Manage high availability configurations

Use the deployment manager to administer application server configurations in a cell. A cell includes configurations for these objects:

• Physical hosts on which application servers are installed
• Application servers and other components that comprise the runtime
• Applications installed on application servers
• Resources providing support to applications, such as JDBC drivers and data sources for data access
• Security

A cell retains master configuration files for each server in each node in the cell. Each node and server also has its own local configuration files. Changes to a local node or server configuration file are temporary, if the server belongs to the cell. While in effect, local changes override cell configurations. Changes at the cell level to server and node configuration files are permanent. Synchronization of the configuration files occurs at designated events, such as when a server starts.

Use the deployment manager administrative console to define clusters. Clusters are analagous to WebSphere Application Server Version 4 server groups. A cell can have no clusters, one cluster, or multiple clusters. Vertical clusters have servers on the same node under workload management. Horizontal clusters have servers on multiple nodes under workload management. Workload management routes client requests among application servers in a cluster based on server-weighting. WebSphere Application Server can respond to an increased workload by automatically routing client requests to other nodes as needed. This feature allows you to deploy an application on a single clustered application server in a cluster, without considering workload.