Towards better performance measurement of Web servers

Performance evaluation is an important issue in building efficient Web servers. It is desirable to measure the performance regularity of Web servers for overall performance behavior of the system in the full spectrum of working area, which is generally overlooked and has not received proper attention. In this paper we aim to raising the awareness of the importance of the performance regularity of a Web server by introducing Gini performance coefficient (GPC) as a scale-invariant metric for measuring the performance regularity. We present the theorems that relate the performance regularity of a Web server to the GPC, thereby providing a quantitative yardstick that complements the system capacity metric such as maximum throughput for measuring the system performance. Several representative systems that were used in the public benchmark study are examined under the proposed metric. The results are completely in line with our theoretical analysis.