18.2. Pausing/unpausing repmgrd

To pause repmgrd, execute repmgr daemon pause, e.g.:

$ repmgr -f /etc/repmgr.conf daemon pause
NOTICE: node 1 (node1) paused
NOTICE: node 2 (node2) paused
NOTICE: node 3 (node3) paused

The state of repmgrd on each node can be checked with repmgr daemon status, e.g.:

$ repmgr -f /etc/repmgr.conf daemon status
 ID | Name  | Role    | Status  | repmgrd | PID  | Paused?
----+-------+---------+---------+---------+------+---------
 1  | node1 | primary | running | running | 7851 | yes
 2  | node2 | standby | running | running | 7889 | yes
 3  | node3 | standby | running | running | 7918 | yes

Note: If executing a switchover with repmgr standby switchover, repmgr will automatically pause/unpause repmgrd as part of the switchover process.

If the primary (in this example, node1) is stopped, repmgrd running on one of the standbys (here: node2) will react like this:

[2018-09-20 12:22:21] [WARNING] unable to connect to upstream node "node1" (node ID: 1)
[2018-09-20 12:22:21] [INFO] checking state of node 1, 1 of 5 attempts
[2018-09-20 12:22:21] [INFO] sleeping 1 seconds until next reconnection attempt
...
[2018-09-20 12:22:24] [INFO] sleeping 1 seconds until next reconnection attempt
[2018-09-20 12:22:25] [INFO] checking state of node 1, 5 of 5 attempts
[2018-09-20 12:22:25] [WARNING] unable to reconnect to node 1 after 5 attempts
[2018-09-20 12:22:25] [NOTICE] node is paused
[2018-09-20 12:22:33] [INFO] node "node2" (node ID: 2) monitoring upstream node "node1" (node ID: 1) in degraded state
[2018-09-20 12:22:33] [DETAIL] repmgrd paused by administrator
[2018-09-20 12:22:33] [HINT] execute "repmgr daemon unpause" to resume normal failover mode

If the primary becomes available again (e.g. following a software upgrade), repmgrd will automatically reconnect, e.g.:

[2018-09-20 13:12:41] [NOTICE] reconnected to upstream node 1 after 8 seconds, resuming monitoring

To unpause repmgrd, execute repmgr daemon unpause, e.g.:

$ repmgr -f /etc/repmgr.conf daemon pause
NOTICE: node 1 (node1) unpaused
NOTICE: node 2 (node2) unpaused
NOTICE: node 3 (node3) unpaused

Note: If the previous primary is no longer accessible when repmgrd is unpaused, no failover action will be taken. Instead, a new primary must be manually promoted using repmgr standby promote, and any standbys attached to the new primary with repmgr standby follow.

This is to prevent repmgr daemon unpause resulting in the automatic promotion of a new primary, which may be a problem particularly in larger clusters, where repmgrd could select a different promotion candidate to the one intended by the administrator.

18.2.1. Details on the repmgrd pausing mechanism

The pause state of each node will be stored over a PostgreSQL restart.

repmgr daemon pause and repmgr daemon unpause can be executed even if repmgrd is not running; in this case, repmgrd will start up in whichever pause state has been set.

Note: repmgr daemon pause and repmgr daemon unpause do not stop/start repmgrd.