camptocamp / docker-postgres-collectd Goto Github PK

after a pg_ctl promote, the recovery control functions (pg_last_xlog_receive_location() and pg_last_xlog_replay_location()) still return the last values instead of NULL. It is explained in the PG documentation:

If recovery has completed then this value will remain static at the value of the last WAL record applied during that recovery. When the server has been started normally without recovery the function returns NULL.

To avoid having wrong values in prometheus/grafana we have to add a condition before using these functions, something like IF (SELECT pg_is_in_recovery() THEN SELECT pg_last_xlog_receive_location() ...

This will prevent creating new databases with this error message:

ERROR:  source database "template1" is being accessed by other users
DETAIL:  There is 1 other session using the database