Chapter 6 Managing Server Clusters

This chapter describes the concept of clustering iPlanet Web server s and explains how you can use them to share configurations among servers.

• About Clusters
• Preliminary Guidelines for Using Server Clusters
• Setting up a Cluster
• Adding a Server to the Server List
• Modifying Cluster Information
• Removing Servers from a Cluster
• Managing Server Clusters

• create a central place for administering all iPlanet Web Servers
• share one or more configuration files between servers
• start and stop all servers from one "master" Administration Server
• view the access and error logs for the servers you selected

• Install all of the servers you want to include in a particular cluster prior to creating any clusters.
• All servers in a cluster must be iPlanet Web Servers.
• Servers can be installed on any computer in a network, but the "master" Administration Server containing information about the clusters must have access to each cluster-specific Administration Server.
• Any cluster-specific Administration Server can serve as the master administration server.
• The master Administration Server retrieves information about all installed iPlanet Web Servers.
• Make sure all cluster-specific Administration Servers have a username and password that matches one used in the master administration server. You can use the distributed administration feature to set up multiple administrators on each Administration Server. For more information about distributed administration, see Enabling Distributed Administration.
• Make sure all Administration Server are version 4.1 and use the same protocol (HTTP or HTTPS). You'll get an error if you try to add a 3.x Enterprise Server to a cluster, and if you add a 4.1 Administration Server that has 3.x servers, the 3.x servers are not added to the clusters.
• Clusters won't work with 2.x Administration Servers.
• If you change the protocol of one Administration Server in a cluster, you must change the protocols for all Administration Servers, and then you need to update the cluster information by modifying the individual servers in the cluster.

• Set up a cluster
• Add servers to a cluster
• Remove servers from a cluster
• Modify cluster information
• Manage clusters

1. Install the iPlanet Web Servers on the computers you want to include in the cluster. Make sure the Administration Server for the cluster has a username and password that the master Administration Server can use for authentication. You can do this either by using the default username and password or by setting up distributed administration.
2. Install the server that will contain the master Administration Server, making sure the username and password matches the one set in Step 1.
3. Add a server to the cluster list.
4. You can administer a remote server by accessing its Server Manager forms from the cluster form or by copying a configuration file from one server in the cluster to another.

For more information about how to use the Server Manager forms, see Server Manager.

To add a remote server to the list, perform the following steps:

1. Access the Administration Server and choose the Cluster Mgmt tab.
2. Click the Add Server link.
3. Choose the protocol that the remote Administration Server uses. This is the protocol used when contacting the remote Administration Server. Choose http for normal Administration Server. Choose https if the remote Administration Server is secure.
4. Type the hostname for the remote Administration Server. If your DNS can resolve host names, you don't need to type the fully qualified domain name; otherwise type the full host and domain name. For example, type www.mozilla.com.
5. Type the port number that the remote Administration Server uses.
6. Click OK.

The master Administration Server attempts to contact the remote server. When it succeeds, the server identifiers appear on the form for every server installed on the remote administration server. If you have two or more servers on different computers that use the same identifier, the form shows the server identifier and the hostname for the computer. If both server identifier and hostnames are the same, the form shows the port number. If you don't want all of the servers in the cluster, you can remove individual servers.

1. Go to the master Administration Server and choose the Cluster Mgmt tab.
2. Click the Modify Server link.

All servers appear listed by their unique server identifier.

3. Check the servers you want to modify:

1. You can change the information for all servers in the cluster by clicking Select All.
2. Click Reset Selection to unselect any servers you have chosen in the form.
4. Choose the administration server protocol that the remote Administration Server server uses, if it has changed.
5. If applicable, type the new hostname for the remote Administration Server.
6. If applicable, type the new port number that the remote Administration Server uses.
7. Click OK.

1. Go to the master Administration Server and choose the Cluster Mgmt tab.
2. Click the Remove Server link.
3. Check the server you want to remove. You can remove all servers of that type by clicking Select All. Click Reset Selection to unselect all servers.
4. Click OK.

1. Go to the Server Manager forms for the master Administration Server, and then choose the Cluster Mgmt tab.
2. Click the Cluster Control link.
3. Check the server or servers you want to change.

Note that you can select all of the servers in the cluster by clicking Select All. Click Reset Selection to unselect any servers you have chosen in the form.

4. Configure the servers using the form elements specific to the type of server you selected. Most Netscape/iPlanet servers let you start, stop, or restart the server by clicking the corresponding buttons on the form.