How to implement load balancing in nginx

Nginx realizes load balancing through polling method, weighted polling method, minimum connection method, IP hashing method, name hashing method and random method. The choice of the appropriate algorithm depends on the needs of the application. For example, stateless applications apply to polling, stateful applications apply to the minimum connection method, and applications requiring session affinity apply to IP hashing or name hashing.

How to implement load balancing in Nginx

Direct answer:

Nginx implements load balancing through the following mechanisms:

Detailed explanation:

1. Polling method:

• Nginx assigns requests to the backend server in order.
• Advantages: Simple and easy to use, each server handles approximately the same number of requests.

2. Weighted polling method:

• Nginx assigns requests based on the server's weights. Servers with higher weights handle more requests.
• Advantages: The load distribution can be adjusted according to the performance or availability of the server.

3. Minimum connection method:

• Nginx assigns requests to servers with the least number of connections.
• Advantages: Ensure server load balancing and prevent individual servers from overloading.

4. IP hashing:

• Nginx hashs the requests based on the client IP address and always assigns requests with the same IP address to the same server.
• Advantages: Ensure session affinity, but requires all servers to have session state.

5. Name hashing:

• Nginx hashs the request based on the requested URL or other fields and always assigns requests with the same hash value to the same server.
• Advantages: Suitable for scenarios where session affinity is required across different URLs.

6. Random method:

• Nginx randomly assigns requests to the backend server.
• Advantages: Simple and fast, but does not guarantee load balancing.

Select the load balancing algorithm:

Choosing the right load balancing algorithm depends on the specific needs of the application:

• Polling and weighted polling methods are suitable for stateless applications.
• The minimum connection method is suitable for stateful applications.
• IP hashing and name hashing are suitable for applications that require session affinity.
• Random method is often used in rapid testing or development environments.

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