From 24c5f1a103ce6656a5cb430d9a996c34e61ab2a5 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Wed, 30 Mar 2016 20:07:05 -0300 Subject: Enable logical slots to follow timeline switches MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When decoding from a logical slot, it's necessary for xlog reading to be able to read xlog from historical (i.e. not current) timelines; otherwise, decoding fails after failover, because the archives are in the historical timeline. This is required to make "failover logical slots" possible; it currently has no other use, although theoretically it could be used by an extension that creates a slot on a standby and continues to replay from the slot when the standby is promoted. This commit includes a module in src/test/modules with functions to manipulate the slots (which is not otherwise possible in SQL code) in order to enable testing, and a new test in src/test/recovery to ensure that the behavior is as expected. Author: Craig Ringer Reviewed-By: Oleksii Kliukin, Andres Freund, Petr Jelínek --- src/backend/access/transam/xlogreader.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src/backend/access/transam/xlogreader.c') diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c index 018fdf3d34e..b67da2ee925 100644 --- a/src/backend/access/transam/xlogreader.c +++ b/src/backend/access/transam/xlogreader.c @@ -118,6 +118,11 @@ XLogReaderAllocate(XLogPageReadCB pagereadfunc, void *private_data) return NULL; } +#ifndef FRONTEND + /* Will be loaded on first read */ + state->timelineHistory = NIL; +#endif + return state; } @@ -137,6 +142,10 @@ XLogReaderFree(XLogReaderState *state) pfree(state->errormsg_buf); if (state->readRecordBuf) pfree(state->readRecordBuf); +#ifndef FRONTEND + if (state->timelineHistory) + list_free_deep(state->timelineHistory); +#endif pfree(state->readBuf); pfree(state); } -- cgit v1.2.3