Design and implementation of a Layer-7 MPLS-based Web Switching Architecture

During recent years web servers evolved from providing simple, static content to offering different services and a variety of dynamically generated pages and objects. Consequently, scalability and load-balancing have emerged as main requirements for modern web farms. A common solution is based on placing a Web Switch in front of the web servers; the switch acts as a dispatcher that redirects user requests according to desired criteria. In this paper we describe a novel web switching architecture, based on the MPLS technology and on Open-Source software. The switching decision is primarily made considering Layer-7 information, thus achieving flexible content-based routing to the most appropriate server. State information from the web servers such as, for example, load average and resource availability is considered as well. The architecture here proposed has been implemented as a free software project using MPLS-enabled Linux workstations.