Reverse proxy

A reverse proxy is a proxy server that is installed in the neighborhood of one of more webservers. All connections coming from the Internet addressed to one of the webservers are serviced through the proxy server, which may either entirely deal with the request itself, or pass the request wholly or partially to the main webserver.

There are several reasons for installing reverse proxy servers:

• Security: the proxy server is an additional layer of defense and therefore protects the webservers further up the chain
• Encryption / SSL acceleration: when secure websites are created, the SSL encryption is sometimes not done by the webserver itself, but by a reverse proxy that is equiped with SSL acceleration hardware. See Secure Sockets Layer.
• Load distribution: the reverse proxy can distribute the load to several webservers, each webserver serving its own application area. In such a case, the reverse proxy may need to have to rewrite the URL's in each webpage (translation from externally known URLs to the internal locations)
• Serve/cache static content: A reverse proxy can offload the webservers by caching static content like pictures and other static content. Proxy caching of this sort can often satisfy 70% or more of website requests, greatly reducing the load on the central web server.

See also

• Squid cache
• main article at proxy server, from a version of which the original text of this article was taken.