7.1 Clustering WebSphere for availability"Clustering" is a fundamental approach for accomplishing high availability. IBM WebSphere Application Server Network Deployment V6 offers a built-in appserver clustering function and the HAManager for protecting WebSphere singleton services. Clustering appservers provides workload management and failover for applications that reside on the appserver cluster. It is also possible to use external clustering software such as HACMP to provide availability clustering for WebSphere Application Server. These two kinds of cluster failovers can be categorized as follows:
Usually, IP-based cluster failover is slower (taking one to five minutes), and non-IP cluster failover is very fast (instantaneous). WebSphere V6 HAManager does not require extra software. However, IP cluster failover still relies on cluster software such as HACMP to provide the cluster information. |
