pg_autoctl_drop_node - Man Page

pg_autoctl drop node — pg_autoctl drop node

pg_autoctl drop node — Drop a node from the pg_auto_failover monitor

This command drops a Postgres node from the pg_auto_failover monitor:

usage: pg_autoctl drop node [ [ [ --pgdata ] [ --destroy ] ] | [ --monitor [ [ --hostname --pgport ] | [ --formation --name ] ] ] ]

--pgdata      path to data directory
--monitor     pg_auto_failover Monitor Postgres URL
--formation   pg_auto_failover formation
--name        drop the node with the given node name
--hostname    drop the node with given hostname and pgport
--pgport      drop the node with given hostname and pgport
--destroy     also destroy Postgres database
--force       force dropping the node from the monitor
--wait        how many seconds to wait, default to 60

Two modes of operations are implemented in the pg_autoctl drop node command.

When removing a node that still exists, it is possible to use pg_autoctl drop node --destroy to remove the node both from the monitor and also delete the local Postgres instance entirely.

When removing a node that doesn't exist physically anymore, or when the VM that used to host the node has been lost entirely, use either the pair of options --hostname and --pgport or the pair of options --formation and --name to match the node registration record on the monitor database, and get it removed from the known list of nodes on the monitor.

Then option --force can be used when the target node to remove does not exist anymore. When a node has been lost entirely, it's not going to be able to finish the procedure itself, and it is then possible to instruct the monitor of the situation.

--pgdata

Location of the Postgres node being managed locally. Defaults to the environment variable PGDATA. Use --monitor to connect to a monitor from anywhere, rather than the monitor URI used by a local Postgres node managed with pg_autoctl.

--monitor

Postgres URI used to connect to the monitor. Must use the autoctl_node username and target the pg_auto_failover database name. It is possible to show the Postgres URI from the monitor node using the command pg_autoctl show uri.

--hostname

Hostname of the Postgres node to remove from the monitor. Use either --name or --hostname --pgport, but not both.

--pgport

Port of the Postgres node to remove from the monitor. Use either --name or --hostname --pgport, but not both.

--name

Name of the node to remove from the monitor. Use either --name or --hostname --pgport, but not both.

--destroy

By default the pg_autoctl drop monitor commands does not remove the Postgres database for the monitor. When using --destroy, the Postgres installation is also deleted.

--force

By default a node is expected to reach the assigned state DROPPED when it is removed from the monitor, and has the opportunity to implement clean-up actions. When the target node to remove is not available anymore, it is possible to use the option --force to immediately remove the node from the monitor.

--wait

How many seconds to wait for the node to be dropped entirely. The command stops when the target node is not to be found on the monitor anymore, or when the timeout has elapsed, whichever comes first. The value 0 (zero) disables the timeout and disables waiting entirely, making the command async.

PGDATA

Postgres directory location. Can be used instead of the --pgdata option.

PG_AUTOCTL_MONITOR

Postgres URI to connect to the monitor node, can be used instead of the --monitor option.

PG_AUTOCTL_NODE_NAME

Node name to register to the monitor, can be used instead of the --name option.

PG_AUTOCTL_REPLICATION_QUORUM

Can be used instead of the --replication-quorum option.

PG_AUTOCTL_CANDIDATE_PRIORITY

Can be used instead of the --candidate-priority option.

PG_CONFIG

Can be set to the absolute path to the pg_config Postgres tool. This is mostly used in the context of building extensions, though it can be a useful way to select a Postgres version when several are installed on the same system.

PATH

Used the usual way mostly. Some entries that are searched in the PATH by the pg_autoctl command are expected to be found only once, to avoid mistakes with Postgres major versions.

PGHOST, PGPORT, PGDATABASE, PGUSER, PGCONNECT_TIMEOUT, ...

See the Postgres docs about Environment Variables for details.

TMPDIR

The pgcopydb command creates all its work files and directories in ${TMPDIR}/pgcopydb, and defaults to /tmp/pgcopydb.

XDG_CONFIG_HOME

The pg_autoctl command stores its configuration files in the standard place XDG_CONFIG_HOME. See the XDG Base Directory Specification.

XDG_DATA_HOME

The pg_autoctl command stores its internal states files in the standard place XDG_DATA_HOME, which defaults to ~/.local/share. See the XDG Base Directory Specification.

$ pg_autoctl drop node --destroy --pgdata ./node3
17:52:21 54201 INFO  Reaching assigned state "secondary"
17:52:21 54201 INFO  Removing node with name "node3" in formation "default" from the monitor
17:52:21 54201 WARN  Postgres is not running and we are in state secondary
17:52:21 54201 WARN  Failed to update the keeper's state from the local PostgreSQL instance, see above for details.
17:52:21 54201 INFO  Calling node_active for node default/4/0 with current state: PostgreSQL is running is false, sync_state is "", latest WAL LSN is 0/0.
17:52:21 54201 INFO  FSM transition to "dropped": This node is being dropped from the monitor
17:52:21 54201 INFO  Transition complete: current state is now "dropped"
17:52:21 54201 INFO  This node with id 4 in formation "default" and group 0 has been dropped from the monitor
17:52:21 54201 INFO  Stopping PostgreSQL at "/Users/dim/dev/MS/pg_auto_failover/tmux/node3"
17:52:21 54201 INFO  /Applications/Postgres.app/Contents/Versions/12/bin/pg_ctl --pgdata /Users/dim/dev/MS/pg_auto_failover/tmux/node3 --wait stop --mode fast
17:52:21 54201 INFO  /Applications/Postgres.app/Contents/Versions/12/bin/pg_ctl status -D /Users/dim/dev/MS/pg_auto_failover/tmux/node3 [3]
17:52:21 54201 INFO  pg_ctl: no server running
17:52:21 54201 INFO  pg_ctl stop failed, but PostgreSQL is not running anyway
17:52:21 54201 INFO  Removing "/Users/dim/dev/MS/pg_auto_failover/tmux/node3"
17:52:21 54201 INFO  Removing "/Users/dim/dev/MS/pg_auto_failover/tmux/config/pg_autoctl/Users/dim/dev/MS/pg_auto_failover/tmux/node3/pg_autoctl.cfg"

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