Analyzing the Traffic Characteristics for Evaluating the Performance of Web Caching

Introduction

Web caching is emerged as a technique to leverage the quality of Web services (Barish & Obraczka, 2000). A proxy cache deployed near to a client serves the Web documents locally as shown in Figure 1. This increases the client side download speed and reduces the outborn traffic. An efficient proxy-cache server can deliver most of the requests from its local cache. The performance of such a service depends on the cache architecture, admission policy, replacement method and cache consistency. Handling the input traffic dynamics is the key aspect in a cache server’s success.

Figure 1.

A proxy-cache server system

In spite of the evolution of new caching schemes and algorithms, the performance of cache services never reached to the expected levels, as can be seen from Table 1, 2 and 3. Suitable setting of the cache performance parameters can provide a solution to this problem. Hit ratio, byte-hit ratio, client side latency and network load reduction (server side and network) are some important cache performance parameters. These parameters can be estimated by analyzing the input traffic stream and Web proxy traces.