Revisiting effectiveness of content-aware switching for Web traffic distribution

Over the past few years, there has been significant interest in content-aware routing that use the information found in the payload of packets to provide intelligent content distribution. However, the effectiveness of the idea of content-aware routing is still unclear though these mechanisms have become increasingly important building block for Internet service providers. The aim of this paper is to evaluate the load distribution policies on a production Web cluster with the content-aware routing mechanism. While most of published performance results are measured with simulation or artificial workload in the lab, this is the first performance study using extensive real traffics. We also find a special effect caused by code 304, which may significantly diminish the benefits of the content-aware routing techniques. We then propose a mechanism that can effectively support to shield off the effects.