Summary

This chapter covered some common hardware and software elements found in many production web sites. We discussed various low-level components , such as NICs, routers, and firewalls, which frequently go unnoticed in performance discussions, but nevertheless must be configured properly for your site to operate at peak efficiency. We also discussed more familiar components, such as proxy servers, HTTP servers, application servers, and database servers. The chapter covered their performance issues as well as special considerations such as caching and security.

Finally, we looked not only at your site as it is today but also at how it might grow to support its future traffic burden . The chapter included the trade-offs between vertical and horizontal scaling, as well as some guidelines for selecting servers for your web site.

Having read Chapters 2 and 3, you should now have a basic understanding of how the web application server and the web site function. You should also have a feel for some key tuning points within each of them. In the next chapter, we focus on the key performance issues of the Java virtual machine. Because the application server uses the JVM as its execution platform, JVM performance plays a critical role in your web application's success.