When WalSndCaughtUp, sleep only in WalSndWaitForWal(). Before sleeping, WalSndWaitForWal() sends a keepalive if MyWalSnd->write < sentPtr. That is important in logical replication. When the latest physical LSN yields no logical replication messages (a common case), that keepalive elicits a reply, and processing the reply updates pg_stat_replication.replay_lsn. WalSndLoop() lacks that; when WalSndLoop() slept, replay_lsn advancement could stall until wal_receiver_status_interval elapsed. This sometimes stalled src/test/subscription/t/001_rep_changes.pl for up to 10s.
Discussion: https://postgr.es/m/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/421685812290406daea58b78dfab0346eb683bbb Modified Files -------------- src/backend/replication/walsender.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)
