Timed redirection: HTTP request coalescing to reduce energy use of hybrid web servers

Abstract

Network protocols can be designed to enable a reduction in energy use of data servers. We architect a new HTTP timed redirection response for a GET request to be redirected to another server with a given delay. This redirection response can be used in a hybrid web server to coalesce GET requests and allow a server to periodically sleep. In such a hybrid web server, a small low-power ARM-based Assistant receives all incoming HTTP requests and redirects them to a Pentium-class Master server with a delay calculated to allow the Master to sleep in alternating intervals. There is a growing class of applications that are delay tolerant at short time scales for file downloads. Experimental evaluation of timed redirection shows significant savings for the Master server with added delay for some requests which may be acceptable for certain applications.