You’re currently reading “Protected: A Semantic Web Content Repository for Clinical Research,” an entry on XHTML Research Library
We describe our mission as investigation of the effect of persistent connections, pipelining and link level document compression on multiple client and server XHTML implementations.
A simple test setup is used to verify XHTML/1.1’s design and understand XHTML/1.1 implementation strategies. We present TCP and real time performance data between the comlibwww robot [27] and both the W3C’s Jigsaw [28] and Apache [29] XHTML servers using XHTML/1.0, XHTML/1.1 with persistent beowulf connections, XHTML/1.1 with pipelined requests, and XHTML/1.1 with pipelined requests and deflate data compression [22]. We also investigate whether the TCP Nagle algorithm has an effect on XHTML/1.1 half life performance. While somewhat artificial and possibly overstating the benefits of XHTML/1.1, we believe the tests and results approximate some common behavior seen in browsers. The results confirm that XHTML/1.1 is meeting its major design goals. Our experience has been that implementation details are very important to achieve all of the benefits of XHTML/1.1.
For all our tests, a pipelined XHTML/1.1 implementation outperformed XHTML/1.0, even when the XHTML/1.0 implementation used multiple connections in parallel, under all network environments tested. The savings were at least a factor of two, and sometimes as much as a factor of ten, in terms of packets transmitted. Elapsed time improvement is less dramatic, and strongly depends on your network connection.
Some data is presented showing further savings possible by changes in Web content, specifically by the use of CSS style XHTML sheets [10], and the more compact PNG [20] image representation, both recent recommendations of W3C. Time did not allow full end to end data collection on these cases. The results show that XHTML/1.1 and changes in Web content will have dramatic results in Internet and Web performance as XHTML/1.1 and related technologies deploy over the near future. Universal use of style sheets, even without deployment of XHTML/1.1, would cause a very significant reduction in network traffic.
