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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:01:30 +0000 |
| commit | 6beeb1b708550be0d4a53b272283e17e5e35fe17 (patch) | |
| tree | 1ce8673d4aaa948e5554000101f46536a1e4cc29 /docs/manual/mod/worker.html.en | |
| parent | Initial commit. (diff) | |
| download | apache2-3d46059c28a1d66e6e1aeb209491f1324c913a25.tar.xz apache2-3d46059c28a1d66e6e1aeb209491f1324c913a25.zip | |
Adding upstream version 2.4.57.upstream/2.4.57
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/manual/mod/worker.html.en')
| -rw-r--r-- | docs/manual/mod/worker.html.en | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/docs/manual/mod/worker.html.en b/docs/manual/mod/worker.html.en new file mode 100644 index 0000000..3472a3f --- /dev/null +++ b/docs/manual/mod/worker.html.en @@ -0,0 +1,208 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!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> +<meta content="text/html; charset=UTF-8" http-equiv="Content-Type" /> +<!-- + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + This file is generated from xml source: DO NOT EDIT + XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX + --> +<title>worker - Apache HTTP Server Version 2.4</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 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="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 2.4</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 2.4</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="../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> +<tr><th><a href="module-dict.html#Status">Status:</a></th><td>MPM</td></tr> +<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>mpm_worker_module</td></tr> +<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>worker.c</td></tr></table> +<h3>Summary</h3> + + <p>This Multi-Processing Module (MPM) implements a hybrid + multi-process multi-threaded server. By using threads to serve + requests, it is able to serve a large number of requests with + fewer system resources than a process-based server. However, 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 + <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#maxrequestworkers">MaxRequestWorkers</a></code>, which + controls the maximum total number of threads that may be + launched.</p> +</div> +<div id="quickview"><a href="https://www.apache.org/foundation/contributing.html" class="badge"><img src="https://www.apache.org/images/SupportApache-small.png" alt="Support Apache!" /></a><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#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="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#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#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#receivebuffersize">ReceiveBufferSize</a></li> +<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#scoreboardfile">ScoreBoardFile</a></li> +<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#sendbuffersize">SendBufferSize</a></li> +<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#serverlimit">ServerLimit</a></li> +<li><img alt="" src="../images/right.gif" /> <a href="mpm_common.html#startservers">StartServers</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="mod_unixd.html#user">User</a></li> +</ul> +<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 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 + 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 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 launch is + set by the <code class="directive"><a href="../mod/mpm_common.html#startservers">StartServers</a></code> + 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#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#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#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.</p> + + <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#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#maxconnectionsperchild"> + MaxConnectionsPerChild</a></code> to zero</li> + + <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#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> + + <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 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#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="../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 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 Libera.chat, or sent to our <a href="https://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/2.4/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 2023 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="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>
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