to handle IIOP requests.

Avoid trouble:

Because the information contained in the static route table does not account for server runtime state, you should only use this option if the high availability infrastructure is disabled.
Use of a static route table preempts the use of the dynamic routing table that is contained in cluster members. After the static file is transferred to a node, whenever a cluster member residing in that node starts, that cluster member uses the static table instead of the dynamic table to handle IIOP routing. If a cluster member is running when you create the static route table, then you must restart that cluster member to give that cluster member access to the static route table information, because the table content is loaded at run time.
After the table is created, an informational message, similar to the following message, is issued that indicates the name of the file that contains the table and where that file is located:
```
The route table for cluster MyCluster was exported to file
/home/myInstall/was/server/profiles/dmgrProfile/config/cells/
   MyCell/clusters/Myfile.wsrttbl.
```
As this message indicates, the file containing the static route table is placed in the config directory of the deployment manager for this cluster. Keep a record of this location so that you can delete this file when you are ready to start using dynamic routing again.
If you set up a static route table, then you must statically set the ORB_LISTENER_ADDRESS port on each of the cluster members because the route table is static, and the cluster members do not communicate during state changes. If this port is not assigned, then the cluster members restart on different ports, and the static routing information is not able to route requests to the cluster members.

Cluster name

Specifies a logical name for the cluster. The name must be unique among clusters within the containing cell.

Short name

Specifies the short name for this cluster. This field displays only if you are running on z/OS®.

The short name is used as the WLM APPLENV name for all servers that are part of this cluster.

If you specify a short name for a cluster member, the name:

Must be one to eight characters in length
Must contain only uppercase alphanumeric characters
Cannot start with a number
Must be unique in the cell

If you do not specify a short name, then the system assigns a default short name that is automatically unique within the cell. You can change the generated short name to conform with your naming conventions.

Unique Id

Specifies the unique ID of this cluster.

The unique ID property is read only. The system automatically generates the value.

Bounding node group name

Specifies the node group that forms the boundaries for this cluster. All application servers that are members of a cluster must be on nodes that are members of the same node group.

A node group is a collection of application server nodes. A node is a logical grouping of managed servers, usually on a system that has a distinct IP host address. All application servers that are members of a cluster must be on nodes that are members of the same node group. Nodes that are organized into a node group need enough capabilities in common to ensure that clusters formed across the nodes in the node group can host the same application in each cluster member. A node must be a member of at least one node group and can be a member of more than one node group.

Create and manage node groups by clicking System administration > Node groups in the administrative console.

Prefer local

Specifies that the host scoped routing optimization is enabled or disabled. The default is enabled, which means that, when possible, enterprise bean requests are routed to the client host. Enabling this setting improves performance because client requests are sent to local enterprise beans.

[z/OS] This field does not apply for z/OS.

Information	Value
Data type	Boolean
Default	true

Supported configurations: If you enable the preferLocal optimization, the deployment manager must be running to affect the configuration. If the deployment manager is shut down, preferLocal optimization is not performed and requests might be dispersed across all the members of the cluster.

Enable failover of transaction log recovery

Specifies that for the transaction service component, failover of the transaction log for recovery purposes is enabled or disabled. The default is disabled.

When this setting is enabled, and the transaction service properties required for peer recovery of failed application servers in a cluster are properly configured, failover recovery of the transaction log occurs if the server processing the transaction log fails. If the transaction services properties required for peer recovery of failed application servers in a cluster are not properly configured, then this setting is ignored.

wlcID

Specifies the currently registered workload controller (WLC) identifier for the cluster. This setting might not display for all configurations.

Information	Value
Data type	String

State

Specifies whether the cluster is stopped, starting, or running.

If all cluster members are stopped, the cluster state is stopped. After you request to start a cluster, the cluster state briefly changes to starting and each server that is a member of that cluster launches, if it is not already running. When the first member launches, the state changes to websphere.cluster.partial.start. The state remains partially started until all cluster members are running, then the state changes to running. Similarly, when stopping a cluster, the state changes to partially stopped as the first member stops and changes to stopped when all members are not running.

Information	Value
Valid values	starting, partially started, running, partially stopped, or stopped.