Nginx

NGINX is a webserver used for proxying caching and load balancing with HTTP server capability. 

 

• The master process performs the privileged operations such as reading configuration and binding to ports, and then creates a small number of child processes (the next three types).
• The cache loader process runs at startup to load the disk‑based cache into memory, and then exits. It is scheduled conservatively, so its resource demands are low.
• The cache manager process runs periodically and prunes entries from the disk caches to keep them within the configured sizes.
• The worker processes do all of the work! They handle network connections, read and write content to disk, and communicate with upstream servers.

Each worker process is single‑threaded and runs independently, grabbing new connections and processing them. The processes can communicate using shared memory for shared cache data, session persistence data, and other shared resources. 

https://www.nginx.com/blog/inside-nginx-how-we-designed-for-performance-scale/