Web Caching Performance: How Much Is Lost Unwarily?

Web caching system has been widely deployed to reduce user-perceived latency, network traffic and server load. The performance of web caching relies on cachability of web objects. The availability and duration of an object to be kept in cache are essentially determined by certain HTTP response headers. In this work, we studied the effects of these essential HTTP headers and determine how much cachability is lost due to the absence or improper settings of the headers. Our simulation results indicate that by configuring web servers properly, more than 30% of uncachable objects can be turned cachable and 30—80% of validation process can be avoided. This will lead to a significant improvement on web caching performance.