github.com/krum110487/go-htaccess@v0.0.0-20240316004156-60641c8e7598/tests/data/apache_2_2_34/manual/stopping.html.en (about) 1 <?xml version="1.0" encoding="ISO-8859-1"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3 <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head> 4 <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" /> 5 <!-- 6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 This file is generated from xml source: DO NOT EDIT 8 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 9 --> 10 <title>Stopping and Restarting - Apache HTTP Server Version 2.2</title> 11 <link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> 12 <link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> 13 <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" /> 14 <script src="./style/scripts/prettify.min.js" type="text/javascript"> 15 </script> 16 17 <link href="./images/favicon.ico" rel="shortcut icon" /><link href="http://httpd.apache.org/docs/current/stopping.html" rel="canonical" /></head> 18 <body id="manual-page"><div id="page-header"> 19 <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> 20 <p class="apache">Apache HTTP Server Version 2.2</p> 21 <img alt="" src="./images/feather.gif" /></div> 22 <div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div> 23 <div id="path"> 24 <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 2.2</a></div><div id="page-content"><div class="retired"><h4>Please note</h4> 25 <p> This document refers to a legacy release (<strong>2.2</strong>) of Apache httpd. The active release (<strong>2.4</strong>) is documented <a href="http://httpd.apache.org/docs/current">here</a>. If you have not already upgraded, please follow <a href="http://httpd.apache.org/docs/current/upgrading.html">this link</a> for more information.</p> 26 <p>You may follow <a href="http://httpd.apache.org/docs/current/stopping.html">this link</a> to go to the current version of this document.</p></div><div id="preamble"><h1>Stopping and Restarting</h1> 27 <div class="toplang"> 28 <p><span>Available Languages: </span><a href="./de/stopping.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | 29 <a href="./en/stopping.html" title="English"> en </a> | 30 <a href="./es/stopping.html" hreflang="es" rel="alternate" title="Español"> es </a> | 31 <a href="./fr/stopping.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | 32 <a href="./ja/stopping.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 33 <a href="./ko/stopping.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | 34 <a href="./tr/stopping.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> 35 </div> 36 37 <p>This document covers stopping and restarting Apache on 38 Unix-like systems. Windows NT, 2000 and XP users should see 39 <a href="platform/windows.html#winsvc">Running Apache as a 40 Service</a> and Windows 9x and ME users should see <a href="platform/windows.html#wincons">Running Apache as a 41 Console Application</a> for information on how to control 42 Apache on those platforms.</p> 43 </div> 44 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#introduction">Introduction</a></li> 45 <li><img alt="" src="./images/down.gif" /> <a href="#term">Stop Now</a></li> 46 <li><img alt="" src="./images/down.gif" /> <a href="#graceful">Graceful Restart</a></li> 47 <li><img alt="" src="./images/down.gif" /> <a href="#hup">Restart Now</a></li> 48 <li><img alt="" src="./images/down.gif" /> <a href="#gracefulstop">Graceful Stop</a></li> 49 </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></ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> 50 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> 51 <div class="section"> 52 <h2><a name="introduction" id="introduction">Introduction</a></h2> 53 54 <p>In order to stop or restart Apache, you must send a signal to 55 the running <code class="program"><a href="./programs/httpd.html">httpd</a></code> processes. There are two ways to 56 send the signals. First, you can use the unix <code>kill</code> 57 command to directly send signals to the processes. You will 58 notice many <code class="program"><a href="./programs/httpd.html">httpd</a></code> executables running on your system, 59 but you should not send signals to any of them except the parent, 60 whose pid is in the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code>. That is to say you 61 shouldn't ever need to send signals to any process except the 62 parent. There are four signals that you can send the parent: 63 <code><a href="#term">TERM</a></code>, 64 <code><a href="#graceful">USR1</a></code>, 65 <code><a href="#hup">HUP</a></code>, and 66 <code><a href="#gracefulstop">WINCH</a></code>, which 67 will be described in a moment.</p> 68 69 <p>To send a signal to the parent you should issue a command 70 such as:</p> 71 72 <div class="example"><p><code>kill -TERM `cat /usr/local/apache2/logs/httpd.pid`</code></p></div> 73 74 <p>The second method of signaling the <code class="program"><a href="./programs/httpd.html">httpd</a></code> processes 75 is to use the <code>-k</code> command line options: <code>stop</code>, 76 <code>restart</code>, <code>graceful</code> and <code>graceful-stop</code>, 77 as described below. These are arguments to the <code class="program"><a href="./programs/httpd.html">httpd</a></code> binary, but we recommend that 78 you send them using the <code class="program"><a href="./programs/apachectl.html">apachectl</a></code> control script, which 79 will pass them through to <code class="program"><a href="./programs/httpd.html">httpd</a></code>.</p> 80 81 <p>After you have signaled <code class="program"><a href="./programs/httpd.html">httpd</a></code>, you can read about 82 its progress by issuing:</p> 83 84 <div class="example"><p><code>tail -f /usr/local/apache2/logs/error_log</code></p></div> 85 86 <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> 87 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> 88 <div class="section"> 89 <h2><a name="term" id="term">Stop Now</a></h2> 90 91 <dl><dt>Signal: TERM</dt> 92 <dd><code>apachectl -k stop</code></dd> 93 </dl> 94 95 <p>Sending the <code>TERM</code> or <code>stop</code> signal to 96 the parent causes it to immediately attempt to kill off all of its 97 children. It may take it several seconds to complete killing off 98 its children. Then the parent itself exits. Any requests in 99 progress are terminated, and no further requests are served.</p> 100 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> 101 <div class="section"> 102 <h2><a name="graceful" id="graceful">Graceful Restart</a></h2> 103 104 <dl><dt>Signal: USR1</dt> 105 <dd><code>apachectl -k graceful</code></dd> 106 </dl> 107 108 <p>The <code>USR1</code> or <code>graceful</code> signal causes 109 the parent process to <em>advise</em> the children to exit after 110 their current request (or to exit immediately if they're not 111 serving anything). The parent re-reads its configuration files and 112 re-opens its log files. As each child dies off the parent replaces 113 it with a child from the new <em>generation</em> of the 114 configuration, which begins serving new requests immediately.</p> 115 116 <p>This code is designed to always respect the process control 117 directive of the MPMs, so the number of processes and threads 118 available to serve clients will be maintained at the appropriate 119 values throughout the restart process. Furthermore, it respects 120 <code class="directive"><a href="./mod/mpm_common.html#startservers">StartServers</a></code> in the 121 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 122 been created, then create enough to pick up the slack. Hence the 123 code tries to maintain both the number of children appropriate for 124 the current load on the server, and respect your wishes with the 125 <code class="directive"><a href="./mod/mpm_common.html#startservers">StartServers</a></code> 126 parameter.</p> 127 128 <p>Users of <code class="module"><a href="./mod/mod_status.html">mod_status</a></code> 129 will notice that the server statistics are <strong>not</strong> 130 set to zero when a <code>USR1</code> is sent. The code was 131 written to both minimize the time in which the server is unable 132 to serve new requests (they will be queued up by the operating 133 system, so they're not lost in any event) and to respect your 134 tuning parameters. In order to do this it has to keep the 135 <em>scoreboard</em> used to keep track of all children across 136 generations.</p> 137 138 <p>The status module will also use a <code>G</code> to indicate 139 those children which are still serving requests started before 140 the graceful restart was given.</p> 141 142 <p>At present there is no way for a log rotation script using 143 <code>USR1</code> to know for certain that all children writing 144 the pre-restart log have finished. We suggest that you use a 145 suitable delay after sending the <code>USR1</code> signal 146 before you do anything with the old log. For example if most of 147 your hits take less than 10 minutes to complete for users on 148 low bandwidth links then you could wait 15 minutes before doing 149 anything with the old log.</p> 150 151 <div class="note">If your configuration file has errors 152 in it when you issue a restart then your parent will not 153 restart, it will exit with an error. In the case of graceful 154 restarts it will also leave children running when it exits. 155 (These are the children which are "gracefully exiting" by 156 handling their last request.) This will cause problems if you 157 attempt to restart the server -- it will not be able to bind to 158 its listening ports. Before doing a restart, you can check the 159 syntax of the configuration files with the <code>-t</code> 160 command line argument (see <code class="program"><a href="./programs/httpd.html">httpd</a></code>). This still will not 161 guarantee that the server will restart correctly. To check the 162 semantics of the configuration files as well as the syntax, you 163 can try starting <code class="program"><a href="./programs/httpd.html">httpd</a></code> as a non-root user. If there 164 are no errors it will attempt to open its sockets and logs and fail 165 because it's not root (or because the currently running 166 <code class="program"><a href="./programs/httpd.html">httpd</a></code> already has those ports bound). If it fails 167 for any other reason then it's probably a config file error and the error 168 should be fixed before issuing the graceful restart.</div> 169 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> 170 <div class="section"> 171 <h2><a name="hup" id="hup">Restart Now</a></h2> 172 173 <dl><dt>Signal: HUP</dt> 174 <dd><code>apachectl -k restart</code></dd> 175 </dl> 176 177 <p>Sending the <code>HUP</code> or <code>restart</code> signal to 178 the parent causes it to kill off its children like in 179 <code>TERM</code>, but the parent doesn't exit. It re-reads its 180 configuration files, and re-opens any log files. Then it spawns a 181 new set of children and continues serving hits.</p> 182 183 <p>Users of <code class="module"><a href="./mod/mod_status.html">mod_status</a></code> 184 will notice that the server statistics are set to zero when a 185 <code>HUP</code> is sent.</p> 186 187 <div class="note">If your configuration file has errors in it when you issue a 188 restart then your parent will not restart, it will exit with an 189 error. See above for a method of avoiding this.</div> 190 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div> 191 <div class="section"> 192 <h2><a name="gracefulstop" id="gracefulstop">Graceful Stop</a></h2> 193 194 <dl><dt>Signal: WINCH</dt> 195 <dd><code>apachectl -k graceful-stop</code></dd> 196 </dl> 197 198 <p>The <code>WINCH</code> or <code>graceful-stop</code> signal causes 199 the parent process to <em>advise</em> the children to exit after 200 their current request (or to exit immediately if they're not 201 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 202 all ports. The parent will continue to run, and monitor children 203 which are handling requests. Once all children have finalised 204 and exited or the timeout specified by the <code class="directive"><a href="./mod/mpm_common.html#gracefulshutdowntimeout">GracefulShutdownTimeout</a></code> has been 205 reached, the parent will also exit. If the timeout is reached, 206 any remaining children will be sent the <code>TERM</code> signal 207 to force them to exit.</p> 208 209 <p>A <code>TERM</code> signal will immediately terminate the 210 parent process and all children when in the "graceful" state. However 211 as the <code class="directive"><a href="./mod/mpm_common.html#pidfile">PidFile</a></code> will 212 have been removed, you will not be able to use 213 <code>apachectl</code> or <code>httpd</code> to send this signal.</p> 214 215 <div class="note"><p>The <code>graceful-stop</code> signal allows you to run multiple 216 identically configured instances of <code class="program"><a href="./programs/httpd.html">httpd</a></code> at the 217 same time. This is a powerful feature when performing graceful 218 upgrades of Apache, however it can also cause deadlocks and race 219 conditions with some configurations.</p> 220 221 <p>Care has been taken to ensure that on-disk files 222 such as the <code class="directive"><a href="./mod/mpm_common.html#lockfile">Lockfile</a></code> and <code class="directive"><a href="./mod/mod_cgid.html#scriptsock">ScriptSock</a></code> files contain the server 223 PID, and should coexist without problem. However, if a configuration 224 directive, third-party module or persistent CGI utilises any other on-disk 225 lock or state files, care should be taken to ensure that multiple running 226 instances of <code class="program"><a href="./programs/httpd.html">httpd</a></code> do not clobber each other's files.</p> 227 228 <p>You should also be wary of other potential race conditions, such as 229 using <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code> style piped logging. Multiple running 230 instances of <code class="program"><a href="./programs/rotatelogs.html">rotatelogs</a></code> attempting to rotate the same 231 logfiles at the same time may destroy each other's logfiles.</p></div> 232 </div></div> 233 <div class="bottomlang"> 234 <p><span>Available Languages: </span><a href="./de/stopping.html" hreflang="de" rel="alternate" title="Deutsch"> de </a> | 235 <a href="./en/stopping.html" title="English"> en </a> | 236 <a href="./es/stopping.html" hreflang="es" rel="alternate" title="Español"> es </a> | 237 <a href="./fr/stopping.html" hreflang="fr" rel="alternate" title="Français"> fr </a> | 238 <a href="./ja/stopping.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 239 <a href="./ko/stopping.html" hreflang="ko" rel="alternate" title="Korean"> ko </a> | 240 <a href="./tr/stopping.html" hreflang="tr" rel="alternate" title="Türkçe"> tr </a></p> 241 </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. 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