On 28/02/17 04:27, Kyotaro HORIGUCHI wrote: > Hello. > > Although replication slot is helpful to avoid unwanted WAL > deletion, on the other hand it can cause a disastrous situation > by keeping WAL segments without a limit. Removing the causal > repslot will save this situation but it is not doable if the > standby is active. We should do a rather complex and forcible > steps to relieve the situation especially in an automatic > manner. (As for me, specifically in an HA cluster.) >
I agree that that it should be possible to limit how much WAL slot keeps. > This patch adds a GUC to put a limit to the number of segments > that replication slots can keep. Hitting the limit during > checkpoint shows a warining and the segments older than the limit > are removed. > >> WARNING: restart LSN of replication slots is ignored by checkpoint >> DETAIL: Some replication slots lose required WAL segnents to continue. > However this is dangerous as logical replication slot does not consider it error when too old LSN is requested so we'd continue replication, hiding data loss. -- Petr Jelinek http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
