HTTP权威指南 读书笔记-- http based on tcp/ip

Http connection management

1. Web browsers talk to web servers over TCP connections

  

2.  Socket communication model

3.  TCP Performance Considerations

   3.1 performance from client perspective

   

    3.2 performance error

        a. DNS lookup

        b. Setup  socket connection:

            TCP Connection Handshake Delays:  the last ACK can with Get/Http request

            

        c. send request 

        d. process request

        e. Respose

        f. rendering the respose to display

  Optimization:

    a.  Delayed Acknowledgments

    b.   TCP Slow Start: the first speed is from slow to fast. 

    c.  Nagle's Algorithm and TCP_NODELAY: the small date may be waitting untial the socket package is full.

    d.  TIME_WAIT Accumulation and Port Exhaustion

         It needs 2MSL (may 2s) to close the socket connectiong, but in some case( performance test) it eat up all the port. It needs to take care.

4.   Serial Transaction Delays

  It is the model that tcp support: 

  Parallel connections: Concurrent HTTP requests across multiple TCP connections

  Persistent connections: Reusing TCP connections to eliminate connect/close delays

  Pipelined connections : Concurrent HTTP requests across a shared TCP connection

  Multiplexed connections:  Interleaving chunks of requests and responses (experimental

 

http close:

http://s99f.blog.163.com/blog/static/35118365200951943541878/