# Overview: Clustering

A WebLogic Server cluster is a deployment in which multiple copies, or instances, of an application work together to provide increased performance, especially in high traffic contexts. In cases where an application receives a high volume of requests, the different instances of WebLogic Server in the cluster share the work of processing the requests. From the client’s point of view, there appears to be only one instance of WebLogic Server servicing the requests.

Clusters also provide failover support. Should one instance of the application fail for some reason--for example, because of a hardware outage--another copy of the application in the cluster can pick up and complete the tasks left incomplete by the failed server.

The server instances that make up the cluster can run on a single machine, or they can run on different machines. Each server instance in a cluster must run the same version of WebLogic Server.

To learn more about deploying applications to WebLogic Server clusters see WebLogic Server Clusters in the WebLogic Server 8.1 Documentation.

Related Topics

Clustering Workshop Applications