Apache runs as a permanent background task: a daemon (UNIX) or service (Windows). Start-up is a slow and expensive operation, so for an operational server, it is usual for Apache to start at system boot and remain permanently up. Early versions of Apache had documented support for an
inetd mode (run from a generic superserver for every incoming request), but this mode was never appropriate for operational use.
The Apache HTTP Server comprises a relatively small core, together with a number of modules (Figure 2-1). Modules may be compiled statically into the server or, more commonly, held in a
/libexec/ directory and loaded dynamically at runtime. In addition, the server ...