Modular TCP handoff design in STREAMS-based TCP/IP implementation

Abstract

Content-aware request distribution is a technique which takes into account the content of the request when distributing the requests in a web server cluster. A handoff protocol and TCP handoff mechanism were introduced to support content-aware request distribution in a client-transparent manner. Content-aware request distribution mechanisms enable the intelligent routing inside the cluster to provide the quality of service requirements for different types of content and to improve overall cluster performance. We propose a new modular TCP handoff design based on STREAMS based TCP/IP implementation in HP-UX 11.0. We design the handoff functions as dynamically loadable modules. No changes are made to the existing TCP/IP code. The proposed plug-in module approach has the following advantages: flexibility-TCP handoff functions may be loaded and unloaded dynamically, without node function interruption; modularity- proposed design and implementation may be ported to other OSes with minimal effort.