In understanding the performance of your web server and for evaluating the effect of hardware and software configuration options, having a good benchmarking tool is essential. In this section, we describe a number of benchmarking tools that are available for free or for a low cost. We especially concentrate on the Web Capacity Analysis Tool from Microsoft, which we use extensively in the rest of this chapter to illustrate various concepts.
The SPECweb96 is a standardized benchmark for web servers developed by SPEC (Standard Performance Evaluation Corporation). SPEC capitalized on its established expertise in the benchmarking field in developing this benchmark. The objective in the design of this tool was to provide a well-defined workload and environment for testing the performance of web servers so that their relative performance could be compared using a single metric.
The architecture of the SPECweb96 benchmark consists of a prime client and a number of worker clients that generate requests against a web server. In the Unix version, when the program is launched, multiple client processes are created for generating the requests, and the original process becomes the prime, which coordinates the operation of the workers and collects statistics from the test. The Windows NT version is very similar but uses a single multithreaded process instead of multiple processes.
The workload of the benchmark was derived by analyzing logs from several ...