HTTP: The Definitive Guide

For More Information

This completes our overview of the HTTP plumbing trade. Please refer to the following reference sources for more information about TCP performance and HTTP connection-management facilities.

HTTP Connections

http://www.ietf.org/rfc/rfc2616.txt

RFC 2616, “Hypertext Transfer Protocol—HTTP/1.1,” is the official specification for HTTP/1.1; it explains the usage of and HTTP header fields for implementing parallel, persistent, and pipelined HTTP connections. This document does not cover the proper use of the underlying TCP connections.

http://www.ietf.org/rfc/rfc2068.txt

RFC 2068 is the 1997 version of the HTTP/1.1 protocol. It contains explanation of the HTTP/1.0+ Keep-Alive connections that is missing from RFC 2616.

http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-connection-00.txt

This expired Internet draft, “HTTP Connection Management,” has some good discussion of issues facing HTTP connection management.

HTTP Performance Issues

http://www.w3.org/Protocols/HTTP/Performance/

This W3C web page, entitled “HTTP Performance Overview,” contains a few papers and tools related to HTTP performance and connection management.

http://www.w3.org/Protocols/HTTP/1.0/HTTPPerformance.html

This short memo by Simon Spero, “Analysis of HTTP Performance Problems,” is one of the earliest (1994) assessments of HTTP connection performance. The memo gives some early performance measurements of the effect of connection setup, slow start, and lack of connection sharing.

ftp://gatekeeper.dec.com/pub/DEC/WRL/research-reports/WRL-TR-95.4.pdf

“The Case for Persistent-Connection HTTP.”

http://www.isi.edu/lsam/publications/phttp_tcp_interactions/paper.html

“Performance Interactions Between P-HTTP and TCP Implementations.”

http://www.sun.com/sun-on-net/performance/tcp.slowstart.html

“TCP Slow Start Tuning for Solaris” is a web page from Sun Microsystems that talks about some of the practical implications of TCP slow start. It’s a useful read, even if you are working with different operating systems.

TCP/IP

The following three books by W. Richard Stevens are excellent, detailed engineering texts on TCP/IP. These are extremely useful for anyone using TCP:

TCP Illustrated, Volume I: The Protocols

W. Richard Stevens, Addison Wesley

UNIX Network Programming, Volume 1: Networking APIs

W. Richard Stevens, Prentice-Hall

UNIX Network Programming, Volume 2: The Implementation

W. Richard Stevens, Prentice-Hall

The following papers and specifications describe TCP/IP and features that affect its performance. Some of these specifications are over 20 years old and, given the worldwide success of TCP/IP, probably can be classified as historical treasures:

http://www.acm.org/sigcomm/ccr/archive/2001/jan01/ccr-200101-mogul.pdf

In “Rethinking the TCP Nagle Algorithm,” Jeff Mogul and Greg Minshall present a modern perspective on Nagle’s algorithm, outline what applications should and should not use the algorithm, and propose several modifications.

http://www.ietf.org/rfc/rfc2001.txt

RFC 2001, “TCP Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery Algorithms,” defines the TCP slow-start algorithm.

http://www.ietf.org/rfc/rfc1122.txt

RFC 1122, “Requirements for Internet Hosts—Communication Layers,” discusses TCP acknowledgment and delayed acknowledgments.

http://www.ietf.org/rfc/rfc896.txt

RFC 896, “Congestion Control in IP/TCP Internetworks,” was released by John Nagle in 1984. It describes the need for TCP congestion control and introduces what is now called “Nagle’s algorithm.”

http://www.ietf.org/rfc/rfc0813.txt

RFC 813, “Window and Acknowledgement Strategy in TCP,” is a historical (1982) specification that describes TCP window and acknowledgment implementation strategies and provides an early description of the delayed acknowledgment technique.

http://www.ietf.org/rfc/rfc0793.txt

RFC 793, “Transmission Control Protocol,” is Jon Postel’s classic 1981 definition of the TCP protocol.