Running Applications in a High-Availability Cluster
Most applications can run in an HA cluster environment provided that they have:
Defined start, stop, and monitor procedures
The ability to store the application's state information and data on a shared disk
The ability to survive a crash and restart themselves in a known state
The ability to meet license requirements and host name dependencies
The webMethods Broker application fully meets all of these requirements.
The defined start, stop, and monitor procedures are usually provided as Unix shell scripts that must be incorporated into the cluster control software's infrastructure. Some custom coding will be required to enable the cluster control software to invoke these scripts to control the application.
The cluster control software will determine the health of the resources by periodically probing them using monitor scripts. When the cluster control software determines one of the resources in the cluster has failed, it will shut down the remaining active resources on that cluster node and then start the resources on the spare node.
webMethods Broker provides three Korn shell scripts plus one configuration file for starting, stopping, and monitoring a Broker Server. The scripts and the configuration file are available in the webMethods Broker_directory/scripts/generic_cluster directory.