To alleviate this problem, web caches have been developed to reduce the amount of traffic and delays on the Internet. However, as caches may be distributed around the world, maintaining cache coherency while not generating excess data traffic, which negates the purpose of caches, is of great importance. Belloum and Hertberger present an overview of the difficulties of maintaining cache coherency in a distributed environment. Through the use of simulation experiments, the authors demonstrate the impact of different factors on Web cache coherence. The papers presented here represent just a small part of the rich research environment presented by the Internet.
Many more topics await investigation, promising to keep researchers busy for decades to come.