On 2017-09-16 13:27:05 -0700, Andres Freund wrote:
> > This does not seem like a problem that justifies a system-wide change
> > that's much more delicate than you thought.
>
> We need one more initialization call during crash-restart - that doesn't
> seem particularly hard a fix.
FWIW, attached is that simple fix. Not quite ready for commit - needs
more comments, thoughts and a glass of wine less to commit.
I'll try to come up with a tap test that tests crash restarts tomorrow -
not sure if there's a decent way to trigger one on windows without
writing a C function. Will play around with that tomorrow.
- Andres
>From 6728a5f4620270c1a116e295f316536861a317f4 Mon Sep 17 00:00:00 2001
From: Andres Freund <and...@anarazel.de>
Date: Sun, 17 Sep 2017 01:00:39 -0700
Subject: [PATCH] Preliminary fix for crash-restart.
---
src/backend/access/transam/xlog.c | 4 ++--
src/backend/postmaster/postmaster.c | 6 +++++-
src/backend/tcop/postgres.c | 2 +-
src/include/access/xlog.h | 2 +-
4 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index b8f648927a..b475e3fb6b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4808,9 +4808,9 @@ check_wal_buffers(int *newval, void **extra, GucSource source)
* memory. XLOGShemInit() will then copy it to shared memory later.
*/
void
-LocalProcessControlFile(void)
+LocalProcessControlFile(bool reset)
{
- Assert(ControlFile == NULL);
+ Assert(reset || ControlFile == NULL);
ControlFile = palloc(sizeof(ControlFileData));
ReadControlFile();
}
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index e4f8f597c6..7ccf8dbd9d 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -951,7 +951,7 @@ PostmasterMain(int argc, char *argv[])
CreateDataDirLockFile(true);
/* read control file (error checking and contains config) */
- LocalProcessControlFile();
+ LocalProcessControlFile(false);
/*
* Initialize SSL library, if specified.
@@ -3829,6 +3829,10 @@ PostmasterStateMachine(void)
ResetBackgroundWorkerCrashTimes();
shmem_exit(1);
+
+ /* re-read control file into local memory */
+ LocalProcessControlFile(true);
+
reset_shared(PostPortNumber);
StartupPID = StartupDataBase();
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 46b662266b..dfd52b3c87 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3718,7 +3718,7 @@ PostgresMain(int argc, char *argv[],
CreateDataDirLockFile(false);
/* read control file (error checking and contains config ) */
- LocalProcessControlFile();
+ LocalProcessControlFile(false);
/* Initialize MaxBackends (if under postmaster, was done already) */
InitializeMaxBackends();
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index e0635ab4e6..7213af0e81 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -261,7 +261,7 @@ extern XLogRecPtr GetFakeLSNForUnloggedRel(void);
extern Size XLOGShmemSize(void);
extern void XLOGShmemInit(void);
extern void BootStrapXLOG(void);
-extern void LocalProcessControlFile(void);
+extern void LocalProcessControlFile(bool reset);
extern void StartupXLOG(void);
extern void ShutdownXLOG(int code, Datum arg);
extern void InitXLOGAccess(void);
--
2.14.1.536.g6867272d5b.dirty
--
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