| <?xml version="1.0"?> |
| <!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd"> |
| <?xml-stylesheet type="text/xsl" href="../style/manual.xsl"?> |
| <modulesynopsis> |
| <name>worker</name> |
| <description>Multi-Processing Module implementing a hybrid |
| multi-threaded multi-process web server</description> |
| <status>MPM</status> |
| <sourcefile>worker.c</sourcefile> |
| <identifier>mpm_worker_module</identifier> |
| |
| <summary> |
| <p>This Multi-Processing Module (MPM) is the default for most |
| unix-like operating systems. It implements a hybrid |
| multi-process multi-threaded server. Each process has a fixed |
| number of threads. The server adjusts to handle load by |
| increasing or decreasing the number of processes.</p> |
| |
| <p>A single control process is responsible for launching child |
| processes. Each child process creates a fixed number of threads |
| as specified in the <code>ThreadsPerChild</code> directive. The |
| individual threads then listen for connections and serve them |
| when they arrive.</p> |
| |
| <p>Apache always tries to maintain a pool of <em>spare</em> or |
| idle server threads, which stand ready to serve incoming |
| requests. In this way, clients do not need to wait for a new |
| threads or processes to be created before their requests can be |
| served. Apache assesses the total number of idle threads in all |
| processes, and forks or kills processes to keep this number |
| within the boundaries specified by <code>MinSpareThreads</code> |
| and <code>MaxSpareThreads</code>. Since this process is very |
| self-regulating, it is rarely necessary to modify these |
| directives from their default values. The maximum number of |
| clients that may be served simultaneously is determined by |
| multiplying the maximum number of server processes that will be |
| created (<code>MaxClients</code>) by the number of threads |
| created in each process (<code>ThreadsPerChild</code>).</p> |
| |
| <p>While the parent process is usually started as root under |
| Unix in order to bind to port 80, the child processes and |
| threads are launched by Apache as a less-privileged user. The |
| <code>User</code> and <code>Group</code> directives are used to |
| set the privileges of the Apache child processes. The child |
| processes must be able to read all the content that will be |
| served, but should have as few privileges beyond that as |
| possible. In addition, unless <a |
| href="../suexec.html">suexec</a> is used, these directives also |
| set the privileges which will be inherited by CGI scripts.</p> |
| |
| <p><code>MaxRequestsPerChild</code> controls how frequently the |
| server recycles processes by killing old ones and launching new |
| ones.</p> |
| |
| <p>See also: <a href="../bind.html">Setting which addresses and |
| ports Apache uses</a>.</p> |
| </summary> |
| |
| <directivesynopsis location="mpm_common"><name>CoreDumpDirectory</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>Group</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>PidFile</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>Listen</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>ListenBacklog</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>LockFile</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>MaxClients</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>MaxRequestsPerChild</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>MaxSpareThreads</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>MinSpareThreads</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>ScoreBoardFile</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>SendBufferSize</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>ServerLimit</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>StartServers</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>ThreadLimit</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>ThreadsPerChild</name> |
| </directivesynopsis> |
| <directivesynopsis location="mpm_common"><name>User</name> |
| </directivesynopsis> |
| |
| </modulesynopsis> |