6.2 WebSphere workload management defined

Workload management is implemented in IBM WebSphere Application Server Network Deployment V6 by using application server clusters and cluster members. These cluster members can all reside on a single node (system) or can be distributed across multiple nodes (or LPARs).

You might have Web clients or thick Java/C++ clients. When using clustered WebSphere Application Servers, your clients can be redirected either automatically or manually (depending on the nature of the failure) to another healthy server in the case of a failure of a clustered application server.

Workload management (WLM) is the WebSphere facility to provide load balancing and affinity between application servers in a WebSphere clustered environment. It optimizes the distribution of processing tasks in the WebSphere Application Server environment. Incoming work requests are distributed to the application servers that can most effectively process the requests.

Workload management is also a procedure for improving performance, scalability, and reliability of an application. It provides failover when servers are not available. WebSphere uses workload management to send requests to alternate members of the cluster. WebSphere also routes concurrent requests from a user to the application server that serviced the first request, as EJB calls, and session state will be in memory of this application server.

WLM is most effective when the deployment topology comprises application servers on multiple machines, because such a topology provides both failover and improved scalability. It can also be used to improve scalability in topologies where a system comprises multiple servers on a single, high-capacity machine. In either case, it enables the system to make the most effective use of the available computing resources.

Two types of requests can be workload managed in IBM WebSphere Application Server Network Deployment V6:

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