A cluster is a group of Sun Java System Web Servers that can be administered from a single Administration Server. Each cluster must include one server designated as the administration server. If you have more than one cluster, you can administer all clusters from a single “master” Administration Server. The master administration server retrieves the information about all the clusters and provides the interface for managing the Sun Java System Web Servers installed in their respective clusters.
Here are some of the tasks you can accomplish by organizing your servers into clusters:
Create a central place for administering all Sun Java System 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
You can specify a master Administration Server for administering all of your clusters by clustering your Sun Java System Web Server.
Individual servers can be installed on any computer in a network, but the Administration Server that you designate as the “master” contains information about all clustered servers, and must have access to each cluster’s individual Administration Server.