What is the working mechanism of nginx?

The working mechanism of nginx is an asynchronous, non-blocking, event-driven model.

Specifically, nginx employs a main process to oversee multiple worker processes, each responsible for handling client requests. The main process listens on one or multiple ports, accepts client connection requests, and forwards these requests to the worker processes as events.

In the working process, nginx utilizes multiplexing technology to handle multiple requests simultaneously. By using system calls such as epoll, kqueue, or select, nginx can monitor the read and write events of multiple connections at the same time, and respond accordingly based on the arrival of these events. Instead of creating a thread or process for each request, nginx processes requests using an event-driven approach when they arrive.

nginx’s worker processes are non-blocking, meaning that when a request requires an I/O operation, the worker process does not wait indefinitely for the I/O operation to complete. Instead, it places the request in a waiting queue and continues to process other requests. When the I/O operation is finished, nginx will use events to wake up the request and continue processing it.

The asynchronous, non-blocking working mechanism enables Nginx to efficiently handle a large number of concurrent connections, improving the system’s throughput and response speed. Additionally, Nginx’s working process model effectively utilizes system resources, avoiding the overhead of creating and destroying threads or processes.