diff options
| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 06:33:50 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 06:33:50 +0000 |
| commit | fe39ffb8b90ae4e002ed73fe98617cd590abb467 (patch) | |
| tree | b80e5956907d8aeaaffe4e4f0c068c0e6157ce8b /docs/manual/stopping.html.en | |
| parent | Initial commit. (diff) | |
| download | apache2-fe39ffb8b90ae4e002ed73fe98617cd590abb467.tar.xz apache2-fe39ffb8b90ae4e002ed73fe98617cd590abb467.zip | |
Adding upstream version 2.4.56.upstream/2.4.56
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/manual/stopping.html.en')
| -rw-r--r-- | docs/manual/stopping.html.en | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/docs/manual/stopping.html.en b/docs/manual/stopping.html.en new file mode 100644 index 0000000..79f3d2d --- /dev/null +++ b/docs/manual/stopping.html.en @@ -0,0 +1,264 @@ +<?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>Stopping and Restarting Apache HTTP Server - 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 id="manual-page"><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></div><div id="page-content"><div id="preamble"><h1>Stopping and Restarting Apache HTTP Server</h1> +<div class="toplang"> +<p><span>Available Languages: </span><a href="./de/stopping.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | +<a href="./en/stopping.html" title="English"> en </a> | +<a href="./es/stopping.html" hreflang="es" rel="alternate" title="Español"> es </a> | +<a href="./fr/stopping.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | +<a href="./ja/stopping.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | +<a href="./ko/stopping.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | +<a href="./tr/stopping.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> +</div> + + <p>This document covers stopping and restarting Apache HTTP Server on + Unix-like systems. Windows NT, 2000 and XP users should see + <a href="platform/windows.html#winsvc">Running httpd as a + Service</a> and Windows 9x and ME users should see <a href="platform/windows.html#wincons">Running httpd as a + Console Application</a> for information on how to control + httpd on those platforms.</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><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#introduction">Introduction</a></li> +<li><img alt="" src="./images/down.gif" /> <a href="#term">Stop Now</a></li> +<li><img alt="" src="./images/down.gif" /> <a href="#graceful">Graceful Restart</a></li> +<li><img alt="" src="./images/down.gif" /> <a href="#hup">Restart Now</a></li> +<li><img alt="" src="./images/down.gif" /> <a href="#gracefulstop">Graceful Stop</a></li> +</ul><h3>See also</h3><ul class="seealso"><li><code class="program"><a href="./programs/httpd.html">httpd</a></code></li><li><code class="program"><a href="./programs/apachectl.html">apachectl</a></code></li><li><a href="invoking.html">Starting</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="introduction" id="introduction">Introduction</a></h2> + + <p>In order to stop or restart the Apache HTTP Server, you must send a signal to + the running <code class="program"><a href="./programs/httpd.html">httpd</a></code> processes. There are two ways to + send the signals. First, you can use the unix <code>kill</code> + command to directly send signals to the processes. You will + notice many <code class="program"><a href="./programs/httpd.html">httpd</a></code> executables running on your system, + but you should not send signals to any of them except the parent, + whose pid is in the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code>. That is to say you + shouldn't ever need to send signals to any process except the + parent. There are four signals that you can send the parent: + <code><a href="#term">TERM</a></code>, + <code><a href="#graceful">USR1</a></code>, + <code><a href="#hup">HUP</a></code>, and + <code><a href="#gracefulstop">WINCH</a></code>, which + will be described in a moment.</p> + + <p>To send a signal to the parent you should issue a command + such as:</p> + +<div class="example"><p><code>kill -TERM `cat /usr/local/apache2/logs/httpd.pid`</code></p></div> + + <p>The second method of signaling the <code class="program"><a href="./programs/httpd.html">httpd</a></code> processes + is to use the <code>-k</code> command line options: <code>stop</code>, + <code>restart</code>, <code>graceful</code> and <code>graceful-stop</code>, + as described below. These are arguments to the <code class="program"><a href="./programs/httpd.html">httpd</a></code> binary, but we recommend that + you send them using the <code class="program"><a href="./programs/apachectl.html">apachectl</a></code> control script, which + will pass them through to <code class="program"><a href="./programs/httpd.html">httpd</a></code>.</p> + + <p>After you have signaled <code class="program"><a href="./programs/httpd.html">httpd</a></code>, you can read about + its progress by issuing:</p> + +<div class="example"><p><code>tail -f /usr/local/apache2/logs/error_log</code></p></div> + + <p>Modify those examples to match your <code class="directive"><a href="./mod/core.html#serverroot">ServerRoot</a></code> and <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> settings.</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> +<div class="section"> +<h2><a name="term" id="term">Stop Now</a></h2> + +<dl><dt>Signal: TERM</dt> +<dd><code>apachectl -k stop</code></dd> +</dl> + + <p>Sending the <code>TERM</code> or <code>stop</code> signal to + the parent causes it to immediately attempt to kill off all of its + children. It may take it several seconds to complete killing off + its children. Then the parent itself exits. Any requests in + progress are terminated, and no further requests are served.</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> +<div class="section"> +<h2><a name="graceful" id="graceful">Graceful Restart</a></h2> + +<dl><dt>Signal: USR1</dt> +<dd><code>apachectl -k graceful</code></dd> +</dl> + + <p>The <code>USR1</code> or <code>graceful</code> signal causes + the parent process to <em>advise</em> the children to exit after + their current request (or to exit immediately if they're not + serving anything). The parent re-reads its configuration files and + re-opens its log files. As each child dies off the parent replaces + it with a child from the new <em>generation</em> of the + configuration, which begins serving new requests immediately.</p> + + <p>This code is designed to always respect the process control + directive of the MPMs, so the number of processes and threads + available to serve clients will be maintained at the appropriate + values throughout the restart process. Furthermore, it respects + <code class="directive"><a href="./mod/mpm_common.html#startservers">StartServers</a></code> in the + following manner: if after one second at least <code class="directive"><a href="./mod/mpm_common.html#startservers">StartServers</a></code> new children have not + been created, then create enough to pick up the slack. Hence the + code tries to maintain both the number of children appropriate for + the current load on the server, and respect your wishes with the + <code class="directive"><a href="./mod/mpm_common.html#startservers">StartServers</a></code> + parameter.</p> + + <p>Users of <code class="module"><a href="./mod/mod_status.html">mod_status</a></code> + will notice that the server statistics are <strong>not</strong> + set to zero when a <code>USR1</code> is sent. The code was + written to both minimize the time in which the server is unable + to serve new requests (they will be queued up by the operating + system, so they're not lost in any event) and to respect your + tuning parameters. In order to do this it has to keep the + <em>scoreboard</em> used to keep track of all children across + generations.</p> + + <p>The status module will also use a <code>G</code> to indicate + those children which are still serving requests started before + the graceful restart was given.</p> + + <p>At present there is no way for a log rotation script using + <code>USR1</code> to know for certain that all children writing + the pre-restart log have finished. We suggest that you use a + suitable delay after sending the <code>USR1</code> signal + before you do anything with the old log. For example if most of + your hits take less than 10 minutes to complete for users on + low bandwidth links then you could wait 15 minutes before doing + anything with the old log.</p> + + <div class="note"> + <p>When you issue a restart, a syntax check is first run, to + ensure that there are no errors in the configuration files. + If your configuration file has errors in it, you will get an + error message about that syntax error, and the server will refuse to + restart. This avoids the situation where the server halts and then + cannot restart, leaving you with a non-functioning server.</p> + + <p>This still will not + guarantee that the server will restart correctly. To check the + semantics of the configuration files as well as the syntax, you + can try starting <code class="program"><a href="./programs/httpd.html">httpd</a></code> as a non-root user. If there + are no errors it will attempt to open its sockets and logs and fail + because it's not root (or because the currently running + <code class="program"><a href="./programs/httpd.html">httpd</a></code> already has those ports bound). If it fails + for any other reason then it's probably a config file error and the error + should be fixed before issuing the graceful restart.</p></div> +</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> +<div class="section"> +<h2><a name="hup" id="hup">Restart Now</a></h2> + +<dl><dt>Signal: HUP</dt> +<dd><code>apachectl -k restart</code></dd> +</dl> + + <p>Sending the <code>HUP</code> or <code>restart</code> signal to + the parent causes it to kill off its children like in + <code>TERM</code>, but the parent doesn't exit. It re-reads its + configuration files, and re-opens any log files. Then it spawns a + new set of children and continues serving hits.</p> + + <p>Users of <code class="module"><a href="./mod/mod_status.html">mod_status</a></code> + will notice that the server statistics are set to zero when a + <code>HUP</code> is sent.</p> + +<div class="note">As with a graceful restart, a syntax check is run before the +restart is attempted. If your configuration file has errors in it, the +restart will not be attempted, and you will receive notification of the +syntax error(s).</div> +</div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> +<div class="section"> +<h2><a name="gracefulstop" id="gracefulstop">Graceful Stop</a></h2> + +<dl><dt>Signal: WINCH</dt> +<dd><code>apachectl -k graceful-stop</code></dd> +</dl> + + <p>The <code>WINCH</code> or <code>graceful-stop</code> signal causes + the parent process to <em>advise</em> the children to exit after + their current request (or to exit immediately if they're not + serving anything). The parent will then remove its <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> and cease listening on + all ports. The parent will continue to run, and monitor children + which are handling requests. Once all children have finalised + and exited or the timeout specified by the <code class="directive"><a href="./mod/mpm_common.html#gracefulshutdowntimeout">GracefulShutdownTimeout</a></code> has been + reached, the parent will also exit. If the timeout is reached, + any remaining children will be sent the <code>TERM</code> signal + to force them to exit.</p> + + <p>A <code>TERM</code> signal will immediately terminate the + parent process and all children when in the "graceful" state. However + as the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> will + have been removed, you will not be able to use + <code>apachectl</code> or <code>httpd</code> to send this signal.</p> + + <div class="note"><p>The <code>graceful-stop</code> signal allows you to run multiple + identically configured instances of <code class="program"><a href="./programs/httpd.html">httpd</a></code> at the + same time. This is a powerful feature when performing graceful + upgrades of httpd, however it can also cause deadlocks and race + conditions with some configurations.</p> + + <p>Care has been taken to ensure that on-disk files such as lock files + (<code class="directive"><a href="./mod/core.html#mutex">Mutex</a></code>) and Unix socket files + (<code class="directive"><a href="./mod/mod_cgid.html#scriptsock">ScriptSock</a></code>) contain the server + PID, and should coexist without problem. However, if a configuration + directive, third-party module or persistent CGI utilises any other on-disk + lock or state files, care should be taken to ensure that multiple running + instances of <code class="program"><a href="./programs/httpd.html">httpd</a></code> do not clobber each other's files.</p> + + <p>You should also be wary of other potential race conditions, such as + using <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code> style piped logging. Multiple running + instances of <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code> attempting to rotate the same + logfiles at the same time may destroy each other's logfiles.</p></div> +</div></div> +<div class="bottomlang"> +<p><span>Available Languages: </span><a href="./de/stopping.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | +<a href="./en/stopping.html" title="English"> en </a> | +<a href="./es/stopping.html" hreflang="es" rel="alternate" title="Español"> es </a> | +<a href="./fr/stopping.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | +<a href="./ja/stopping.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | +<a href="./ko/stopping.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | +<a href="./tr/stopping.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/stopping.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>
\ No newline at end of file |