[PATCH] Log PostgreSQL version number on startup

From 0a482552d26488ec5ce8e4d7bad12bf25ba44c8b Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Wed, 16 Jan 2019 17:32:01 +0100
Subject: [PATCH] postmaster: Start syslogger earlier

XXX
---
 src/backend/postmaster/postmaster.c | 120 ++++++++++++++--------------
 1 file changed, 60 insertions(+), 60 deletions(-)

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index a707d4d465..36efd908bb 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -992,6 +992,66 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	InitializeMaxBackends();
 
+	/*
+	 * Initialize pipe (or process handle on Windows) that allows children to
+	 * wake up from sleep on postmaster death.
+	 */
+	InitPostmasterDeathWatchHandle();
+
+	/*
+	 * Forcibly remove the files signaling a standby promotion request.
+	 * Otherwise, the existence of those files triggers a promotion too early,
+	 * whether a user wants that or not.
+	 *
+	 * This removal of files is usually unnecessary because they can exist
+	 * only during a few moments during a standby promotion. However there is
+	 * a race condition: if pg_ctl promote is executed and creates the files
+	 * during a promotion, the files can stay around even after the server is
+	 * brought up to new master. Then, if new standby starts by using the
+	 * backup taken from that master, the files can exist at the server
+	 * startup and should be removed in order to avoid an unexpected
+	 * promotion.
+	 *
+	 * Note that promotion signal files need to be removed before the startup
+	 * process is invoked. Because, after that, they can be used by
+	 * postmaster's SIGUSR1 signal handler.
+	 */
+	RemovePromoteSignalFiles();
+
+	/* Do the same for logrotate signal file */
+	RemoveLogrotateSignalFiles();
+
+	/* Remove any outdated file holding the current log filenames. */
+	if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
+		ereport(LOG,
+				(errcode_for_file_access(),
+				 errmsg("could not remove file \"%s\": %m",
+						LOG_METAINFO_DATAFILE)));
+
+	/*
+	 * If enabled, start up syslogger collection subprocess
+	 */
+	SysLoggerPID = SysLogger_Start();
+
+	/*
+	 * Reset whereToSendOutput from DestDebug (its starting state) to
+	 * DestNone. This stops ereport from sending log messages to stderr unless
+	 * Log_destination permits.  We don't do this until the postmaster is
+	 * fully launched, since startup failures may as well be reported to
+	 * stderr.
+	 *
+	 * If we are in fact disabling logging to stderr, first emit a log message
+	 * saying so, to provide a breadcrumb trail for users who may not remember
+	 * that their logging is configured to go somewhere else.
+	 */
+	if (!(Log_destination & LOG_DESTINATION_STDERR))
+		ereport(LOG,
+				(errmsg("ending log output to stderr"),
+				 errhint("Future log output will go to log destination \"%s\".",
+						 Log_destination_string)));
+
+	whereToSendOutput = DestNone;
+
 	/*
 	 * Establish input sockets.
 	 *
@@ -1183,12 +1243,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	set_stack_base();
 
-	/*
-	 * Initialize pipe (or process handle on Windows) that allows children to
-	 * wake up from sleep on postmaster death.
-	 */
-	InitPostmasterDeathWatchHandle();
-
 #ifdef WIN32
 
 	/*
@@ -1242,60 +1296,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	RemovePgTempFiles();
 
-	/*
-	 * Forcibly remove the files signaling a standby promotion request.
-	 * Otherwise, the existence of those files triggers a promotion too early,
-	 * whether a user wants that or not.
-	 *
-	 * This removal of files is usually unnecessary because they can exist
-	 * only during a few moments during a standby promotion. However there is
-	 * a race condition: if pg_ctl promote is executed and creates the files
-	 * during a promotion, the files can stay around even after the server is
-	 * brought up to new master. Then, if new standby starts by using the
-	 * backup taken from that master, the files can exist at the server
-	 * startup and should be removed in order to avoid an unexpected
-	 * promotion.
-	 *
-	 * Note that promotion signal files need to be removed before the startup
-	 * process is invoked. Because, after that, they can be used by
-	 * postmaster's SIGUSR1 signal handler.
-	 */
-	RemovePromoteSignalFiles();
-
-	/* Do the same for logrotate signal file */
-	RemoveLogrotateSignalFiles();
-
-	/* Remove any outdated file holding the current log filenames. */
-	if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
-		ereport(LOG,
-				(errcode_for_file_access(),
-				 errmsg("could not remove file \"%s\": %m",
-						LOG_METAINFO_DATAFILE)));
-
-	/*
-	 * If enabled, start up syslogger collection subprocess
-	 */
-	SysLoggerPID = SysLogger_Start();
-
-	/*
-	 * Reset whereToSendOutput from DestDebug (its starting state) to
-	 * DestNone. This stops ereport from sending log messages to stderr unless
-	 * Log_destination permits.  We don't do this until the postmaster is
-	 * fully launched, since startup failures may as well be reported to
-	 * stderr.
-	 *
-	 * If we are in fact disabling logging to stderr, first emit a log message
-	 * saying so, to provide a breadcrumb trail for users who may not remember
-	 * that their logging is configured to go somewhere else.
-	 */
-	if (!(Log_destination & LOG_DESTINATION_STDERR))
-		ereport(LOG,
-				(errmsg("ending log output to stderr"),
-				 errhint("Future log output will go to log destination \"%s\".",
-						 Log_destination_string)));
-
-	whereToSendOutput = DestNone;
-
 	/*
 	 * Initialize stats collection subsystem (this does NOT start the
 	 * collector process!)
-- 
2.20.1

From d876be48c3f5beca5da6cb19e804ab0307409f80 Mon Sep 17 00:00:00 2001
From: Christoph Berg <christoph.berg@credativ.de>
Date: Tue, 29 Jan 2019 16:26:04 +0100
Subject: [PATCH 1/2] postmaster: Start syslogger earlier

---
 src/backend/postmaster/postmaster.c | 120 ++++++++++++++--------------
 1 file changed, 60 insertions(+), 60 deletions(-)

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 3052bbbc21..119c01d745 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -992,6 +992,66 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	InitializeMaxBackends();
 
+	/*
+	 * Initialize pipe (or process handle on Windows) that allows children to
+	 * wake up from sleep on postmaster death.
+	 */
+	InitPostmasterDeathWatchHandle();
+
+	/*
+	 * Forcibly remove the files signaling a standby promotion request.
+	 * Otherwise, the existence of those files triggers a promotion too early,
+	 * whether a user wants that or not.
+	 *
+	 * This removal of files is usually unnecessary because they can exist
+	 * only during a few moments during a standby promotion. However there is
+	 * a race condition: if pg_ctl promote is executed and creates the files
+	 * during a promotion, the files can stay around even after the server is
+	 * brought up to new master. Then, if new standby starts by using the
+	 * backup taken from that master, the files can exist at the server
+	 * startup and should be removed in order to avoid an unexpected
+	 * promotion.
+	 *
+	 * Note that promotion signal files need to be removed before the startup
+	 * process is invoked. Because, after that, they can be used by
+	 * postmaster's SIGUSR1 signal handler.
+	 */
+	RemovePromoteSignalFiles();
+
+	/* Do the same for logrotate signal file */
+	RemoveLogrotateSignalFiles();
+
+	/* Remove any outdated file holding the current log filenames. */
+	if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
+		ereport(LOG,
+				(errcode_for_file_access(),
+				 errmsg("could not remove file \"%s\": %m",
+						LOG_METAINFO_DATAFILE)));
+
+	/*
+	 * If enabled, start up syslogger collection subprocess
+	 */
+	SysLoggerPID = SysLogger_Start();
+
+	/*
+	 * Reset whereToSendOutput from DestDebug (its starting state) to
+	 * DestNone. This stops ereport from sending log messages to stderr unless
+	 * Log_destination permits.  We don't do this until the postmaster is
+	 * fully launched, since startup failures may as well be reported to
+	 * stderr.
+	 *
+	 * If we are in fact disabling logging to stderr, first emit a log message
+	 * saying so, to provide a breadcrumb trail for users who may not remember
+	 * that their logging is configured to go somewhere else.
+	 */
+	if (!(Log_destination & LOG_DESTINATION_STDERR))
+		ereport(LOG,
+				(errmsg("ending log output to stderr"),
+				 errhint("Future log output will go to log destination \"%s\".",
+						 Log_destination_string)));
+
+	whereToSendOutput = DestNone;
+
 	/*
 	 * Establish input sockets.
 	 *
@@ -1183,12 +1243,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	set_stack_base();
 
-	/*
-	 * Initialize pipe (or process handle on Windows) that allows children to
-	 * wake up from sleep on postmaster death.
-	 */
-	InitPostmasterDeathWatchHandle();
-
 #ifdef WIN32
 
 	/*
@@ -1242,60 +1296,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	RemovePgTempFiles();
 
-	/*
-	 * Forcibly remove the files signaling a standby promotion request.
-	 * Otherwise, the existence of those files triggers a promotion too early,
-	 * whether a user wants that or not.
-	 *
-	 * This removal of files is usually unnecessary because they can exist
-	 * only during a few moments during a standby promotion. However there is
-	 * a race condition: if pg_ctl promote is executed and creates the files
-	 * during a promotion, the files can stay around even after the server is
-	 * brought up to new master. Then, if new standby starts by using the
-	 * backup taken from that master, the files can exist at the server
-	 * startup and should be removed in order to avoid an unexpected
-	 * promotion.
-	 *
-	 * Note that promotion signal files need to be removed before the startup
-	 * process is invoked. Because, after that, they can be used by
-	 * postmaster's SIGUSR1 signal handler.
-	 */
-	RemovePromoteSignalFiles();
-
-	/* Do the same for logrotate signal file */
-	RemoveLogrotateSignalFiles();
-
-	/* Remove any outdated file holding the current log filenames. */
-	if (unlink(LOG_METAINFO_DATAFILE) < 0 && errno != ENOENT)
-		ereport(LOG,
-				(errcode_for_file_access(),
-				 errmsg("could not remove file \"%s\": %m",
-						LOG_METAINFO_DATAFILE)));
-
-	/*
-	 * If enabled, start up syslogger collection subprocess
-	 */
-	SysLoggerPID = SysLogger_Start();
-
-	/*
-	 * Reset whereToSendOutput from DestDebug (its starting state) to
-	 * DestNone. This stops ereport from sending log messages to stderr unless
-	 * Log_destination permits.  We don't do this until the postmaster is
-	 * fully launched, since startup failures may as well be reported to
-	 * stderr.
-	 *
-	 * If we are in fact disabling logging to stderr, first emit a log message
-	 * saying so, to provide a breadcrumb trail for users who may not remember
-	 * that their logging is configured to go somewhere else.
-	 */
-	if (!(Log_destination & LOG_DESTINATION_STDERR))
-		ereport(LOG,
-				(errmsg("ending log output to stderr"),
-				 errhint("Future log output will go to log destination \"%s\".",
-						 Log_destination_string)));
-
-	whereToSendOutput = DestNone;
-
 	/*
 	 * Initialize stats collection subsystem (this does NOT start the
 	 * collector process!)
-- 
2.20.1

From 8e8fa64cdefdbebfecb431b766def198ac9ad673 Mon Sep 17 00:00:00 2001
From: Christoph Berg <christoph.berg@credativ.de>
Date: Wed, 21 Nov 2018 15:43:34 +0100
Subject: [PATCH 2/2] Log PostgreSQL version number on startup

Logging the PostgreSQL version on startup is useful for two reasons:
There is a clear marker in the log file that a new postmaster is
beginning, and it's useful for tracking the server version across
startup while upgrading.
---
 src/backend/postmaster/postmaster.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 119c01d745..40a0222220 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -1052,6 +1052,10 @@ PostmasterMain(int argc, char *argv[])
 
 	whereToSendOutput = DestNone;
 
+	/* Report server startup in log */
+	ereport(LOG,
+			(errmsg("starting %s", PG_VERSION_STR)));
+
 	/*
 	 * Establish input sockets.
 	 *
-- 
2.20.1