From 0d36d9f2b9a2178bb19ffbe663e39818f51a0f82 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Fri, 6 Feb 2015 11:18:14 +0200 Subject: [PATCH] Report WAL flush, not insert, position in replication IDENTIFY_SYSTEM When beginning streaming replication, the client usually issues the IDENTIFY_SYSTEM command, which used to return the current WAL insert position. That's not suitable for the intended purpose of that field, however. pg_receivexlog uses it to start replication from the reported point, but if it hasn't been flushed to disk yet, it will fail. Change IDENTIFY_SYSTEM to report the flush position instead. Backpatch to 9.1 and above. 9.0 doesn't report any WAL position. --- doc/src/sgml/protocol.sgml | 2 +- src/backend/replication/walsender.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index 8a0755eea9..21894f614e 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -1353,7 +1353,7 @@ The commands accepted in walsender mode are: - Current xlog write location. Useful to get a known location in the + Current xlog flush location. Useful to get a known location in the transaction log where streaming can start. diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 33d038a377..ee6eb2f21c 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -289,7 +289,7 @@ IdentifySystem(void) GetSystemIdentifier()); snprintf(tli, sizeof(tli), "%u", ThisTimeLineID); - logptr = GetInsertRecPtr(); + logptr = GetFlushRecPtr(); snprintf(xpos, sizeof(xpos), "%X/%X", logptr.xlogid, logptr.xrecoff); -- 2.40.0