Apache - Multi-Processing Modules (MPMs)

MPMs are Responsible for binding to network ports on the machine, accepting requests, and dispatching children to handle the requests. For Linux, two types: worker (threaded MPM) and prefork (non-threaded MPM)

	worker MPM	prefork MPM
How it works	Uses multiple child processes. It's multi-threaded within each child, and each thread handles a single connection.	Uses multiple child processes, each child handles one connection at a time.
Fast	fast and highly scalable	speed is comparable to that of worker
Memory	Memory footprint is comparatively low	Memory usage is high, and more traffic leads to greater memory usage
Stability	less tolerant of faulty modules, and a faulty thread can affect all the threads in a child process.	highly tolerant of faulty modules and crashing children
Suited for	multiple processors	single or double CPU systems