<hr/><h2><aname="ProxyBlock">ProxyBlock</a><aname="proxyblock">Directive</a></h2><tablecellpadding="1"cellspacing="0"border="0"bgcolor="#cccccc"><tr><td><tablebgcolor="#ffffff"><tr><tdnowrap="nowrap"><strong>Description: </strong></td><td>Words, hosts, or domains that are banned from being
<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
<ahref="mpm_common.html#user"class="directive"><codeclass="directive">User</code></a> and <ahref="mpm_common.html#group"class="directive"><codeclass="directive">Group</code></a> 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 <ahref="../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
--><title>prefork- Apache HTTP Server</title><linkhref="../style/manual.css"type="text/css"rel="stylesheet"/></head><body><blockquote><divalign="center"><imgsrc="../images/sub.gif"alt="[APACHE DOCUMENTATION]"/><h3>Apache HTTP Server Version 2.0</h3></div><h1align="center">Apache Module prefork</h1><tablecellspacing="1"cellpadding="0"bgcolor="#cccccc"><tr><td><tablebgcolor="#ffffff"><tr><tdvalign="top"><spanclass="help">Description:</span></td><td>Implements a non-threaded, pre-forking web server</td></tr><tr><td><ahref="module-dict.html#Status"class="help">Status:</a></td><td>MPM</td></tr><tr><td><ahref="module-dict.html#ModuleIdentifier"class="help">Module Identifier:</a></td><td>mpm_prefork_module</td></tr></table></td></tr></table><h2>Summary</h2>
<p>This Multi-Processing Module (MPM) implements a
non-threaded, pre-forking web server which handles request in a
manner very similar to the default behavior of Apache 1.3 on
Unix.</p>
<p>This Multi-Processing Module (MPM) implements a non-threaded,
pre-forking web server that handles requests in a manner similar
to Apache 1.3. 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.</p>
<p>This MPM is very self-regulating, so it is rarely necessary to
adjust its configuration directives. Most important is that
<ahref="mpm_common.html#maxclients"class="directive"><codeclass="directive">MaxClients</code></a> be big enough to
handle as many simultaneous requests as you expect to receive, but
small enough to assure that there is enough physical RAM for all
processes.</p>
<h2>Directives</h2><ul><li><ahref="#acceptmutex">AcceptMutex</a></li><li><ahref="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li><li><ahref="mpm_common.html#group">Group</a></li><li><ahref="mpm_common.html#listen">Listen</a></li><li><ahref="mpm_common.html#listenbacklog">ListenBacklog</a></li><li><ahref="mpm_common.html#lockfile">LockFile</a></li><li><ahref="mpm_common.html#maxclients">MaxClients</a></li><li><ahref="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li><li><ahref="mpm_common.html#maxspareservers">MaxSpareServers</a></li><li><ahref="#maxspareservers">MaxSpareServers</a></li><li><ahref="mpm_common.html#minspareservers">MinSpareServers</a></li><li><ahref="#minspareservers">MinSpareServers</a></li><li><ahref="mpm_common.html#pidfile">PidFile</a></li><li><ahref="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li><li><ahref="mpm_common.html#sendbuffersize">SendBufferSize</a></li><li><ahref="mpm_common.html#serverlimit">ServerLimit</a></li><li><ahref="mpm_common.html#startservers">StartServers</a></li><li><ahref="mpm_common.html#user">User</a></li></ul><p><strong>See also </strong></p><ul><li><ahref="../bind.html">Setting which addresses and
ports Apache uses</a></li></ul><h2>How it Works</h2>
<p>A single control process is responsible for launching child
processes which listen for connections and serve them when they
arrive. Apache always tries to maintain several <em>spare</em>
@@ -35,16 +46,12 @@
Apache as a less-privileged user. The <ahref="mpm_common.html#user"class="directive"><codeclass="directive">User</code></a> and <ahref="mpm_common.html#group"class="directive"><codeclass="directive">Group</code></a> 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 <ahref="../suexec.html">suexec</a> is used,
these directives also set the privileges which will be inherited
by CGI scripts.</p>
should have as few privileges beyond that as possible.</p>
controls how frequently the server recycles processes by killing
old ones and launching new ones.</p>
<h2>Directives</h2><ul><li><ahref="#acceptmutex">AcceptMutex</a></li><li><ahref="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li><li><ahref="mpm_common.html#listen">Listen</a></li><li><ahref="mpm_common.html#listenbacklog">ListenBacklog</a></li><li><ahref="mpm_common.html#lockfile">LockFile</a></li><li><ahref="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li><li><ahref="mpm_common.html#maxspareservers">MaxSpareServers</a></li><li><ahref="#maxspareservers">MaxSpareServers</a></li><li><ahref="mpm_common.html#minspareservers">MinSpareServers</a></li><li><ahref="#minspareservers">MinSpareServers</a></li><li><ahref="mpm_common.html#pidfile">PidFile</a></li><li><ahref="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li><li><ahref="mpm_common.html#sendbuffersize">SendBufferSize</a></li><li><ahref="mpm_common.html#serverlimit">ServerLimit</a></li><li><ahref="mpm_common.html#startservers">StartServers</a></li><li><ahref="mpm_common.html#user">User</a></li></ul><p><strong>See also </strong></p><ul><li><ahref="../bind.html">Setting which addresses and
ports Apache uses</a></li></ul><hr/><h2><aname="AcceptMutex">AcceptMutex</a><aname="acceptmutex">Directive</a></h2><tablecellpadding="1"cellspacing="0"border="0"bgcolor="#cccccc"><tr><td><tablebgcolor="#ffffff"><tr><tdnowrap="nowrap"><strong>Description: </strong></td><td>Method that Apache uses to serialize multiple children
<hr/><h2><aname="AcceptMutex">AcceptMutex</a><aname="acceptmutex">Directive</a></h2><tablecellpadding="1"cellspacing="0"border="0"bgcolor="#cccccc"><tr><td><tablebgcolor="#ffffff"><tr><tdnowrap="nowrap"><strong>Description: </strong></td><td>Method that Apache uses to serialize multiple children
accepting requests on network sockets</td></tr><tr><tdnowrap="nowrap"><ahref="directive-dict.html#Syntax"class="help">Syntax:</a></td><td>AcceptMutex default|<em>method</em></td></tr><tr><tdnowrap="nowrap"><ahref="directive-dict.html#Default"class="help">Default:</a></td><td><code>AcceptMutex default</code></td></tr><tr><tdnowrap="nowrap"><ahref="directive-dict.html#Context"class="help">Context:</a></td><td>server config</td></tr><tr><tdnowrap="nowrap"><ahref="directive-dict.html#Status"class="help">Status:</a></td><td>MPM</td></tr><tr><tdnowrap="nowrap"><ahref="directive-dict.html#Module"class="help">Module:</a></td><td>prefork</td></tr></table></td></tr></table>
<p>The <codeclass="directive">AcceptMutex</code> directives sets the
method that Apache uses to serialize multiple children accepting
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--><title>worker- Apache HTTP Server</title><linkhref="../style/manual.css"type="text/css"rel="stylesheet"/></head><body><blockquote><divalign="center"><imgsrc="../images/sub.gif"alt="[APACHE DOCUMENTATION]"/><h3>Apache HTTP Server Version 2.0</h3></div><h1align="center">Apache Module worker</h1><tablecellspacing="1"cellpadding="0"bgcolor="#cccccc"><tr><td><tablebgcolor="#ffffff"><tr><tdvalign="top"><spanclass="help">Description:</span></td><td>Multi-Processing Module implementing a hybrid
multi-threaded multi-process web server</td></tr><tr><td><ahref="module-dict.html#Status"class="help">Status:</a></td><td>MPM</td></tr><tr><td><ahref="module-dict.html#ModuleIdentifier"class="help">Module Identifier:</a></td><td>mpm_worker_module</td></tr></table></td></tr></table><h2>Summary</h2>
<p>This Multi-Processing Module (MPM) implements a hybrid
multi-process multi-threaded server. Each process has a fixed
multi-process multi-threaded server. By using threads to serve
requests, it is able to serve a large number of requests with
less system resources than a process-based server. Yet it
retains much of the stability of a process-based server by
keeping multiple processes available, each with many threads.</p>
<p>The most important directives used to control this MPM are
<ahref="mpm_common.html#threadsperchild"class="directive"><codeclass="directive">ThreadsPerChild</code></a> and
<ahref="mpm_common.html#maxclients"class="directive"><codeclass="directive">MaxClients</code></a>. By multiplying
together the value of these directives you define the total number
of simultaneous connections that the server can handle.</p>
<h2>Directives</h2><ul><li><ahref="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li><li><ahref="mpm_common.html#group">Group</a></li><li><ahref="mpm_common.html#listen">Listen</a></li><li><ahref="mpm_common.html#listenbacklog">ListenBacklog</a></li><li><ahref="mpm_common.html#lockfile">LockFile</a></li><li><ahref="mpm_common.html#maxclients">MaxClients</a></li><li><ahref="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li><li><ahref="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li><li><ahref="mpm_common.html#minsparethreads">MinSpareThreads</a></li><li><ahref="mpm_common.html#pidfile">PidFile</a></li><li><ahref="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li><li><ahref="mpm_common.html#sendbuffersize">SendBufferSize</a></li><li><ahref="mpm_common.html#serverlimit">ServerLimit</a></li><li><ahref="mpm_common.html#startservers">StartServers</a></li><li><ahref="mpm_common.html#threadlimit">ThreadLimit</a></li><li><ahref="mpm_common.html#threadsperchild">ThreadsPerChild</a></li><li><ahref="mpm_common.html#user">User</a></li></ul><p><strong>See also </strong></p><ul><li><ahref="../bind.html">Setting which addresses and
ports Apache uses</a></li></ul><h2>How it Works</h2>
<p>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>
processes. Each child process creates a fixed number of threads as
specified in the <ahref="mpm_common.html#threadsperchild"class="directive"><codeclass="directive">ThreadsPerChild</code></a> 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
processes, and forks or kills processes to keep this number within
the boundaries specified by <ahref="mpm_common.html#minsparethreads"class="directive"><codeclass="directive">MinSpareThreads</code></a> and <ahref="mpm_common.html#maxsparethreads"class="directive"><codeclass="directive">MaxSpareThreads</code></a>. 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 <ahref="../suexec.html">suexec</a> is used, these directives also
set the privileges which will be inherited by CGI scripts.</p>
created (<ahref="mpm_common.html#maxclients"class="directive"><codeclass="directive">MaxClients</code></a>) by
the number of threads created in each process (<ahref="mpm_common.html#threadsperchild"class="directive"><codeclass="directive">ThreadsPerChild</code></a>).</p>
<p><code>MaxRequestsPerChild</code> controls how frequently the
server recycles processes by killing old ones and launching new
ones.</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 <ahref="mpm_common.html#user"class="directive"><codeclass="directive">User</code></a> and <ahref="mpm_common.html#group"class="directive"><codeclass="directive">Group</code></a> 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 <ahref="../suexec.html">suexec</a> is used,
these directives also set the privileges which will be inherited
by CGI scripts.</p>
<p>See also: <ahref="../bind.html">Setting which addresses and
ports Apache uses</a>.</p>
<h2>Directives</h2><ul><li><ahref="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li><li><ahref="mpm_common.html#group">Group</a></li><li><ahref="mpm_common.html#listen">Listen</a></li><li><ahref="mpm_common.html#listenbacklog">ListenBacklog</a></li><li><ahref="mpm_common.html#lockfile">LockFile</a></li><li><ahref="mpm_common.html#maxclients">MaxClients</a></li><li><ahref="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li><li><ahref="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li><li><ahref="mpm_common.html#minsparethreads">MinSpareThreads</a></li><li><ahref="mpm_common.html#pidfile">PidFile</a></li><li><ahref="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li><li><ahref="mpm_common.html#sendbuffersize">SendBufferSize</a></li><li><ahref="mpm_common.html#serverlimit">ServerLimit</a></li><li><ahref="mpm_common.html#startservers">StartServers</a></li><li><ahref="mpm_common.html#threadlimit">ThreadLimit</a></li><li><ahref="mpm_common.html#threadsperchild">ThreadsPerChild</a></li><li><ahref="mpm_common.html#user">User</a></li></ul><hr/></blockquote><h3align="center">Apache HTTP Server Version 2.0</h3><ahref="./"><imgsrc="../images/index.gif"alt="Index"/></a><ahref="../"><imgsrc="../images/home.gif"alt="Home"/></a></body></html>
controls how frequently the server recycles processes by killing
old ones and launching new ones.</p>
<hr/></blockquote><h3align="center">Apache HTTP Server Version 2.0</h3><ahref="./"><imgsrc="../images/index.gif"alt="Index"/></a><ahref="../"><imgsrc="../images/home.gif"alt="Home"/></a></body></html>