APPROXIMATE ANALYSIS AND MEASUREMENT OF EQUIVALENT MODEL FOR TREE CONNECTION OF WEB SERVER SYSTEMS

摘要

In this paper we propose a method to estimate the system performance before constructing the tree connection of a Web server system, which means all nodes have exactly zero or two childes and haven't loops; we aim at a serial-parallel connection by carrying on simulation, analysis equation and measurement. We analyze the arrival rate with respect to the service rates where there are three kinds of relation - greater than, equal to and less than - which requires 27 cases or regions to represent the complex model of a complicated system using equivalence. For the physical verification we install a Web server system represented by a serial-parallel queue. We use measurement software to measure the system response time of the Web page access, and we find that the equivalent service rate of the actual measurement by linear regression estimate. The equivalent service rate is 54 requests/sec by the specific experimental measurement, and at 48.21 requests/sec we compute the difference between the two service rates as 10.85%. In the actual measurement, if we use a Web page data size of 25K bytes, measure the system response time and compute the equivalent system response time, the difference between them is 46.12%.