Add members to a cluster

You create an application server as a member of a configured cluster.

You must create a cluster if you do not already have a configured cluster.

Overview

If you are migrating from a previous version of WebSphere Application Server, you can upgrade a portion of the nodes in a cell, while leaving others at the other release level. For a time, you might be managing servers that are at a previous release level and servers that are running at the newer release in the same cell.

When you create a cluster, you specify the node on which the first cluster member resides. In a mixed cell environment, you can use any server from within that node group to create a new cluster member. For example, if the node group to which the cluster belongs consists of a v6.1 node, and a v5.1, you can use a server from either the v5.1 or the v6.1 node to create a new cluster member.

To create a new cluster member, view information about existing cluster members, or manage existing cluster members:

Procedure

1. In the administrative console, click Servers > Clusters > cluster_name > Cluster members. The Cluster members page lists members of a cluster, and for each member indicates:

   • The node on which the member resides.

   • The version of the application server. This information shows whether the cluster is a mixed cluster.

   • The configured weight for the member.

   • The runtime weight for the member. This weight indicates the proportionate workload that is currently directed to this cluster member.

   • Whether the member is started, stopped, or encountering problems.

2. Click New to create a new cluster member.

   Clicking New starts the Create a new cluster member wizard. This wizard allows you to add new members to an already configured cluster.

   A copy of the first cluster member that you create is stored as part of the cluster data and becomes the template for all additional cluster members that you create. In a mixed environment, there is a separate template for each node version that is part of the cluster. For example, if the cluster includes a v5.1 node and a v6.1 node, a v5.1 and a V6.1 template is created. When you create a new cluster member, the node you select for the cluster members determines which template is used to create the cluster member.

   1. Specify a name for the cluster member (application server). The name must be unique within the node.

   2. Select the node for the cluster member.

   3. Specify the server weight. The weight value controls the amount of work that is directed to the application server. If the weight value for the server is greater than the weight values that are assigned to other servers in the cluster, then the server receives a larger share of the workload. The value can range from 0 to 20.

   4. Specify whether to generate unique HTTP ports.

   5. Click Add Member to finish defining the cluster member. The first cluster member for this cluster is used as the template for this cluster member. You can repeat these steps to define other cluster members.

   6. When you finish defining additional cluster members, review the summary information for the new cluster members. If you have to change any of the property settings for any of the new members, select that cluster member, and then click Edit. When you finish changing the property settings, click Update Member to save your changes.

   7. When you finish defining new cluster members, click Next to view the summary page for the cluster, and then click Finish to create these new cluster members.

3. Click Review, select Synchronize changes with Nodes, and then click Save to save your changes.

Results

What to do next

If when you created the new members, you chose to generate unique ports, update the alias list for the virtual host that you plan to use with the new servers.

You can:

• Click on the name of the cluster member under Member name on the Cluster members page in the administrative console, and examine the settings for a specific cluster member.

• Click Servers > Application Servers > cluster_member_name or click Servers > Clusters > cluster_name > Cluster members > cluster_member_name to specify additional application server properties for a cluster member.

• Create a backup cluster. See Creating backup clusters for more information.

• Start the cluster. See Starting clusters for more information.

• Use scripting to automate the task of adding cluster members.

Related concepts

Related tasks