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doc: define entity for repmgrd

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Ian Barwick
2019-05-01 10:36:54 +09:00
parent 4d1e11533e
commit dbeffbf29a
31 changed files with 298 additions and 297 deletions
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74
doc/repmgrd-configuration.sgml
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@@ -8,13 +8,13 @@
<title>repmgrd setup and configuration</title>
<para>
<application>repmgrd</application> is a daemon which runs on each PostgreSQL node,
&repmgrd; is a daemon which runs on each PostgreSQL node,
monitoring the local node, and (unless it's the primary node) the upstream server
(the primary server or with cascading replication, another standby) which it's
connected to.
</para>
<para>
<application>repmgrd</application> can be configured to provide failover
&repmgrd; can be configured to provide failover
capability in case the primary upstream node becomes unreachable, and/or
provide monitoring data to the &repmgr; metadatabase.
</para>
@@ -23,7 +23,7 @@
<title>repmgrd configuration</title>
<para>
To use <application>repmgrd</application>, its associated function library <emphasis>must</emphasis> be
To use &repmgrd;, its associated function library <emphasis>must</emphasis> be
included via <filename>postgresql.conf</filename> with:
<programlisting>
@@ -35,7 +35,7 @@
</para>
<para>
The following configuraton options apply to <application>repmgrd</application> in all circumstances:
The following configuraton options apply to &repmgrd; in all circumstances:
</para>
<variablelist>
@@ -62,7 +62,7 @@
<listitem>
<para>
The option <option>connection_check_type</option> is used to select the method
<application>repmgrd</application> uses to determine whether the upstream node is available.
&repmgrd; uses to determine whether the upstream node is available.
</para>
<para>
Possible values are:
@@ -132,7 +132,7 @@
<term><option>degraded_monitoring_timeout</option></term>
<listitem>
<para>
Interval (in seconds) after which <application>repmgrd</application> will terminate if
Interval (in seconds) after which &repmgrd; will terminate if
either of the servers (local node and or upstream node) being monitored is no longer available
(<link linkend="repmgrd-degraded-monitoring">degraded monitoring mode</link>).
</para>
@@ -152,7 +152,7 @@
<title>Required configuration for automatic failover</title>
<para>
The following <application>repmgrd</application> options <emphasis>must</emphasis> be set in
The following &repmgrd; options <emphasis>must</emphasis> be set in
<filename>repmgr.conf</filename>:
<itemizedlist spacing="compact" mark="bullet">
@@ -192,7 +192,7 @@
</para>
<note>
<para>
If <option>failover</option> is set to <literal>manual</literal>, <application>repmgrd</application>
If <option>failover</option> is set to <literal>manual</literal>, &repmgrd;
will not take any action if a failover situation is detected, and the node may need to
be modified manually (e.g. by executing <command><link linkend="repmgr-standby-follow">repmgr standby follow</link></command>).
</para>
@@ -209,7 +209,7 @@
<listitem>
<para>
The program or script defined in <option>promote_command</option> will be executed
in a failover situation when <application>repmgrd</application> determines that
in a failover situation when &repmgrd; determines that
the current node is to become the new primary node.
</para>
<para>
@@ -231,8 +231,8 @@
<para>
Note that the <literal>--log-to-file</literal> option will cause
output generated by the &repmgr; command, when executed by <application>repmgrd</application>,
to be logged to the same destination configured to receive log output for <application>repmgrd</application>.
output generated by the &repmgr; command, when executed by &repmgrd;,
to be logged to the same destination configured to receive log output for &repmgrd;.
</para>
<note>
<para>
@@ -252,7 +252,7 @@
<listitem>
<para>
The program or script defined in <option>follow_command</option> will be executed
in a failover situation when <application>repmgrd</application> determines that
in a failover situation when &repmgrd; determines that
the current node is to follow the new primary node.
</para>
<para>
@@ -263,7 +263,7 @@
The <option>follow_command</option> parameter
should provide the <literal>--upstream-node-id=%n</literal>
option to <command>repmgr standby follow</command>; the <literal>%n</literal> will be replaced by
<application>repmgrd</application> with the ID of the new primary node. If this is not provided,
&repmgrd; with the ID of the new primary node. If this is not provided,
<command>repmgr standby follow</command> will attempt to determine the new primary by itself, but if the
original primary comes back online after the new primary is promoted, there is a risk that
<command>repmgr standby follow</command> will result in the node continuing to follow
@@ -284,8 +284,8 @@
<para>
Note that the <literal>--log-to-file</literal> option will cause
output generated by the &repmgr; command, when executed by <application>repmgrd</application>,
to be logged to the same destination configured to receive log output for <application>repmgrd</application>.
output generated by the &repmgr; command, when executed by &repmgrd;,
to be logged to the same destination configured to receive log output for &repmgrd;.
</para>
<note>
<para>
@@ -337,7 +337,7 @@
<listitem>
<para>
User-defined script to execute for an external mechanism to validate the failover
decision made by <application>repmgrd</application>.
decision made by &repmgrd;.
</para>
<note>
<para>
@@ -408,7 +408,7 @@
for this option.
</para>
<para>
<application>repmgrd</application> will refuse to start if this option is set
&repmgrd; will refuse to start if this option is set
but either of these prerequisites is not met.
</para>
</note>
@@ -469,14 +469,14 @@
</indexterm>
<title>PostgreSQL service configuration</title>
<para>
If using automatic failover, currently <application>repmgrd</application> will need to execute
If using automatic failover, currently &repmgrd; will need to execute
<link linkend="repmgr-standby-follow"><command>repmgr standby follow</command></link>
to restart PostgreSQL on standbys to have them follow a new primary.
</para>
<para>
To ensure this happens smoothly, it's essential to provide the appropriate system/service restart
command appropriate to your operating system via <varname>service_restart_command</varname>
in <filename>repmgr.conf</filename>. If you don't do this, <application>repmgrd</application>
in <filename>repmgr.conf</filename>. If you don't do this, &repmgrd;
will default to using <command>pg_ctl</command>, which can result in unexpected problems,
particularly on <application>systemd</application>-based systems.
</para>
@@ -549,21 +549,21 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
</indexterm>
<title>Applying configuration changes to repmgrd</title>
<para>
To apply configuration file changes to a running <application>repmgrd</application>
daemon, execute the operating system's <application>repmgrd</application> service reload command
To apply configuration file changes to a running &repmgrd;
daemon, execute the operating system's &repmgrd; service reload command
(see <xref linkend="appendix-packages"> for examples),
or for instances which were manually started, execute <command>kill -HUP</command>, e.g.
<command>kill -HUP `cat /tmp/repmgrd.pid`</command>.
</para>
<tip>
<para>
Check the <application>repmgrd</application> log to see what changes were
Check the &repmgrd; log to see what changes were
applied, or if any issues were encountered when reloading the configuration.
</para>
</tip>
<para>
Note that only the following subset of configuration file parameters can be changed on a
running <application>repmgrd</application> daemon:
running &repmgrd; daemon:
</para>
<itemizedlist spacing="compact" mark="bullet">
@@ -770,7 +770,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
<note>
<para>
After executing <command><link linkend="repmgr-standby-register">repmgr standby register --force</link></command>,
<application>repmgrd</application> <emphasis>must</emphasis> be restarted for the changes to take effect.
&repmgrd; <emphasis>must</emphasis> be restarted for the changes to take effect.
</para>
</note>
@@ -785,7 +785,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
</indexterm>
<title>repmgrd daemon</title>
<para>
If installed from a package, the <application>repmgrd</application> can be started
If installed from a package, the &repmgrd; can be started
via the operating system's service command, e.g. in <application>systemd</application>
using <command>systemctl</command>.
</para>
@@ -796,7 +796,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
<para>
The commands <link linkend="repmgr-daemon-start"><command>repmgr daemon start</command></link> and
<link linkend="repmgr-daemon-stop"><command>repmgr daemon stop</command></link> can be used
as convenience wrappers to start and stop <application>repmgrd</application>.
as convenience wrappers to start and stop &repmgrd;.
</para>
<important>
<para>
@@ -808,7 +808,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
</para>
</important>
<para>
<application>repmgrd</application> can be started manually like this:
&repmgrd; can be started manually like this:
<programlisting>
repmgrd -f /etc/repmgr.conf --pid-file /tmp/repmgrd.pid</programlisting>
and stopped with <command>kill `cat /tmp/repmgrd.pid`</command>. Adjust paths as appropriate.
@@ -825,7 +825,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
</indexterm>
<title>repmgrd's PID file</title>
<para>
<application>repmgrd</application> will generate a PID file by default.
&repmgrd; will generate a PID file by default.
</para>
<note>
<simpara>
@@ -845,12 +845,12 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
<option>--pid-file</option> may be deprecated in future releases.
</para>
<para>
If a PID file location was specified by the package maintainer, <application>repmgrd</application>
If a PID file location was specified by the package maintainer, &repmgrd;
will use that. This only applies if &repmgr; was installed from a package and the package
maintainer has specified the PID file location.
</para>
<para>
If none of the above apply, <application>repmgrd</application> will create a PID file
If none of the above apply, &repmgrd; will create a PID file
in the operating system's temporary directory (as setermined by the environment variable
<varname>TMPDIR</varname>, or if that is not set, will use <filename>/tmp</filename>).
</para>
@@ -859,10 +859,10 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
<option>--no-pid-file</option>.
</para>
<para>
To see which PID file <application>repmgrd</application> would use, execute <application>repmgrd</application>
with the option <option>--show-pid-file</option>. <application>repmgrd</application>
To see which PID file &repmgrd; would use, execute &repmgrd;
with the option <option>--show-pid-file</option>. &repmgrd;
will not start if this option is provided. Note that the value shown is the
file <application>repmgrd</application> would use next time it starts, and is
file &repmgrd; would use next time it starts, and is
not necessarily the PID file currently in use.
</para>
</sect2>
@@ -881,7 +881,7 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
<para>
If &repmgr; was installed from Debian/Ubuntu packages, additional configuration
is required before <application>repmgrd</application> is started as a daemon.
is required before &repmgrd; is started as a daemon.
</para>
<para>
This is done via the file <filename>/etc/default/repmgrd</filename>, which by default
@@ -920,12 +920,12 @@ REPMGRD_OPTS="--daemonize=false"
</para>
</tip>
<para>
From <application>repmgrd</application> 4.1, ensure <varname>REPMGRD_OPTS</varname> includes
From &repmgrd; 4.1, ensure <varname>REPMGRD_OPTS</varname> includes
<option>--daemonize=false</option>, as daemonization is handled by the service command.
</para>
<para>
If using <application>systemd</application>, you may need to execute <command>systemctl daemon-reload</command>.
Also, if you attempted to start <application>repmgrd</application> using <command>systemctl start repmgrd</command>,
Also, if you attempted to start &repmgrd; using <command>systemctl start repmgrd</command>,
you'll need to execute <command>systemctl stop repmgrd</command>. Because that's how <application>systemd</application>
rolls.
</para>
@@ -972,7 +972,7 @@ REPMGRD_OPTS="--daemonize=false"
<title>repmgrd log rotation</title>
<para>
To ensure the current <application>repmgrd</application> logfile
To ensure the current &repmgrd; logfile
(specified in <filename>repmgr.conf</filename> with the parameter
<option>log_file</option>) does not grow indefinitely, configure your
system's <command>logrotate</command> to regularly rotate it.