Nginx HTTP Server - Fourth Edition

Relieving worker processes

In the case of websites that require heavy I/O operations, such as file uploads or downloads, the asynchronous architecture of Nginx can present a certain disadvantage: while the master process is able to absorb incoming connections asynchronously, worker processes can be blocked for relatively long periods of time by certain tasks (the most common of which is reading data from hard disk drives or network drives).

Consider a simplified configuration with two worker processes; each HTTP request received by Nginx gets assigned to either process. Within a process, operations are performed sequentially: receiving and parsing the request, reading the requested file from its storage location, and finally, preparing and ...