decide on the apache Multi-Processing Module (MPM) choice

[picatz]

If we decide to run an Apache server for our HTTP(s) check, we should configure it. One of the larger configurations we can make is decided the MPM module to use.

We can pick between one of these three modules:

• prefork (default)
• worker
• event

prefork

Implements a non-threaded, pre-forking web server

This Multi-Processing Module (MPM) implements a non-threaded, pre-forking web server. Each server process may answer incoming requests, and a parent process manages the size of the server pool. It is appropriate for sites that need to avoid threading for compatibility with non-thread-safe libraries. It is also the best MPM for isolating each request, so that a problem with a single request will not affect any other.

worker

Multi-Processing Module implementing a hybrid multi-threaded multi-process web server

This Multi-Processing Module (MPM) implements a hybrid multi-process multi-threaded server. By using threads to serve requests, it is able to serve a large number of requests with fewer system resources than a process-based server. However, it retains much of the stability of a process-based server by keeping multiple processes available, each with many threads.

event

A variant of the worker MPM with the goal of consuming threads only for connections with active processing

This Multi-Processing Module (MPM) is based on the worker MPM, which implements a hybrid multi-process multi-threaded server. A single control process (the parent) is responsible for launching child processes. Each child process creates a fixed number of server threads as specified in the ThreadsPerChild directive, as well as a listener thread which listens for connections and passes them to a worker thread for processing when they arrive.

[picatz]

Some benchmarking https://github.com/picatz/goldengirl/issues/5 could be useful to decide.