repmgr standby register

repmgr standby register

add a standby's information to the &repmgr; metadata

## Description

`repmgr standby register` adds a standby's information to the &repmgr; metadata. This command needs to be executed to enable promote/follow operations and to allow &repmgrd; to work with the node. An existing standby can be registered using this command. Execute with the `--dry-run` option to check what would happen without actually registering the standby.

If providing the configuration file location with `-f/--config-file`, avoid using a relative path, as &repmgr; stores the configuration file location in the repmgr metadata for use when &repmgr; is executed remotely (e.g. during repmgr-standby-switchover). &repmgr; will attempt to convert the a relative path into an absolute one, but this may not be the same as the path you would explicitly provide (e.g. `./repmgr.conf` might be converted to `/path/to/./repmgr.conf`, whereas you'd normally write `/path/to/repmgr.conf`).

## Waiting for the the standby to start

By default, &repmgr; will wait 30 seconds for the standby to become available before aborting with a connection error. This is useful when setting up a standby from a script, as the standby may not have fully started up by the time `repmgr standby register` is executed.

To change the timeout, pass the desired value with the `--wait-start` option. A value of `0` will disable the timeout.

The timeout will be ignored if `-F/--force` was provided.

## Waiting for the registration to propagate to the standby

Depending on your environment and workload, it may take some time for the standby's node record to propagate from the primary to the standby. Some actions (such as starting &repmgrd;) require that the standby's node record is present and up-to-date to function correctly.

By providing the option `--wait-sync` to the `repmgr standby register` command, &repmgr; will wait until the record is synchronised before exiting. An optional timeout (in seconds) can be added to this option (e.g. `--wait-sync=60`).

## Registering an inactive node

Under some circumstances you may wish to register a standby which is not yet running; this can be the case when using provisioning tools to create a complex replication cluster, or if the node was not cloned by &repmgr;.

In this case, by using the `-F/--force` option and providing the connection parameters to the primary server, the standby can be registered even if it has not yet been started.

Connection parameters can either be provided either as a `conninfo` string (e.g. `-d 'host=node1 user=repmgr'` or as individual connection parameters (`-h/--host`, `-d/--dbname`, `-U/--user`, `-p/--port` etc.).

Similarly, with cascading replication it may be necessary to register a standby whose upstream node has not yet been registered - in this case, using `-F/--force` will result in the creation of an inactive placeholder record for the upstream node, which will however later need to be registered with the `-F/--force` option too.

When used with `repmgr standby register`, care should be taken that use of the `-F/--force` option does not result in an incorrectly configured cluster.

## Registering a node not cloned by repmgr

If you've cloned a standby using another method (e.g. barman's `barman recover` command), register the node as detailed in section repmgr-standby-register-inactive-node then execute repmgr standby clone --replication-conf-only to generate the appropriate replication configuration.

## Options

`--dry-run`

- Check prerequisites but don't actually register the standby.

`-F`/`--force`

- Overwrite an existing node record

`--upstream-node-id`

- ID of the upstream node to replicate from (optional)

`--wait-start`

- wait for the standby to start (timeout in seconds, default 30 seconds)

`--wait-sync`

- wait for the node record to synchronise to the standby (optional timeout in seconds)

## Event notifications

A `standby_register` event notification will be generated immediately after the node record is updated on the primary.

If the `--wait-sync` option is provided, a `standby_register_sync` event notification will be generated immediately after the node record has synchronised to the standby.

If provided, &repmgr; will substitute the placeholders `%p` with the node ID of the primary node, `%c` with its `conninfo` string, and `%a` with its node name.