From 314cbfc5da988eff8998655158f84c9815ecfbcd Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Tue, 29 Mar 2016 21:16:12 -0400 Subject: Add new replication mode synchronous_commit = 'remote_apply'. In this mode, the master waits for the transaction to be applied on the remote side, not just written to disk. That means that you can count on a transaction started on the standby to see all commits previously acknowledged by the master. To make this work, the standby sends a reply after replaying each commit record generated with synchronous_commit >= 'remote_apply'. This introduces a small inefficiency: the extra replies will be sent even by standbys that aren't the current synchronous standby. But previously-existing synchronous_commit levels make no attempt at all to optimize which replies are sent based on what the primary cares about, so this is no worse, and at least avoids any extra replies for people not using the feature at all. Thomas Munro, reviewed by Michael Paquier and by me. Some additional tweaks by me. --- src/backend/utils/misc/guc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'src/backend/utils/misc/guc.c') diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 65a6cd4404f..06cb1660eb6 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -345,12 +345,13 @@ static const struct config_enum_entry constraint_exclusion_options[] = { }; /* - * Although only "on", "off", "remote_write", and "local" are documented, we - * accept all the likely variants of "on" and "off". + * Although only "on", "off", "remote_apply", "remote_write", and "local" are + * documented, we accept all the likely variants of "on" and "off". */ static const struct config_enum_entry synchronous_commit_options[] = { {"local", SYNCHRONOUS_COMMIT_LOCAL_FLUSH, false}, {"remote_write", SYNCHRONOUS_COMMIT_REMOTE_WRITE, false}, + {"remote_apply", SYNCHRONOUS_COMMIT_REMOTE_APPLY, false}, {"on", SYNCHRONOUS_COMMIT_ON, false}, {"off", SYNCHRONOUS_COMMIT_OFF, false}, {"true", SYNCHRONOUS_COMMIT_ON, true}, -- cgit v1.2.3