<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head>
+<meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" />
+<!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
-<title>worker - Apache HTTP Server</title>
+<title>worker - Apache HTTP Server Version 2.5</title>
<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
-<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
+<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" />
+<script src="../style/scripts/prettify.min.js" type="text/javascript">
+</script>
+
<link href="../images/favicon.ico" rel="shortcut icon" /></head>
<body>
<div id="page-header">
-<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/
directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
-<p class="apache">Apache HTTP Server Version 2.3</p>
-<img alt="" src="../images/feather.gif" /></div>
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/
quickreference.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
+<p class="apache">Apache HTTP Server Version 2.5</p>
+<img alt="" src="../images/feather.png" /></div>
<div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
<div id="path">
-<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.
3</a> > <a href="./">Modules</a></div>
+<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.
5</a> > <a href="./">Modules</a></div>
<div id="page-content">
<div id="preamble"><h1>Apache MPM worker</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="../de/mod/worker.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
<a href="../en/mod/worker.html" title="English"> en </a> |
-<a href="../ja/mod/worker.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
+<a href="../fr/mod/worker.html" hreflang="fr" rel="alternate" title="Français"> fr </a> |
+<a href="../ja/mod/worker.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
+<a href="../tr/mod/worker.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
</div>
<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Multi-Processing Module implementing a hybrid
multi-threaded multi-process web server</td></tr>
<p>The most important directives used to control this MPM are
<code class="directive"><a href="../mod/mpm_common.html#threadsperchild">ThreadsPerChild</a></code>, which
controls the number of threads deployed by each child process and
- <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code>, which
+ <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code>, which
controls the maximum total number of threads that may be
launched.</p>
</div>
-<div id="quickview"><h3 class="directives">Directives</h3>
+<div id="quickview"><h3>Topics</h3>
+<ul id="topics">
+<li><img alt="" src="../images/down.gif" /> <a href="#how-it-works">How it Works</a></li>
+</ul><h3 class="directives">Directives</h3>
<ul id="toc">
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#acceptmutex">AcceptMutex</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#enableexceptionhook">EnableExceptionHook</a></li>
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#group">Group</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mod_unixd.html#group">Group</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listen">Listen</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#listenbacklog">ListenBacklog</a></li>
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#lockfile">LockFile</a></li>
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxclients">MaxClients</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxconnectionsperchild">MaxConnectionsPerChild</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxmemfree">MaxMemFree</a></li>
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#maxsparethreads">MaxSpareThreads</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#minsparethreads">MinSpareThreads</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#pidfile">PidFile</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadlimit">ThreadLimit</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadsperchild">ThreadsPerChild</a></li>
<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#threadstacksize">ThreadStackSize</a></li>
-<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#user">User</a></li>
+<li><img alt="" src="../images/right.gif" /> <a href="mod_unixd.html#user">User</a></li>
</ul>
-<h3>Topics</h3>
-<ul id="topics">
-<li><img alt="" src="../images/down.gif" /> <a href="#how-it-works">How it Works</a></li>
-</ul><h3>See also</h3>
+<h3>Bugfix checklist</h3><ul class="seealso"><li><a href="https://www.apache.org/dist/httpd/CHANGES_2.4">httpd changelog</a></li><li><a href="https://bz.apache.org/bugzilla/buglist.cgi?bug_status=__open__&list_id=144532&product=Apache%20httpd-2&query_format=specific&order=changeddate%20DESC%2Cpriority%2Cbug_severity&component=mpm_worker">Known issues</a></li><li><a href="https://bz.apache.org/bugzilla/enter_bug.cgi?product=Apache%20httpd-2&component=mpm_worker">Report a bug</a></li></ul><h3>See also</h3>
<ul class="seealso">
-<li><a href="../bind.html">Setting which addresses and ports Apache
-uses</a></li>
-</ul></div>
+<li><a href="../bind.html">Setting which addresses and ports Apache HTTP Server uses</a></li>
+<li><a href="#comments_section">Comments</a></li></ul></div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<div class="section">
<h2><a name="how-it-works" id="how-it-works">How it Works</a></h2>
- <p>A single control process (the parent) is responsible for launching
+ <p>A single control process (the parent) is responsible for launching
child processes. Each child process creates a fixed number of server
threads as specified in the <code class="directive"><a href="../mod/mpm_common.html#threadsperchild">ThreadsPerChild</a></code> directive, as well
as a listener thread which listens for connections and passes them
to a server thread for processing when they arrive.</p>
- <p>Apache always tries to maintain a pool of <dfn>spare</dfn> or
+ <p>Apache HTTP Server always tries to maintain a pool of <dfn>spare</dfn> 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. The number of processes that will initially launched is
+ served. The number of processes that will initially launch is
set by the <code class="directive"><a href="../mod/mpm_common.html#startservers">StartServers</a></code>
- directive. During operation, Apache assesses the total number
+ directive. During operation, the server 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 class="directive"><a href="../mod/mpm_common.html#minsparethreads">MinSpareThreads</a></code> and <code class="directive"><a href="../mod/mpm_common.html#maxsparethreads">MaxSpareThreads</a></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 (i.e., the maximum total
number of threads in all processes) is determined by the
- <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code> directive.
+ <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code> directive.
The maximum number of active child processes is determined by
- the <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code>
- directive divided by the <code class="directive"><a href="../mod/mpm_common.html# threadsperchild">
+ the <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code>
+ directive divided by the <code class="directive"><a href="../mod/mpm_common.html#threadsperchild">
ThreadsPerChild</a></code> directive.</p>
<p>Two directives set hard limits on the number of active child
processes and the number of server threads in a child process,
- and can only be changed by fully stopping the server and then
- starting it again. <code class="directive"><a href="../mod/mpm_common.html#serverlimit ">ServerLimit
- </a></code> is a hard limit on the number of active child
- processes, and must be greater than or equal to the
- <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code>
- directive divided by the <code class="directive"><a href="../mod/mpm_common.html# threadsperchild">
- ThreadsPerChild</a></code> directive.
+ and can only be changed by fully stopping the server and then
+ starting it again. <code class="directive"><a href="../mod/mpm_common.html#serverlimit">ServerLimit
+ </a></code> is a hard limit on the number of active child
+ processes, and must be greater than or equal to the
+ <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code>
+ directive divided by the <code class="directive"><a href="../mod/mpm_common.html#threadsperchild">
+ ThreadsPerChild</a></code> directive.
<code class="directive"><a href="../mod/mpm_common.html#threadlimit">ThreadLimit</a></code> is a hard
limit of the number of server threads, and must be greater than
- or equal to the <code class="directive"><a href="../mod/mpm_common.html#threadsperchild">ThreadsPerChild</a></code> directive. If
- non-default values are specified for these directives, they
- should appear before other <code class="module"><a href="../mod/worker.html">worker</a></code> directives.</p>
+ or equal to the <code class="directive"><a href="../mod/mpm_common.html#threadsperchild">ThreadsPerChild</a></code> directive.</p>
- <p>In addition to the set of active child processes, there may
+ <p>In addition to the set of active child processes, there may
be additional child processes which are terminating, but where at
least one server thread is still handling an existing client
- connection. Up to <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code> terminating processes
- may be present, though the actual number can be expected to be
- much smaller. This behavior can be avoided by disabling the
+ connection. Up to <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code> terminating processes
+ may be present, though the actual number can be expected to be
+ much smaller. This behavior can be avoided by disabling the
termination of individual child processes, which is achieved using
the following:</p>
<ul>
- <li>set the value of <code class="directive"><a href="../mod/mpm_common.html# maxrequestsperchild">
- MaxRequestsPerChild</a></code> to zero</li>
+ <li>set the value of <code class="directive"><a href="../mod/mpm_common.html#maxconnectionsperchild">
+ MaxConnectionsPerChild</a></code> to zero</li>
- <li>set the value of <code class="directive"><a href="../mod/mpm_common.html# maxsparethreads">
+ <li>set the value of <code class="directive"><a href="../mod/mpm_common.html#maxsparethreads">
MaxSpareThreads</a></code> to the same value as
- <code class="directive"><a href="../mod/mpm_common.html#maxclients">MaxClients</a></code></li>
+ <code class="directive"><a href="../mod/mpm_common.html#maxrequestworkers">MaxRequestWorkers</a></code></li>
</ul>
<p>A typical configuration of the process-thread controls in
the <code class="module"><a href="../mod/worker.html">worker</a></code> MPM could look as follows:</p>
- <div class="example"><p><code>
- ServerLimit 16<br />
- StartServers 2<br />
- MaxClients 150<br />
- MinSpareThreads 25<br />
- MaxSpareThreads 75<br />
- ThreadsPerChild 25
- </code></p></div>
+ <pre class="prettyprint lang-config">ServerLimit 16
+StartServers 2
+MaxRequestWorkers 150
+MinSpareThreads 25
+MaxSpareThreads 75
+ThreadsPerChild 25</pre>
+
<p>While the parent process is usually started as <code>root</code>
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 class="directive"><a href="../mod/mpm_common.html#user">User</a></code> and <code class="directive"><a href="../mod/mpm_common.html#group">Group</a></code> directives are used to set
- the privileges of the Apache child processes. The child processes
+ are launched by the server as a less-privileged user. The <code class="directive"><a href="../mod/mod_unixd.html#user">User</a></code> and <code class="directive"><a href="../mod/mod_unixd.html#group">Group</a></code> directives are used to set
+ the privileges of the Apache HTTP Server 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 <code class="program"><a href="../programs/suexec.html">suexec</a></code> is used,
these directives also set the privileges which will be inherited
by CGI scripts.</p>
- <p><code class="directive"><a href="../mod/mpm_common.html#maxrequestsperchild">MaxRequestsPerChild</a></code>
+ <p><code class="directive"><a href="../mod/mpm_common.html#maxconnectionsperchild">MaxConnectionsPerChild</a></code>
controls how frequently the server recycles processes by killing
old ones and launching new ones.</p>
+
+ <p>This MPM uses the <code>mpm-accept</code> mutex to serialize
+ access to incoming connections when subject to the thundering herd
+ problem (generally, when there are multiple listening sockets).
+ The implementation aspects of this mutex can be configured with the
+ <code class="directive"><a href="../mod/core.html#mutex">Mutex</a></code> directive. The <a href="../misc/perf-tuning.html">performance hints</a>
+ documentation has additional information about this mutex.</p>
</div>
</div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="../de/mod/worker.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> |
<a href="../en/mod/worker.html" title="English"> en </a> |
-<a href="../ja/mod/worker.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
-</div><div id="footer">
-<p class="apache">Copyright 2006 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
-<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
+<a href="../fr/mod/worker.html" hreflang="fr" rel="alternate" title="Français"> fr </a> |
+<a href="../ja/mod/worker.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> |
+<a href="../tr/mod/worker.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p>
+</div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed again by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Freenode, or sent to our <a href="http://httpd.apache.org/lists.html">mailing lists</a>.</div>
+<script type="text/javascript"><!--//--><![CDATA[//><!--
+var comments_shortname = 'httpd';
+var comments_identifier = 'http://httpd.apache.org/docs/trunk/mod/worker.html';
+(function(w, d) {
+ if (w.location.hostname.toLowerCase() == "httpd.apache.org") {
+ d.write('<div id="comments_thread"><\/div>');
+ var s = d.createElement('script');
+ s.type = 'text/javascript';
+ s.async = true;
+ s.src = 'https://comments.apache.org/show_comments.lua?site=' + comments_shortname + '&page=' + comments_identifier;
+ (d.getElementsByTagName('head')[0] || d.getElementsByTagName('body')[0]).appendChild(s);
+ }
+ else {
+ d.write('<div id="comments_thread">Comments are disabled for this page at the moment.<\/div>');
+ }
+})(window, document);
+//--><!]]></script></div><div id="footer">
+<p class="apache">Copyright 2017 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/quickreference.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div><script type="text/javascript"><!--//--><![CDATA[//><!--
+if (typeof(prettyPrint) !== 'undefined') {
+ prettyPrint();
+}
+//--><!]]></script>
</body></html>
\ No newline at end of file
projects / apache / blobdiff