Nginx load balancing configuration practice to improve website availability

Nginx load balancing configuration practice to improve website availability

Abstract: Nginx is a high-performance web server and reverse proxy server. Through load balancing configuration, requests can be distributed to multiple back-end servers. Improved website usability and performance. This article will introduce how to configure Nginx load balancing and use sample code.

1. What is load balancing?

Load balancing is a technology that distributes requests to multiple servers. By evenly distributing the load, the stability and performance of the system can be improved. Load balancing can improve the availability of the website. When a backend server fails, other servers can still provide services normally.

2. Nginx load balancing configuration

Nginx can configure load balancing through the upstream module. We can add the following configuration to the Nginx configuration file (usually /etc/nginx/nginx.conf):

http {
    upstream myapp {
        server backend1.example.com;
        server backend2.example.com;
        server backend3.example.com;
    }
    
    server {
        listen 80;
        
        location / {
            proxy_pass http://myapp;
        }
    }
}

In the above configuration, we define an upstream block named myapp, which contains multiple The address of a backend server. In the server block, we forward the request to myapp through the proxy_pass directive.

3. Load balancing strategy

Nginx supports multiple load balancing strategies, such as polling (default strategy), IP hashing, least connections, etc. We can configure the policy by adding relevant directives in the upstream block. The following are examples of several commonly used load balancing strategies:

• Polling strategy:

  upstream myapp {
    server backend1.example.com;
    server backend2.example.com;
    server backend3.example.com;
  }

• IP hash strategy:

  upstream myapp {
    ip_hash;
    server backend1.example.com;
    server backend2.example.com;
    server backend3.example.com;
  }

• Least connection strategy:

  upstream myapp {
    least_conn;
    server backend1.example.com;
    server backend2.example.com;
    server backend3.example.com;
  }

4. Load balancing sample code

In order to better understand Nginx load balancing Configuration, a practical example is given below. Suppose we have three backend servers that serve a web application. We can configure it according to the following steps:

• Step 1: Deploy the web application on each backend server and listen on different ports.
• Step 2: Configure load balancing on the Nginx server.

Nginx configuration file example (/etc/nginx/nginx.conf):

http {
    upstream myapp {
        server backend1.example.com:8000;
        server backend2.example.com:8000;
        server backend3.example.com:8000;
    }
    
    server {
        listen 80;
        
        location / {
            proxy_pass http://myapp;
        }
    }
}

In the above example, we assume that each backend server listens on port 8000. By forwarding the request to myapp, Nginx automatically selects a backend server to handle the request.

5. Summary

Through Nginx's load balancing configuration, we can evenly distribute website requests to multiple back-end servers to improve website availability and performance. This article introduces the configuration method of Nginx load balancing and provides sample code. I hope readers can learn from this article how to implement load balancing configuration through Nginx and improve website availability in practical applications.

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