From 6b34e5563849edc12896bf5754e8fe7b88012697 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Thu, 3 Dec 2015 22:21:16 -0500
Subject: [PATCH] pg_rewind: Don't error if the two clusters are already on the
same timeline
This previously resulted in an error and a nonzero exit status, but
after discussion this should rather be a noop with a zero exit status.
---
src/bin/pg_rewind/pg_rewind.c | 59 +++++++++++++-----------
src/bin/pg_rewind/t/005_same_timeline.pl | 14 ++++++
2 files changed, 46 insertions(+), 27 deletions(-)
create mode 100644 src/bin/pg_rewind/t/005_same_timeline.pl
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 1ab82f07cb4..635a3ab96f1 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -216,41 +216,46 @@ main(int argc, char **argv)
* do.
*/
if (ControlFile_target.checkPointCopy.ThisTimeLineID == ControlFile_source.checkPointCopy.ThisTimeLineID)
- pg_fatal("source and target cluster are on the same timeline\n");
-
- findCommonAncestorTimeline(&divergerec, &lastcommontliIndex);
- printf(_("servers diverged at WAL position %X/%X on timeline %u\n"),
- (uint32) (divergerec >> 32), (uint32) divergerec,
- targetHistory[lastcommontliIndex].tli);
-
- /*
- * Check for the possibility that the target is in fact a direct ancestor
- * of the source. In that case, there is no divergent history in the
- * target that needs rewinding.
- */
- if (ControlFile_target.checkPoint >= divergerec)
{
- rewind_needed = true;
+ printf(_("source and target cluster are on the same timeline\n"));
+ rewind_needed = false;
}
else
{
- XLogRecPtr chkptendrec;
-
- /* Read the checkpoint record on the target to see where it ends. */
- chkptendrec = readOneRecord(datadir_target,
- ControlFile_target.checkPoint,
- targetNentries - 1);
+ findCommonAncestorTimeline(&divergerec, &lastcommontliIndex);
+ printf(_("servers diverged at WAL position %X/%X on timeline %u\n"),
+ (uint32) (divergerec >> 32), (uint32) divergerec,
+ targetHistory[lastcommontliIndex].tli);
/*
- * If the histories diverged exactly at the end of the shutdown
- * checkpoint record on the target, there are no WAL records in the
- * target that don't belong in the source's history, and no rewind is
- * needed.
+ * Check for the possibility that the target is in fact a direct ancestor
+ * of the source. In that case, there is no divergent history in the
+ * target that needs rewinding.
*/
- if (chkptendrec == divergerec)
- rewind_needed = false;
- else
+ if (ControlFile_target.checkPoint >= divergerec)
+ {
rewind_needed = true;
+ }
+ else
+ {
+ XLogRecPtr chkptendrec;
+
+ /* Read the checkpoint record on the target to see where it ends. */
+ chkptendrec = readOneRecord(datadir_target,
+ ControlFile_target.checkPoint,
+ targetNentries - 1);
+
+ /*
+ * If the histories diverged exactly at the end of the shutdown
+ * checkpoint record on the target, there are no WAL records in the
+ * target that don't belong in the source's history, and no rewind is
+ * needed.
+ */
+ if (chkptendrec == divergerec)
+ rewind_needed = false;
+ else
+ rewind_needed = true;
+ }
}
if (!rewind_needed)
diff --git a/src/bin/pg_rewind/t/005_same_timeline.pl b/src/bin/pg_rewind/t/005_same_timeline.pl
new file mode 100644
index 00000000000..8ca442671cd
--- /dev/null
+++ b/src/bin/pg_rewind/t/005_same_timeline.pl
@@ -0,0 +1,14 @@
+use strict;
+use warnings;
+use TestLib;
+use Test::More tests => 1;
+
+use RewindTest;
+
+# Test that running pg_rewind if the two clusters are on the same
+# timeline runs successfully.
+
+RewindTest::setup_cluster();
+RewindTest::start_master();
+RewindTest::create_standby();
+RewindTest::run_pg_rewind('local');
--
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