Server selection algorithms allow Web clients to select one of the replicated servers which is "close" to them and thereby minimize the response time of the Web service. Using proxy server traces containing more than fifteen thousand client requests, we compared the effectiveness of several "proximity" metrics including the number of hops between the client and server, the ping round trip time and the HTTP request latency. Based on this analysis, we designed two new algorithms for selection of replicated servers and compared their performance against the existing algorithms.
Caching at proxy servers is one of the ways to reduce the response time perceived by Web users. Cache replacement algorithms play a central role in the response time reduction by selecting a subset of documents for caching. We developed a unified cache maintenance algorithm, LNC-R-W3-U (Least Normalized Cost Replacement for the Web with Updates), which integrates both cache replacement and consistency algorithms.
This project was supported by NASA and supported 5 Ph.D. students (one female). This has resulted in 2 conference papers, and one journal submission.