Summary Cache: A Scalable Wide-Area Web Cache Sharing Protocol

Abstract—The sharing of caches among Web proxies is an important technique to reduce Web traffic and alleviate network bottlenecks. Nevertheless it is not widely deployed due to the overhead of existing protocols. In this paper we demonstrate the benefits of cache sharing, measure the overhead of the existing protocols, and propose a new protocol called “summary cache.” In this new protocol, each proxy keeps a summary of the cache directory of each participating proxy, and checks these summaries for potential hits before sending any queries. Two factors contribute to our protocol’s low overhead: the summaries are updated only periodically, and the directory representations are very economical, as low as 8 bits per entry. Using trace-driven simulations and a prototype implementation, we show that, compared to existing protocols such as the internet cache protocol (ICP), summary cache reduces the number of intercache protocol messages by a factor of 25 to 60, reduces the bandwidt...

• Type: Conference
• Year: 1998
• Where: SIGCOMM
• Authors: Li Fan, Pei Cao, Jussara M. Almeida, Andrei Z. Broder
• Keywords: Communications, Internet Cache Protocol, Protocol’s Low Overhead, SIGCOMM 1998, Summary Cache