Chapter 10: Developing High-Performance WebSphere Applications

Overview

This chapter explores a range of hot-list items that developers who develop applications for WebSphere application servers (the majority of application servers, in fact) should consider using to ensure that performance and scalability management is maintained .

It's almost amusing to watch the antics of developers and architects on projects. Quite often, the architect is stereotyped as someone who really doesn't know the details of what he or she is talking about, except at 50,000- foot level. The developer is often stereotyped as someone developing an application against a specification without considering the big picture. Both of these stereo-types are true in some ways, but false in others. My own belief is that a true architect was a developer in a previous life or may still in fact be in a developer-type role (e.g., lead developer, technical lead, etc.). I don't believe you can architect something that you don't have a fundamental understanding of. Also, I don't believe you can be a Java/J2EE architect without knowing how to code and understanding what it is that you preach. I've seen too many cases in which an "architect" has designed a system and has represented it as a construction of pretty boxes and other shapes on single slide of a PowerPoint presentation.

The reason I've included this chapter is to try to help educate readers of this book about some fundamental design considerations that can make a big difference in the performance of an application operating under WebSphere. This chapter consists of 20 rock-solid performance boosters (broken out by tier ) for enterprise J2EE applications that run under WebSphere. This list is by no means exhaustive ”entire books have been written on just this topic. What I've tried to do here is present some of the heavy hitters.

Note  

Most of the design considerations presented in this chapter can be implemented on other J2EE application servers.

It's important to note that this chapter doesn't attempt to explain how to code the specific recommendations. Many of the recommendations are fairly fundamental best practices, but far too often I see them missed or forgotten. I believe this is partly due to the nature of a Java-based application development environment, in which timelines are tight, the language allows for a lot of corner cutting, and there are a number of ways to implement any single component.

My purpose here is to explain what the recommendations are and why you should use them (e.g., what the benefits are), in the context of helping to ensure that your WebSphere environment is well tuned and that the applications that run within it are optimized and coded smartly.

To summarize, each section lists the recommendation and gives it a rating from 1 to 5 for the performance and/or scalability benefit it offers an application operating within a WebSphere environment (with a rating of 1 being the highest benefit and 5 being the lowest benefit) and another rating from 1 to 5 for the implementation complexity (with a rating of 1 being a relatively straight-forward implementation and 5 being a complex implementation effort). These ratings indicate the level of change required for an application and the level of complexity the application's developers will need to adjust to.