Redundancy of meta search servers in a distributed search engine

We have developed a distributed search engine, called Cooperative Search Engine (CSE), in order to retrieve fresh information. In CSE, a local search engine located in each Web server makes an index of local pages. A meta search server integrates these local search engines in order to realize a global search engine. This meta server is a single point of failure in CSE. So, we propose redundancy of meta search servers in order to increase availability of CSE. In this paper, we describe the reliable architecture of CSE and its evaluations.