Using Alternate MPMs

--with-mpm=event --with-mpm=perchild

Apache 2 includes a number of additional MPMs that are classified as experimental. Two of the most interesting ones are the Event MPM and the Perchild MPM. The Event MPM, present only in Apache 2.1, is a variant of the Worker MPM. In this MPM, a separate thread handles all listening sockets and keep-alive connections. This significantly increases scalability, as it allows the remaining threads to process requests instead of waiting for a client to close a connection or issue a new request. This MPM solves some of the issues described in Chapter 10, "Apache Proxy and Caching Support." The Perchild MPM allows Apache to run different virtual hosts under separate user IDs. This can help improve security and provides an alternative to running separate server instances.

In addition to those, the Metux MPM provides an alternative to the Perchild MPM. It can be downloaded from http://www.metux.de/mpm.