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$PostgreSQL: pgsql/doc/src/sgml/ref/gs_ctl-ref.sgml,v 1.51.2.1 2010/08/17 04:37:19 petere Exp $
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<refentry id="app-pg-ctl">
<refmeta>
<refentrytitle><application>gs_ctl</application></refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo>Application</refmiscinfo>
</refmeta>
<refnamediv>
<refname>gs_ctl</refname>
<refpurpose>initialize, start, stop, or restart a <productname>PostgreSQL</productname> server</refpurpose>
</refnamediv>
<indexterm zone="app-pg-ctl">
<primary>gs_ctl</primary>
</indexterm>
<refsynopsisdiv>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">init[db]</arg>
<arg>-s</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
<arg>-o <replaceable>options</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">start</arg>
<arg>-w</arg>
<arg>-t <replaceable>seconds</replaceable></arg>
<arg>-s</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
<arg>-l <replaceable>filename</replaceable></arg>
<arg>-o <replaceable>options</replaceable></arg>
<arg>-p <replaceable>path</replaceable></arg>
<arg>-c</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">stop</arg>
<arg>-W</arg>
<arg>-t <replaceable>seconds</replaceable></arg>
<arg>-s</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
<arg>-m
<group choice="plain">
<arg>s[mart]</arg>
<arg>f[ast]</arg>
<arg>i[mmediate]</arg>
</group>
</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">restart</arg>
<arg>-w</arg>
<arg>-t <replaceable>seconds</replaceable></arg>
<arg>-s</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
<arg>-c</arg>
<arg>-m
<group choice="plain">
<arg>s[mart]</arg>
<arg>f[ast]</arg>
<arg>i[mmediate]</arg>
</group>
</arg>
<arg>-o <replaceable>options</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">reload</arg>
<arg>-s</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">status</arg>
<arg>-D <replaceable>datadir</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">kill</arg>
<arg><replaceable>signal_name</replaceable></arg>
<arg><replaceable>process_id</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">register</arg>
<arg>-N <replaceable>servicename</replaceable></arg>
<arg>-U <replaceable>username</replaceable></arg>
<arg>-P <replaceable>password</replaceable></arg>
<arg>-D <replaceable>datadir</replaceable></arg>
<arg>-w</arg>
<arg>-t <replaceable>seconds</replaceable></arg>
<arg>-o <replaceable>options</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>gs_ctl</command>
<arg choice="plain">unregister</arg>
<arg>-N <replaceable>servicename</replaceable></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id="app-pg-ctl-description">
<title>Description</title>
<para>
<application>gs_ctl</application> is a utility for initializing a
<productname>PostgreSQL</productname> database cluster, starting,
stopping, or restarting the <productname>PostgreSQL</productname>
backend server (<xref linkend="app-gaussdb">), or displaying the
status of a running server. Although the server can be started
manually, <application>gs_ctl</application> encapsulates tasks such
as redirecting log output and properly detaching from the terminal
and process group. It also provides convenient options for
controlled shutdown.
</para>
<para>
The <option>init</option> or <option>gs_initdb</option> mode creates a
new
<productname>PostgreSQL</productname> database cluster. A database
cluster is a collection of databases that are managed by a single
server instance. This mode invokes the <command>gs_initdb</command>
command. See <xref linkend="app-gs_initdb"> for details.
</para>
<para>
In <option>start</option> mode, a new server is launched. The
server is started in the background, and standard input is attached
to <filename>/dev/null</filename> (or <literal>nul</> on Windows).
On Unix-like systems, by default, the server's standard output and
standard error are send to <application>gs_ctl</application>'s
standard output (not standard error). The standard output of
<application>gs_ctl</application> should then be redirected to a
file or piped to another process such as a log rotating program
like <application>rotatelogs</>; otherwise <command>gaussdb</command>
will write its output to the controlling terminal (from the
background) and will not leave the shell's process group. On
Windows, by default the server's standard output and standard error
are sent to the terminal. These default behaviors can be changed
by using <option>-l</option> to append server output to a log file.
</para>
<para>
In <option>stop</option> mode, the server that is running in
the specified data directory is shut down. Three different
shutdown methods can be selected with the <option>-m</option>
option: <quote>Smart</quote> mode waits for online backup mode
to finish and all the clients to disconnect. This is the default.
If the server is in recovery, recovery and streaming replication
will be terminated once all clients have disconnected.
<quote>Fast</quote> mode does not wait for clients to disconnect and
will terminate an online backup in progress. All active transactions are
rolled back and clients are forcibly disconnected, then the
server is shut down. <quote>Immediate</quote> mode will abort
all server processes without a clean shutdown. This will lead to
a recovery run on restart.
</para>
<para>
<option>restart</option> mode effectively executes a stop followed
by a start. This allows changing the <command>gaussdb</command>
command-line options.
</para>
<para>
<option>reload</option> mode simply sends the
<command>gaussdb</command> process a <systemitem>SIGHUP</>
signal, causing it to reread its configuration files
(<filename>postgresql.conf</filename>,
<filename>pg_hba.conf</filename>, etc.). This allows changing of
configuration-file options that do not require a complete restart
to take effect.
</para>
<para>
<option>status</option> mode checks whether a server is running in
the specified data directory. If it is, the <acronym>PID</acronym>
and the command line options that were used to invoke it are
displayed.
</para>
<para>
<option>kill</option> mode allows you to send a signal to a specified
process. This is particularly valuable for <productname>Microsoft Windows</>
which does not have a <application>kill</> command. Use
<literal>--help</> to see a list of supported signal names.
</para>
<para>
<option>register</option> mode allows you to register a system service
on <productname>Microsoft Windows</>.
</para>
<para>
<option>unregister</option> mode allows you to unregister a system service
on <productname>Microsoft Windows</>, previously registered with the
<option>register</option> command.
</para>
</refsect1>
<refsect1 id="app-pg-ctl-options">
<title>Options</title>
<variablelist>
<varlistentry>
<term><option>-c</option></term>
<listitem>
<para>
Attempt to allow server crashes to produce core files, on platforms
where this available, by lifting any soft resource limit placed on
them.
This is useful in debugging or diagnosing problems by allowing a
stack trace to be obtained from a failed server process.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-D <replaceable class="parameter">datadir</replaceable></option></term>
<listitem>
<para>
Specifies the file system location of the database files. If
this is omitted, the environment variable
<envar>PGDATA</envar> is used.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-l <replaceable class="parameter">filename</replaceable></option></term>
<listitem>
<para>
Append the server log output to
<replaceable>filename</replaceable>. If the file does not
exist, it is created. The <systemitem>umask</> is set to 077, so access to
the log file from other users is disallowed by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-m <replaceable class="parameter">mode</replaceable></option></term>
<listitem>
<para>
Specifies the shutdown mode. <replaceable>mode</replaceable>
can be <literal>smart</literal>, <literal>fast</literal>, or
<literal>immediate</literal>, or the first letter of one of
these three.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-o <replaceable class="parameter">options</replaceable></option></term>
<listitem>
<para>
Specifies options to be passed directly to the
<command>gaussdb</command> command.
</para>
<para>
The options are usually surrounded by single or double
quotes to ensure that they are passed through as a group.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-p <replaceable class="parameter">path</replaceable></option></term>
<listitem>
<para>
Specifies the location of the <filename>gaussdb</filename>
executable. By default the <filename>gaussdb</filename> executable is taken from the same
directory as <command>gs_ctl</command>, or failing that, the hard-wired
installation directory. It is not necessary to use this
option unless you are doing something unusual and get errors
that the <filename>gaussdb</filename> executable was not found.
</para>
<para>
In <literal>init</literal> mode, this option analogously
specifies the location of the <filename>gs_initdb</filename>
executable.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-s</option></term>
<listitem>
<para>
Only print errors, no informational messages.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-t</option></term>
<listitem>
<para>
The number of seconds to wait when waiting for start or shutdown
to complete.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-w</option></term>
<listitem>
<para>
Wait for the start or shutdown to complete. The default wait time
is 60 seconds. This is the default option for shutdowns. A successful
shutdown is indicated by removal of the <acronym>PID</acronym>
file. For starting up, a successful <command>gsql -l</command>
indicates success. <command>gs_ctl</command> will attempt to
use the proper port for <application>gsql</>. If the environment variable
<envar>PGPORT</envar> exists, that is used. Otherwise, it will see if a port
has been set in the <filename>postgresql.conf</filename> file.
If neither of those is used, it will use the default port that
<productname>PostgreSQL</productname> was compiled with
(5432 by default). When waiting, <command>gs_ctl</command> will
return an accurate exit code based on the success of the startup
or shutdown.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-W</option></term>
<listitem>
<para>
Do not wait for start or shutdown to complete. This is the
default for starts and restarts.
</para>
</listitem>
</varlistentry>
</variablelist>
<refsect2 id="app-pg-ctl-windows-options">
<title>Options for Windows</title>
<variablelist>
<varlistentry>
<term><option>-N <replaceable class="parameter">servicename</replaceable></option></term>
<listitem>
<para>
Name of the system service to register. The name will be used
as both the service name and the display name.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-P <replaceable class="parameter">password</replaceable></option></term>
<listitem>
<para>
Password for the user to start the service.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-U <replaceable class="parameter">username</replaceable></option></term>
<listitem>
<para>
User name for the user to start the service. For domain users, use the
format <literal>DOMAIN\username</literal>.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<refsect1>
<title>Environment</title>
<variablelist>
<varlistentry>
<term><envar>PGDATA</envar></term>
<listitem>
<para>
Default data directory location.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>PGHOST</envar></term>
<listitem>
<para>
Default host name or Unix-domain socket location for <xref
linkend="app-gsql"> (used by the <option>-w</option> option).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>PGPORT</envar></term>
<listitem>
<para>
Default port number for <xref linkend="app-gsql"> (used by the <option>-w</option> option).
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
For additional server variables, see <xref linkend="app-gaussdb">.
This utility, like most other <productname>PostgreSQL</> utilities,
also uses the environment variables supported by <application>libpq</>
(see <xref linkend="libpq-envars">).
</para>
</refsect1>
<refsect1>
<title>Files</title>
<variablelist>
<varlistentry>
<term><filename>gaussmaster.pid</filename></term>
<listitem>
<para>
The existence of this file in the data directory is used to help
<application>gs_ctl</application> determine if the server is
currently running or not.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>gaussmaster.opts</filename></term>
<listitem>
<para>If this file exists in the data directory,
<application>gs_ctl</application> (in <option>restart</option> mode)
will pass the contents of the file as options to
<application>gaussdb</application>, unless overridden
by the <option>-o</option> option. The contents of this file
are also displayed in <option>status</option> mode.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>postgresql.conf</filename></term>
<listitem>
<para>
This file, located in the data directory, is parsed to find the
proper port to use with <application>gsql</application> when the
<option>-w</option> is given in <option>start</option> mode.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
Waiting for complete start is not a well-defined operation and might
fail if access control is set up so that a local client cannot
connect without manual interaction (e.g., password authentication). For
additional connection variables, see <xref linkend="libpq-envars">,
and for passwords, also see <xref linkend="libpq-pgpass">.
</para>
</refsect1>
<refsect1 id="R1-APP-PGCTL-2">
<title>Examples</title>
<refsect2 id="R2-APP-PGCTL-3">
<title>Starting the Server</title>
<para>
To start up a server:
<screen>
<prompt>$</prompt> <userinput>gs_ctl start</userinput>
</screen>
</para>
<para>
An example of starting the server, blocking until the server has
come up is:
<screen>
<prompt>$</prompt> <userinput>gs_ctl -w start</userinput>
</screen>
</para>
<para>
For a server using port 5433, and
running without <function>fsync</function>, use:
<screen>
<prompt>$</prompt> <userinput>gs_ctl -o "-F -p 5433" start</userinput>
</screen>
</para>
</refsect2>
<refsect2 id="R2-APP-PGCTL-4">
<title>Stopping the Server</title>
<para>
<screen>
<prompt>$</prompt> <userinput>gs_ctl stop</userinput>
</screen>
stops the server. Using the <option>-m</option> switch allows one
to control <emphasis>how</emphasis> the backend shuts down.
</para>
</refsect2>
<refsect2 id="R2-APP-PGCTL-5">
<title>Restarting the Server</title>
<para>
Restarting the server is almost equivalent to stopping the
server and starting it again
except that <command>gs_ctl</command> saves and reuses the command line options that
were passed to the previously running instance. To restart
the server in the simplest form, use:
<screen>
<prompt>$</prompt> <userinput>gs_ctl restart</userinput>
</screen>
</para>
<para>
To restart server,
waiting for it to shut down and to come up:
<screen>
<prompt>$</prompt> <userinput>gs_ctl -w restart</userinput>
</screen>
</para>
<para>
To restart using port 5433 and disabling <function>fsync</> after restarting:
<screen>
<prompt>$</prompt> <userinput>gs_ctl -o "-F -p 5433" restart</userinput>
</screen>
</para>
</refsect2>
<refsect2 id="R2-APP-PGCTL-6">
<title>Showing the Server Status</title>
<para>
Here is a sample status output from
<application>gs_ctl</application>:
<screen>
<prompt>$</prompt> <userinput>gs_ctl status</userinput>
<computeroutput>
gs_ctl: server is running (pid: 13718)
Command line was:
/usr/local/pgsql/bin/gaussdb '-D' '/usr/local/pgsql/data' '-p' '5433' '-B' '128'
</computeroutput>
</screen>
This is the command line that would be invoked in restart mode.
</para>
</refsect2>
</refsect1>
<refsect1>
<title>See Also</title>
<simplelist type="inline">
<member><xref linkend="app-gs_initdb"></member>
<member><xref linkend="app-gaussdb"></member>
</simplelist>
</refsect1>
</refentry>