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diff --git a/doc/src/sgml/html/server-shutdown.html b/doc/src/sgml/html/server-shutdown.html new file mode 100644 index 0000000..1119b56 --- /dev/null +++ b/doc/src/sgml/html/server-shutdown.html @@ -0,0 +1,72 @@ +<?xml version="1.0" encoding="UTF-8" standalone="no"?> +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>19.5. Shutting Down the Server</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="kernel-resources.html" title="19.4. Managing Kernel Resources" /><link rel="next" href="upgrading.html" title="19.6. Upgrading a PostgreSQL Cluster" /></head><body id="docContent" class="container-fluid col-10"><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">19.5. Shutting Down the Server</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="kernel-resources.html" title="19.4. Managing Kernel Resources">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="runtime.html" title="Chapter 19. Server Setup and Operation">Up</a></td><th width="60%" align="center">Chapter 19. Server Setup and Operation</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="upgrading.html" title="19.6. Upgrading a PostgreSQL Cluster">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="SERVER-SHUTDOWN"><div class="titlepage"><div><div><h2 class="title" style="clear: both">19.5. Shutting Down the Server</h2></div></div></div><a id="id-1.6.6.8.2" class="indexterm"></a><p> + There are several ways to shut down the database server. + Under the hood, they all reduce to sending a signal to the supervisor + <code class="command">postgres</code> process. + </p><p> + If you are using a pre-packaged version + of <span class="productname">PostgreSQL</span>, and you used its provisions + for starting the server, then you should also use its provisions for + stopping the server. Consult the package-level documentation for + details. + </p><p> + When managing the server directly, you can control the type of shutdown + by sending different signals to the <code class="command">postgres</code> + process: + + </p><div class="variablelist"><dl class="variablelist"><dt><span class="term"><span class="systemitem">SIGTERM</span><a id="id-1.6.6.8.5.2.1.1.2" class="indexterm"></a></span></dt><dd><p> + This is the <em class="firstterm">Smart Shutdown</em> mode. + After receiving <span class="systemitem">SIGTERM</span>, the server + disallows new connections, but lets existing sessions end their + work normally. It shuts down only after all of the sessions terminate. + If the server is in online backup mode, it additionally waits + until online backup mode is no longer active. While backup mode is + active, new connections will still be allowed, but only to superusers + (this exception allows a superuser to connect to terminate + online backup mode). If the server is in recovery when a smart + shutdown is requested, recovery and streaming replication will be + stopped only after all regular sessions have terminated. + </p></dd><dt><span class="term"><span class="systemitem">SIGINT</span><a id="id-1.6.6.8.5.2.2.1.2" class="indexterm"></a></span></dt><dd><p> + This is the <em class="firstterm">Fast Shutdown</em> mode. + The server disallows new connections and sends all existing + server processes <span class="systemitem">SIGTERM</span>, which will cause them + to abort their current transactions and exit promptly. It then + waits for all server processes to exit and finally shuts down. + If the server is in online backup mode, backup mode will be + terminated, rendering the backup useless. + </p></dd><dt><span class="term"><span class="systemitem">SIGQUIT</span><a id="id-1.6.6.8.5.2.3.1.2" class="indexterm"></a></span></dt><dd><p> + This is the <em class="firstterm">Immediate Shutdown</em> mode. + The server will send <span class="systemitem">SIGQUIT</span> to all child + processes and wait for them to terminate. If any do not terminate + within 5 seconds, they will be sent <span class="systemitem">SIGKILL</span>. + The supervisor server process exits as soon as all child processes have + exited, without doing normal database shutdown processing. + This will lead to recovery (by + replaying the WAL log) upon next start-up. This is recommended + only in emergencies. + </p></dd></dl></div><p> + </p><p> + The <a class="xref" href="app-pg-ctl.html" title="pg_ctl"><span class="refentrytitle"><span class="application">pg_ctl</span></span></a> program provides a convenient + interface for sending these signals to shut down the server. + Alternatively, you can send the signal directly using <code class="command">kill</code> + on non-Windows systems. + The <acronym class="acronym">PID</acronym> of the <code class="command">postgres</code> process can be + found using the <code class="command">ps</code> program, or from the file + <code class="filename">postmaster.pid</code> in the data directory. For + example, to do a fast shutdown: +</p><pre class="screen"> +$ <strong class="userinput"><code>kill -INT `head -1 /usr/local/pgsql/data/postmaster.pid`</code></strong> +</pre><p> + </p><div class="important"><h3 class="title">Important</h3><p> + It is best not to use <span class="systemitem">SIGKILL</span> to shut down the + server. Doing so will prevent the server from releasing shared memory and + semaphores. Furthermore, <span class="systemitem">SIGKILL</span> kills + the <code class="command">postgres</code> process without letting it relay the + signal to its subprocesses, so it might be necessary to kill the + individual subprocesses by hand as well. + </p></div><p> + To terminate an individual session while allowing other sessions to + continue, use <code class="function">pg_terminate_backend()</code> (see <a class="xref" href="functions-admin.html#FUNCTIONS-ADMIN-SIGNAL-TABLE" title="Table 9.86. Server Signaling Functions">Table 9.86</a>) or send a + <span class="systemitem">SIGTERM</span> signal to the child process associated with + the session. + </p></div><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navfooter"><hr></hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="kernel-resources.html" title="19.4. Managing Kernel Resources">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="runtime.html" title="Chapter 19. Server Setup and Operation">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="upgrading.html" title="19.6. Upgrading a PostgreSQL Cluster">Next</a></td></tr><tr><td width="40%" align="left" valign="top">19.4. Managing Kernel Resources </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 14.5 Documentation">Home</a></td><td width="40%" align="right" valign="top"> 19.6. Upgrading a <span xmlns="http://www.w3.org/1999/xhtml" class="productname">PostgreSQL</span> Cluster</td></tr></table></div></body></html>
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