Create a cluster: Create additional cluster members
Create additional members for a cluster. We can add a member to a cluster when we create the cluster or after we create the cluster. A copy of the first cluster member that we create is stored as part of the cluster data and becomes the template for all additional cluster members that we create.
To add members to a cluster, in the administrative console, click...
Servers > Clusters > WebSphere application server clusters > cluster_name > Cluster members > New. After you enter the required information about the new cluster member, click Add Member to add this member to the cluster member list.
After adding a cluster member, we might need to change one or more of the property settings for this cluster member, or another cluster member that we just added. To change one or more property settings for any cluster member that we just added, other than the first cluster member, select that cluster member> Edit. When we finish changing the property settings, click Update Member to save the changes.
If we decide not to create a particular cluster member, select the member and then click Delete.
We cannot edit or delete the first cluster member or an already existing cluster member.
If we create additional cluster members immediately after we create the first cluster member, the list of cluster members includes a checklist in front of the names of these additional cluster members. However, a check box does not appear in front of the name of the first cluster member because we cannot delete this member or edit its settings. To modify the first cluster member, click Previous.
Similarly, if we are adding cluster members to a cluster that already has existing members, the existing members appear in the list of cluster members but a check box does not appear in front of the names of these cluster members. To delete one of these existing members or to change the settings of one of these cluster members, in the administrative console click Servers > Clusters > WebSphere application server clusters > cluster_name > Cluster members, and then select the member to delete or whose configuration settings we want to change.
Member name
Name of the application server created for the cluster.
The member name must be unique on the selected node.
Select node
Node on which the application server resides.
(Dist) In a mixed cell environment, we can use any server from within the node group to create a new cluster member. For example, if the node group to which the cluster belongs consists of a Version 7.0 node and a v6.1 node, we can use a server from either the v7.0 node or the v6.1 node to create a new cluster member.
(ZOS) Short name
Short name for this cluster member. This field only displays if we are running on z/OS .
The short name is the default z/OS job name and identifies the cluster member to the native facilities of the operating system, such as Workload Manager (WLM), Automatic Restart Manager, SAF (for example, RACF ), started task control, and others.
If we specify a short name for a cluster member, the name:
- Must be one to eight characters in length. By default, the product assumes that we are using a 7-character server short name (JOBNAME). If our naming standards require 8 characters, we can lengthen the 7-character server short name to 8 characters.
- Must contain only uppercase alphanumeric characters
- Cannot start with a number
- Must be unique in the cell
- Cannot be the same as the value specified on the ClusterTransitionName custom property of any non-clustered server. Do not specify a cluster transition name for a server that is part of a cluster.
If we do not specify a short name, the system assigns a default short name that is automatically unique within the cell. We can change the generated short name to conform with your naming conventions.
Weight
Amount of work that is directed to the application server.
If the weight value for the server is greater than the weight values assigned to other servers in the cluster, the server receives a larger share of the cluster workload. The value can range from 0 to 20. Enter zero to indicate that we do not want requests to route to this application server unless this server is the only server available to receive requests.
(ZOS) On z/OS, weight is used to balance some of the workload types, but others are balanced by the z/OS system.
- For HTTP requests, weights are used to distribute HTTP traffic between the web server plug-in and the controller handling the clustered application server. Assign a higher weight value to the application server that should receive the HTTP traffic.
- For web services calls, information is transferred from a servant in one application server to a controller in another application server. The application server that receives the call has the highest weight value.
- Weight has no affect on Internet Inter-ORB Protocol (IIOP) requests. IIOP requests are distributed to the correct application server using the sysplex distributor.
Generate unique HTTP ports
That a unique HTTP port is generated for the application server. By generating unique HTTP ports for the application server, you avoid potential port collisions and configurations that are not valid.
Related:
Clusters and workload management Create clusters Modifying cluster member templates Create a cluster: Basic cluster settings Create a cluster: Create first cluster member Create a cluster: Summary settings