Files
repmgr/doc/event-notifications.xml
Ian Barwick e7e62f7f35 repmgrd: add %p event notification parameter for "repmgrd_failover_promote"
This enables an event notification script to identify the former primary
node.
2021-09-28 10:25:27 +09:00

283 lines
9.2 KiB
XML

<chapter id="event-notifications" xreflabel="event notifications">
<title>Event Notifications</title>
<indexterm>
<primary>event notifications</primary>
</indexterm>
<para>
Each time &repmgr; or &repmgrd; perform a significant event, a record
of that event is written into the <literal>repmgr.events</literal> table together with
a timestamp, an indication of failure or success, and further details
if appropriate. This is useful for gaining an overview of events
affecting the replication cluster. However note that this table has
advisory character and should be used in combination with the &repmgr;
and PostgreSQL logs to obtain details of any events.
</para>
<para>
Example output after a primary was registered and a standby cloned
and registered:
<programlisting>
repmgr=# SELECT * from repmgr.events ;
node_id | event | successful | event_timestamp | details
---------+------------------+------------+-------------------------------+-------------------------------------------------------------------------------------
1 | primary_register | t | 2016-01-08 15:04:39.781733+09 |
2 | standby_clone | t | 2016-01-08 15:04:49.530001+09 | Cloned from host 'repmgr_node1', port 5432; backup method: pg_basebackup; --force: N
2 | standby_register | t | 2016-01-08 15:04:50.621292+09 |
(3 rows)</programlisting>
</para>
<para>
Alternatively, use <xref linkend="repmgr-cluster-event"/> to output a
formatted list of events.
</para>
<para>
Additionally, event notifications can be passed to a user-defined program
or script which can take further action, e.g. send email notifications.
This is done by setting the <literal>event_notification_command</literal> parameter in
<filename>repmgr.conf</filename>.
</para>
<para>
The following format placeholders are provided for all event notifications:
</para>
<variablelist>
<varlistentry>
<term><option>%n</option></term>
<listitem>
<para>
node ID
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%e</option></term>
<listitem>
<para>
event type
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%s</option></term>
<listitem>
<para>
success (1) or failure (0)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%t</option></term>
<listitem>
<para>
timestamp
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%d</option></term>
<listitem>
<para>
details
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The values provided for <literal>%t</literal> and <literal>%d</literal>
may contain spaces, so should be quoted in the provided command
configuration, e.g.:
<programlisting>
event_notification_command='/path/to/some/script %n %e %s "%t" "%d"'</programlisting>
</para>
<para>
The following parameters are provided for a subset of event notifications; their meaning may
change according to context:
</para>
<variablelist>
<varlistentry>
<term><option>%p</option></term>
<listitem>
<para>
node ID of the current primary (<xref linkend="repmgr-standby-register"/> and <xref linkend="repmgr-standby-follow"/>)
</para>
<para>
node ID of the demoted primary (<xref linkend="repmgr-standby-switchover"/> only)
</para>
<para>
node ID of the former primary (<literal>repmgrd_failover_promote</literal> only)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%c</option></term>
<listitem>
<para>
<literal>conninfo</literal> string of the primary node
(<xref linkend="repmgr-standby-register"/> and <xref linkend="repmgr-standby-follow"/>)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>%a</option></term>
<listitem>
<para>
name of the current primary node (<xref linkend="repmgr-standby-register"/> and <xref linkend="repmgr-standby-follow"/>)
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The values provided for <literal>%c</literal> and <literal>%a</literal>
may contain spaces, so should always be quoted.
</para>
<para>
By default, all notification types will be passed to the designated script;
the notification types can be filtered to explicitly named ones using the
<varname>event_notifications</varname> parameter, e.g.:
<programlisting>
event_notifications='primary_register,standby_register,witness_register'</programlisting>
</para>
<para>
Events generated by the &repmgr; command:
<itemizedlist spacing="compact" mark="bullet">
<listitem>
<simpara><literal><link linkend="repmgr-primary-register-events">cluster_created</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-primary-register-events">primary_register</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-primary-unregister-events">primary_unregister</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-clone-events">standby_clone</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-register-events">standby_register</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-register-events">standby_register_sync</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-unregister-events">standby_unregister</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-promote-events">standby_promote</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-follow-events">standby_follow</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-standby-switchover-events">standby_switchover</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-witness-register-events">witness_register</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-witness-unregister-events">witness_unregister</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-node-rejoin-events">node_rejoin</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgr-cluster-cleanup-events">cluster_cleanup</link></literal></simpara>
</listitem>
</itemizedlist>
</para>
<para>
Events generated by &repmgrd; (streaming replication mode):
<itemizedlist spacing="compact" mark="bullet">
<listitem>
<simpara><literal>repmgrd_start</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_shutdown</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_reload</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_failover_promote</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_failover_follow</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_failover_aborted</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_standby_reconnect</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_promote_error</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_local_disconnect</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_local_reconnect</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_upstream_disconnect</literal></simpara>
</listitem>
<listitem>
<simpara><literal>repmgrd_upstream_reconnect</literal></simpara>
</listitem>
<listitem>
<simpara><literal>standby_disconnect_manual</literal></simpara>
</listitem>
<listitem>
<simpara><literal>standby_failure</literal></simpara>
</listitem>
<listitem>
<simpara><literal>standby_recovery</literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgrd-primary-child-disconnection-events">child_node_disconnect</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgrd-primary-child-disconnection-events">child_node_reconnect</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgrd-primary-child-disconnection-events">child_node_new_connect</link></literal></simpara>
</listitem>
<listitem>
<simpara><literal><link linkend="repmgrd-primary-child-disconnection-events">child_nodes_disconnect_command</link></literal></simpara>
</listitem>
</itemizedlist>
</para>
<para>
Note that under some circumstances (e.g. when no replication cluster primary
could be located), it will not be possible to write an entry into the
<literal>repmgr.events</literal>
table, in which case executing a script via <varname>event_notification_command</varname>
can serve as a fallback by generating some form of notification.
</para>
</chapter>