nginx load balancing strategy and direction proxy principle

nginx’s load balancing strategies can be divided into two categories: built-in strategies and extended strategies. The built-in strategies include weighted polling and ip hash. By default, these two strategies will be compiled into the nginx kernel. You only need to specify the parameters in the nginx configuration. There are many expansion strategies, such as fair, universal hash, consistent hash, etc., which are not compiled into the nginx kernel by default.

First, let’s introduce Nginx’s reverse proxy. Proxy servers are generally divided into forward proxies (often directly called proxy servers) and reverse proxies.

Draw a picture and it will be easier for us to understand.

Forward proxy: It can be imagined as a router, the one through which we want to access the Internet. (It can be said to be the client's proxy)

Reverse proxy: After the client's request comes over, it is handed over to the reverse proxy server, and then the reverse proxy server is handed over to the real server in the background. (This is a server-side proxy)

What we are talking about today is the implementation of nginx’s reverse proxy function. At the same time, reverse proxy can also implement load balancing functions. You can think for yourself.

The above introduces the nginx load balancing strategy and direction proxy principle, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.