I noticed an odd buildfarm failure today: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=sungazer&dt=2019-03-16%2012%3A12%3A20
of which the key bit seems to be 2019-03-16 15:20:43.835 UTC [10879304] 003_promote.pl LOG: received replication command: BASE_BACKUP LABEL 'pg_basebackup base backup' NOWAIT 2019-03-16 15:20:45.857 UTC [10879304] 003_promote.pl ERROR: could not request checkpoint because checkpointer not running 2019-03-16 15:20:47.227 UTC [61604144] LOG: received immediate shutdown request Digging in the buildfarm archives finds seven other occurrences of the same error in the past three months (I didn't look back further). The cause of this error is that RequestCheckpoint will give up and fail after just 2 seconds, which evidently is not long enough on slow or heavily loaded machines. Since there isn't any good reason why the checkpointer wouldn't be running, I'm inclined to swing a large hammer and kick this timeout up to 60 seconds. Thoughts? regards, tom lane