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Posted to cvs@httpd.apache.org by sl...@locus.apache.org on 2000/12/21 06:38:30 UTC
cvs commit: httpd-2.0/docs/manual stopping.html
slive 00/12/20 21:38:29
Modified: docs/manual stopping.html
Log:
A few small changes to bring this up to 2.0.
This doc could use a major rewrite.
Revision Changes Path
1.18 +67 -59 httpd-2.0/docs/manual/stopping.html
Index: stopping.html
===================================================================
RCS file: /home/cvs/httpd-2.0/docs/manual/stopping.html,v
retrieving revision 1.17
retrieving revision 1.18
diff -u -d -b -u -r1.17 -r1.18
--- stopping.html 2000/11/23 03:59:22 1.17
+++ stopping.html 2000/12/21 05:38:28 1.18
@@ -1,7 +1,7 @@
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
-<TITLE>Stopping and Restarting Apache</TITLE>
+<TITLE>Stopping and Restarting the Server</TITLE>
</HEAD>
<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
@@ -13,11 +13,12 @@
ALINK="#FF0000"
>
<!--#include virtual="header.html" -->
-<H1 ALIGN="CENTER">Stopping and Restarting Apache</H1>
+<H1 ALIGN="CENTER">Stopping and Restarting the Server</H1>
-<P>This document covers stopping and restarting Apache on Unix
-only. Windows users should see <A HREF="platform/windows.html#signal">Signalling
-Apache when running</A>.</P>
+<P>This document covers stopping and restarting Apache on Unix-like
+systems. Windows users should see <A
+HREF="platform/windows.html#signal">Signalling Apache when
+running</A>.</P>
<P>You will notice many <CODE>httpd</CODE> executables running on your system,
but you should not send signals to any of them except the parent, whose
@@ -42,59 +43,45 @@
<A HREF="mod/core.html#serverroot">ServerRoot</A> and
<A HREF="mod/core.html#pidfile">PidFile</A> settings.
-<P>As of Apache 1.3 we provide a script <CODE>src/support/apachectl</CODE>
-which can be used to start, stop, and restart Apache. It may need a
-little customization for your system, see the comments at the top of
-the script.
+<p>A shell script called <code>apachectl</code> is provided
+which automates the processing of signalling Apache.
+For details about this script, see the documentation
+on <a href="invoking.html">starting Apache</a>.</p>
-<H3>TERM Signal: stop now</H3>
+<H3>Stop Now</h3>
+
+<p><strong>Signal:</strong> TERM<br>
+<code>apachectl stop</code></p>
<P>Sending the <CODE>TERM</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.
-
-<H3>HUP Signal: restart now</H3>
-
-<P>Sending the <CODE>HUP</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>Users of the
-<A HREF="mod/mod_status.html">status module</A>
-will notice that the server statistics are
-set to zero when a <CODE>HUP</CODE> is sent.
-
-<P><STRONG>Note:</STRONG> If your configuration file has errors in it when
-you issue a
-restart then your parent will not restart, it will exit with an error.
-See below for a method of avoiding this.
-
-<H3>USR1 Signal: graceful restart</H3>
+<H3>Graceful Restart</H3>
-<P><STRONG>Note:</STRONG> prior to release 1.2b9 this code is quite unstable
-and shouldn't be used at all.
+<p><strong>Signal:</strong> WINCH<br>
+<code>apachectl graceful</code></p>
-<P>The <CODE>USR1</CODE> signal causes the parent process to <EM>advise</EM>
+<P>The <CODE>WINCH</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.
+configuration, which begins serving new requests immediately.</p>
-<P>This code is designed to always respect the
-<A HREF="mod/core.html#maxclients">MaxClients</A>,
-<A HREF="mod/core.html#minspareservers">MinSpareServers</A>,
-and <A HREF="mod/core.html#maxspareservers">MaxSpareServers</A> settings.
-Furthermore, it respects <A HREF="mod/core.html#startservers">StartServers</A>
-in the following manner: if after one second at least StartServers new
-children have not been created, then create enough to pick up the slack.
-This is to say that the code tries to maintain both the number of children
-appropriate for the current load on the server, and respect your wishes
-with the StartServers parameter.
+<P>This code is designed to always respect the <A
+HREF="mod/mpm_common.html#maxclients">MaxClients</A>, <A
+HREF="mod/prefork.html#minspareservers">MinSpareServers</A>, and <A
+HREF="mod/prefork.html#maxspareservers">MaxSpareServers</A>
+settings. Furthermore, it respects <A
+HREF="mod/mpm_common.html#startservers">StartServers</A> in the
+following manner: if after one second at least StartServers new
+children have not been created, then create enough to pick up the
+slack. This is to say that the code tries to maintain both the number
+of children appropriate for the current load on the server, and
+respect your wishes with the StartServers parameter.</p>
<P>Users of the
<A HREF="mod/mod_status.html">status module</A>
@@ -112,31 +99,52 @@
restart was given.
<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
+<CODE>WINCH</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
+after sending the <CODE>WINCH</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><STRONG>Note:</STRONG> If your configuration file has errors in it when
-you issue a
-restart then your parent will not restart, it will exit with an error.
-In the case of graceful
-restarts it will also leave children running when it exits. (These are
-the children which are "gracefully exiting" by handling their last request.)
-This will cause problems if you attempt to restart the server -- it will
-not be able to bind to its listening ports. Before doing a restart, you
-can check the syntax of the configuration files with the <CODE>-t</CODE>
+<P><STRONG>Note:</STRONG> If your configuration file has errors in it
+when you issue a restart then your parent will not restart, it will
+exit with an error. In the case of graceful restarts it will also
+leave children running when it exits. (These are the children which
+are "gracefully exiting" by handling their last request.) This will
+cause problems if you attempt to restart the server -- it will not be
+able to bind to its listening ports. Before doing a restart, you can
+check the syntax of the configuration files with the <CODE>-t</CODE>
command line argument (see <A HREF="invoking.html">Starting
-Apache</A>). 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 httpd 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 httpd
+Apache</A>). 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 httpd 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 httpd
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.
+
+
+<H3>Restart Now</H3>
+
+<p><strong>Signal:</strong> HUP<br>
+<code>apachectl restart</code></p>
+
+<P>Sending the <CODE>HUP</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>Users of the
+<A HREF="mod/mod_status.html">status module</A>
+will notice that the server statistics are
+set to zero when a <CODE>HUP</CODE> is sent.
+
+<P><STRONG>Note:</STRONG> If your configuration file has errors in it when
+you issue a
+restart then your parent will not restart, it will exit with an error.
+See below for a method of avoiding this.
<H3>Appendix: signals and race conditions</H3>