The warm standby topology consists of an application server
environment that is supported by a secondary installation on a highly
available shared disk.
In a warm standby topology, one instance of WebSphere® Application Server is
active, in active-passive mode. Cluster management software,
such as System
Automation for Multiplatforms,
allows failover to a secondary WebSphere Application Server installation
on a shared disk.
The system environment consists of the following
highly available components:
- WebSphere Application Server and IBM® HTTP Server are
automated to run on a primary server and a standby server, which is
assisted by cluster management software. If the primary server fails,
services can be restored by mounting the shared disk instance on the
standby server and starting the services there. The application is
accessed through a Service IP that is applied to the active system
only.
- The database server can be automated to run on a primary database
server and a standby database server. Automation and data integrity
is handled by DB2® HA Feature for LUW.
If the primary database server fails, the services are automatically
restored on the standby database server.
- Tivoli® Directory Server can
be automated to run on a primary server and a standby server. If the
primary server fails, the standby server takes over the Tivoli Directory Server operations.
The directory server manages data replication by using peer-to-peer
replication. Cluster management software, such as System
Automation for Multiplatforms,
creates high availability without a proxy server.
The following diagram shows a warm standby topology, where
a product such as Maximo® Asset Management is
deployed in a scaled WebSphere Application Server environment.
Standby servers provide failover support for each component
and shared disk storage maintains data integrity. As individual components, WebSphere Application Server,
the HTTP server, the database server, and the directory server are
all highly available.
