walreceiver_notify_archive_soon_v2.patch

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 24165ab03e..6c407045dd 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7576,6 +7576,34 @@ StartupXLOG(void)
 				/* Handle interrupt signals of startup process */
 				HandleStartupProcInterrupts();
 
+				/*
+				 * Create an archive notification file of a streamed WAL
+				 * segment if it includes an XLOG_SWITCH record and its
+				 * notification file has not been created yet. This is
+				 * necessary to handle the corner case that walreceiver may
+				 * fail to create such notification file if it exits after it
+				 * receives XLOG_SWITCH record but while it's receiving the
+				 * remaining bytes in the segment. Without this handling, WAL
+				 * archiving of the segment will be delayed until subsequent
+				 * checkpoint creates its notification file when removing it
+				 * even though it can be archived soon.
+				 */
+				if (readSource == XLOG_FROM_STREAM &&
+					record->xl_rmid == RM_XLOG_ID &&
+					(record->xl_info & ~XLR_INFO_MASK) == XLOG_SWITCH)
+				{
+					char		xlogfilename[MAXFNAMELEN];
+
+					XLogFileName(xlogfilename, curFileTLI, readSegNo, wal_segment_size);
+					if (!XLogArchiveIsReadyOrDone(xlogfilename))
+					{
+						if (XLogArchivingAlways())
+							XLogArchiveNotify(xlogfilename, true);
+						else
+							XLogArchiveForceDone(xlogfilename);
+					}
+				}
+
 				/*
 				 * Pause WAL replay, if requested by a hot-standby session via
 				 * SetRecoveryPause().
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index 60de3be92c..5b07eef3aa 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -125,6 +125,7 @@ static void WalRcvDie(int code, Datum arg);
 static void XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len);
 static void XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr);
 static void XLogWalRcvFlush(bool dying);
+static void XLogWalRcvClose(XLogRecPtr recptr);
 static void XLogWalRcvSendReply(bool force, bool requestReply);
 static void XLogWalRcvSendHSFeedback(bool immed);
 static void ProcessWalSndrMessage(XLogRecPtr walEnd, TimestampTz sendTime);
@@ -883,42 +884,11 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 	{
 		int			segbytes;
 
-		if (recvFile < 0 || !XLByteInSeg(recptr, recvSegNo, wal_segment_size))
+		/* Close the current segment if it's completed */
+		XLogWalRcvClose(recptr);
+
+		if (recvFile < 0)
 		{
-			/*
-			 * fsync() and close current file before we switch to next one. We
-			 * would otherwise have to reopen this file to fsync it later
-			 */
-			if (recvFile >= 0)
-			{
-				char		xlogfname[MAXFNAMELEN];
-
-				XLogWalRcvFlush(false);
-
-				XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
-
-				/*
-				 * XLOG segment files will be re-read by recovery in startup
-				 * process soon, so we don't advise the OS to release cache
-				 * pages associated with the file like XLogFileClose() does.
-				 */
-				if (close(recvFile) != 0)
-					ereport(PANIC,
-							(errcode_for_file_access(),
-							 errmsg("could not close log segment %s: %m",
-									xlogfname)));
-
-				/*
-				 * Create .done file forcibly to prevent the streamed segment
-				 * from being archived later.
-				 */
-				if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS)
-					XLogArchiveForceDone(xlogfname);
-				else
-					XLogArchiveNotify(xlogfname, true);
-			}
-			recvFile = -1;
-
 			/* Create/use new log file */
 			XLByteToSeg(recptr, recvSegNo, wal_segment_size);
 			recvFile = XLogFileInit(recvSegNo);
@@ -967,6 +937,14 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 
 	/* Update shared-memory status */
 	pg_atomic_write_u64(&WalRcv->writtenUpto, LogstreamResult.Write);
+
+	/*
+	 * Close the current segment if it's fully written up in the last cycle of
+	 * the loop, to create its archive notification file soon. Otherwise WAL
+	 * archiving of the segment will be delayed until any data in the next
+	 * segment is received and written.
+	 */
+	XLogWalRcvClose(recptr);
 }
 
 /*
@@ -1020,6 +998,53 @@ XLogWalRcvFlush(bool dying)
 	}
 }
 
+/*
+ * Close the current segment if it's completed.
+ *
+ * Flush the segment to disk before closing it. Otherwise we have to
+ * reopen and fsync it later.
+ *
+ * Create an archive notification file since the segment is known completed.
+ */
+static void
+XLogWalRcvClose(XLogRecPtr recptr)
+{
+	if (recvFile >= 0 && !XLByteInSeg(recptr, recvSegNo, wal_segment_size))
+	{
+		char		xlogfname[MAXFNAMELEN];
+
+		/*
+		 * fsync() and close current file before we switch to next one. We
+		 * would otherwise have to reopen this file to fsync it later
+		 */
+		XLogWalRcvFlush(false);
+
+		XLogFileName(xlogfname, recvFileTLI, recvSegNo, wal_segment_size);
+
+		/*
+		 * XLOG segment files will be re-read by recovery in startup process
+		 * soon, so we don't advise the OS to release cache pages associated
+		 * with the file like XLogFileClose() does.
+		 */
+		if (close(recvFile) != 0)
+			ereport(PANIC,
+					(errcode_for_file_access(),
+					 errmsg("could not close log segment %s: %m",
+							xlogfname)));
+
+		/*
+		 * Create .done file forcibly to prevent the streamed segment from
+		 * being archived later.
+		 */
+		if (XLogArchiveMode != ARCHIVE_MODE_ALWAYS)
+			XLogArchiveForceDone(xlogfname);
+		else
+			XLogArchiveNotify(xlogfname, true);
+
+		recvFile = -1;
+	}
+}
+
 /*
  * Send reply message to primary, indicating our current WAL locations, oldest
  * xmin and the current time.