John Heidemann / Papers / Performance Interactions Between P-HTTP and TCP Implementations

Performance Interactions Between P-HTTP and TCP Implementations
John Heidemann
USC/Information Sciences Institute

Citation

John Heidemann. Performance Interactions Between P-HTTP and TCP Implementations. [PDF] [alt PDF]

Abstract

This document describes several performance problems resulting from interactions between implementations of persistent-HTTP (P-HTTP) and TCP. Two of these problems tie P-HTTP performance to TCP delayed-acknowledgments, thus adding up to 200ms to each P-HTTP transaction. A third results in multiple slow-starts per TCP connection. Unresolved, these problems result in P-HTTP transactions which are 14 times slower than standard HTTP and 20 times slower than potential P-HTTP over a 10 Mb/s Ethernet. We describe each problem and potential solutions. After implementing our solutions to two of the problems, we observe that P-HTTP performs better than HTTP on a local Ethernet. Although we observed these problems in specific implementations of HTTP and TCP (Apache-1.1b4 and SunOS 4.1.3, respectively), we believe that these problems occur more widely.

Bibtex Citation

@unpublished{Heidemann96b,
  author = {Heidemann, John},
  title = {Performance Interactions Between {P-HTTP} and
                          {TCP} Implementations},
  note = {Released as web page
                    \url{https://ant.isi.edu/lsam/publications/phttp_tcp_interactions/}; submitted to ACM Computer Communications Review,
  		reference superseded by [Heidemann97a]},
  year = {1996},
  sortdate = {1996-07-01},
  project = {lsam},
  jsubject = {www},
  month = jul,
  jlocation = {johnh: folder: lsam},
  keywords = {http, apache, bsd-tcp},
  url = {https://ant.isi.edu/%7ejohnh/PAPERS/Heidemann96b.html},
  psurl = {https://ant.isi.edu/%7ejohnh/PAPERS/Heidemann96b.ps.gz},
  pdfurl = {https://ant.isi.edu/%7ejohnh/PAPERS/Heidemann96b.pdf},
  myorganization = {USC/Information Sciences Institute},
  copyrightholder = {authors}
}
Copyright © by John Heidemann