8.1 Clustering for performance overview

The term "clustering" in regard to performance refers to scaling multiple copies of an application so it is able to service more requests than a single copy of the application would be.

Making an entire system performant means tuning, "tweaking" and finding the bottlenecks in all of the supporting infrastructure and back-end connections. WebSphere may often be blamed for performance issues that are in fact caused by completely separate systems.

This chapter focuses on methods of scaling WebSphere Application Server to improve performance by exploiting available resources. It specifically does not cover tuning any other part of the infrastructure on which the system relies, and which may cause the system as a whole to underperform.