Automatic and Dynamic Configuration of Data Compression for Web Servers

HTTP compression is an essential tool for web speed up and network cost reduction. Not surprisingly, it is used by over 95% of top websites, saving about 75% of webpage traffic.

The currently used compression format and tools were designed over 15 years ago, with static content in mind. Although the web has significantly evolved since and became highly dynamic, the compression solutions have not evolved accordingly. In the current most popular web-servers, compression effort is set as a global and static compression-level parameter. This parameter says little about the actual impact of compression on the resulting performance. Furthermore, the parameter does not take into account important dynamic factors at the server. As a result, web operators often have to blindly choose a compression level and hope for the best.

In this paper we present a novel elastic compression framework that automatically sets the compression level to reach a desired working point considering the instantaneous load on the web server and the content properties. We deploy a fully-working implementation of dynamic compression in a web server, and demonstrate its benefits with experiments showing improved performance and service capacity in a variety of scenarios. Additional insights on web compression are provided by a study of the top 500 websites with respect to their compression properties and current practices.