A Study And Application Of SPDY Protocol

HTTP is not designed for latency on multi-resources page, in this context, Google launched,SPDY (pronounced speedy) protocol, as part of the "Let’s make the web faster" initiative,designed for a faster web, reducing page load time. SPDY has been brought to HTTPbis workinggroup as HTTP2.0draft in November2012, and been expected to be finalized in2014, submittedto the IETF as RFC standard.This study is based on SPDY protocol. In this paper, we analyze the SPDY protocol’s framelayer and HTTP layer. Then, we discuss the features of the SPDY protocol, including usingSSL/TLS for security connections, multiplexing streams, request prioritization, HTTP Headercompression and server push. By looking into the implementation of these features, we get acommon understanding of how they reduce the page load time. Finally, we give out a good guessthat in the current network infrastructure, using SPDY, the backoffs of congestion control on TCPlayer will bring more significant impact than multi-connection HTTP.In addition, on the basis of the study, we list the best practices of the SPDY protocol,covering the application level, SSL/TLS layer and TCP layer. Combined with the current web, weknow that SPDY gateway has its advantages of acting the transaction between SPDY-enabledclient and HTTP-only servers. SPDY gateway not only accelerate most of the entire network, butalso guarantee the connection is secure by using SSL/TLS through SPDY proxy regardless ofserver side situation. Finally, in consideration of pages containing multi-domain resources, wedesign a SPDY reverse proxy model to improve page load time by reducing the number of SPDYsessions, and through the introduction of cache, centralized resources bring the more request hits,it can effectively reduce the RTTs, shorten the page load time as a result.Finally, we design and implement two set of prototype systems to test the performance ofSPDY on single-domain resource page and the performance of SPDY reverse proxy on multi-domain resource page, both tested on10Mb and1Gb networks. The results show that when pagecontains50resources, SPDY improves PLT by about40%-85%compared with HTTPS andSPDY reverse proxy gives out17%further improvement then SPDY only, the test results provedthe effectiveness of the SPDY and SPDY reverse proxy.