HTTP/1.0 Persistent Connections: Difference between revisions
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The server may or may not support persistent connections. If the server does support them, it will confirm that by including with the response a "Connection" response header: | The server may or may not support persistent connections. If the server does support them, it will confirm that by including with the response a "Connection: Keep-Alive" response header. httpd also includes a "Keep-Alive" header specifying the persistent connection attributes: the number of seconds it will be kept alive while idle and the maximum number of requests that will be allowed on a persistent connection. | ||
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Connection: Keep-Alive | Connection: Keep-Alive | ||
Keep-Alive: timeout=3600, max=100 | |||
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Once both the client and the server have agreed on using persistent connections, they will keep the underlying TCP/IP connection open, and subsequent requests from that client will be sent over the persistent connection. | Once both the client and the server have agreed on using persistent connections, they will keep the underlying TCP/IP connection open, and subsequent requests from that client will be sent over the persistent connection. | ||
Latest revision as of 23:30, 8 January 2017
Internal
Overview
HTTP/1.0 clients can request a persistent connection by using "Connection: Keep-Alive" header. Early versions of the HTTP/1.1 specification also describe this mechanism.
It is the client that initially requests the connection to be kept alive. The persistent connection is initiated by specifying a "Keep-Alive" value for the "Connection" request header:
GET ... HTTP/1.0 Host: ... Connection: Keep-Alive
The server may or may not support persistent connections. If the server does support them, it will confirm that by including with the response a "Connection: Keep-Alive" response header. httpd also includes a "Keep-Alive" header specifying the persistent connection attributes: the number of seconds it will be kept alive while idle and the maximum number of requests that will be allowed on a persistent connection.
200 OK Content-Length: ... Connection: Keep-Alive Keep-Alive: timeout=3600, max=100
Once both the client and the server have agreed on using persistent connections, they will keep the underlying TCP/IP connection open, and subsequent requests from that client will be sent over the persistent connection.