Cloud Computing: Google Speeds Up Web-Page Downloads with SPDY Protocol
Pronounced Just As It Appears
SPDY (derived from the word "speedy" rather than an acronym) is a TCP-based application-level protocol for transporting Web content. It is proposed by Google and is being developed as one of their Chromium open-source projects. A white paper on SPDY states that it is intended to augment, rather than replace, HTTP.
SPDY (pronounced "speedy") could become a staple within the next wave of improvements in the Internet and World Wide Web. This is a Google-led, open-source, TCP-based application-level protocol for transporting Web content faster than it has ever traveled before. SPDY is currently in its second year as an experiment run by Google's Chromium group with the simple goal of reducing the latency of Web pages. Speeding Web-page delivery is achieved by prioritizing and multiplexing the transfer of several files so that only one connection per client is required. The average Web-page download entails 28 connections; thus, there is great opportunity for a hiccup somewhere that can slow a page down page loading. Also, in SPDY, all transmissions are encrypted and compressed by design, in contrast to HTTP, where the headers are not compressed. Google Chrome and Chromium browsers already use SPDY when communicating with Google services, such as Google Search, Gmail, Chrome sync and when serving Google's ads. Google acknowledges that the use of SPDY is enabled in the communication between Chrome and Google's SSL-enabled (Secure Sockets Layer-enabled) servers. Up to now, SPDY is limited to the application layer. It does not require kernel changes, and applications do not have to be rewritten. New Web servers and clients are needed, however. Thus, SPDY is still years away from general use. Chromium software engineer Mike Belshe and Cotendo Vice President of Product Strategy Ido Safruti offered an information session on SPDY at the recent O'Reilly Velocity conference in Santa Clara, Calif.; highlights are in this eWEEK slide show.