The case for persistent-connection HTTP

The success of the World-Wide Web is largely due to the simplicity, hence ease of implementation, of the Hypertext Transfer Protocol (HTTP). HTTP, however, makes inefficient use of network and server resources, and adds unnecessary latencies, by creating a new TCP connection for each request. Modifications to HTTP have been proposed that would transport multiple requests over each TCP connection. These modifications have led to debate over their actual impact on users, on servers, and on the network. This paper reports the results of log-driven simulations of several variants of the proposed modifications, which demonstrate the value of persistent connections.