Monitor

and tune Web servers

Our topology addresses Web server performance in two ways:

• Separate the Web server tier from the application server tier for security and performance reasons.

The Web server machines are typically placed in a DMZ, with one network interface connected to the outbound firewall and a second network interface connected to the inbound firewall and the application server tier behind it (see topology overview in Figure 3-1). The application server tier is better protected against direct malicious attacks from the Internet. Another reason for separating the Web tier is to permit independent scaling and tuning of Web (I/O intensive) and application (CPU intensive) layers. Unlike the sample topology used in this book, often fewer Web servers than application servers are required to support a given Commerce workload.

By separating Web servers and application servers, the workload is distributed to separate machines, yielding increased performance compared to a single tier installation.

• Run multiple Web servers for High Availability and performance reasons. Run enough Web servers so that there is enough capacity for managing peak workloads even when one Web server experiences a planned or unplanned outage.

In this chapter, we describe how to monitor and tune the performance of each Web server to support maximum end-to-end throughput and capacity for your WebSphere Commerce application.

We also describe how the IBM HTTP Server Plug-in for WebSphere Application Server can be tuned.

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