FreeBSD Reverse Proxy load Balancing

As mentioned earlier, using a proxy server can forward requests to an internal Web server, and using this acceleration pattern can obviously improve the access speed of static Web pages. However, it is also possible to consider a technique that uses a proxy server to forward requests evenly to multiple Web servers to achieve load balancing purposes.

A member of the Apache Development Group Ralf S.engelschall Proxy module based on Apache Mod_proxy developed a reverse proxy module mod_rproxy to achieve load balancing.

This proxy method is different from the normal proxy way, the standard proxy method is that the customer uses the proxy to access multiple external Web servers, and this proxy method is to proxy multiple clients to access the internal Web server, so also known as reverse proxy mode. Squid's accelerated mode is similar to this, but does not achieve a balanced setting for multiple internal servers. While this task is not particularly complex to achieve, it is not very simple to achieve because of the particularly high efficiency required.

The advantage of using reverse proxies is that you can combine load balancing with the proxy server's caching technology to provide useful performance. However, it is not a small problem, the first is that each service must be dedicated to the development of a reverse proxy server, this is not an easy task. And, although the proxy server itself can be designed very high efficiency, but each for each agent, the proxy server must maintain two connections, an external connection, an internal connection, so for particularly high connection requests, the proxy server load is very large. It is likely that the end of the reverse proxy server has become a service bottleneck.