Apache two MPM prefork and worker differences

Apache defaults to a thread-safe prefork,prefork MPM that uses multiple child processes, each of which has one thread, each processing only one request connection at a time, and one request fails to affect other requests, which is thread-safe

Workers use multi-process multithreading, each with multiple threads, each processing a request connection, with higher performance, but non-thread-safe.

PHP's official recommendation does not use the thread of MPM, that is, threaded MPM, because PHP as a glue language, the dozens of third-party libraries to build a program, if there is a third-party library does not work properly, PHP needs to diagnose the problem and then fix it, When the underlying environment is not each separate process and completely separate memory distribution, there will be many destabilizing factors coming in.

If you need to handle a large number of requests, you can change Apache + mod_php to Nginx + php-fpm.

Http://httpd.apache.org/docs/2.2/mpm.html

http://www.nowamagic.net/librarys/veda/detail/1319/

Apache two MPM prefork and worker differences