In this article the authors propose site-based
mapping schemes for parallel proxy servers that forwards all requests targeting
the same Web site to the same proxy server. The use of parallel proxy servers
requires a mapping scheme to map each client request to a corresponding proxy
server. The basic idea of site-based mapping is that all Web pages belonging to
the same site will be mapped to the same proxy server. The authors propose a
site-based mapping scheme to take advantage of persistent connections. This
scheme can reduce the number of connection establishments, which in turn saves
network bandwidth and shortens user-perceived delay. To gain the advantage of
the persistent connection feature, subsequent requests must be sent to a site
shortly after a connection to it is made. More requests using the active
connection will make the connection better utilized. Unfortunately, the
commonly used mapping schemes are all URL-based. In these schemes, the requests
targeting the same site will probably be mapped and forwarded to different
proxies, resulting in multiple connection establishments to the same site. This
certainly would not optimize the use of persistent connection. With the
site-based scheme, each proxy is configured to be responsible for a particular
set of Web sites. All the requests targeting this set of preconfigured Web
sites are forwarded to the same proxy.