WAL receiver shouldn't try to send a reply when dying.

robertmhaas · robertmhaas · commit 3a087369c0ea · 2011-02-16T10:27:35.000-05:00
Per report from, and discussion with, Fujii Masao.
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
@@ -118,7 +118,7 @@ static void DisableWalRcvImmediateExit(void);
 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(void);
+static void XLogWalRcvFlush(bool dying);
 static void XLogWalRcvSendReply(void);
 
 /* Signal handlers */
@@ -319,7 +319,7 @@ WalReceiverMain(void)
 			 * If we've written some records, flush them to disk and let the
 			 * startup process know about them.
 			 */
-			XLogWalRcvFlush();
+			XLogWalRcvFlush(false);
 		}
 		else
 		{
@@ -342,7 +342,7 @@ WalRcvDie(int code, Datum arg)
 	volatile WalRcvData *walrcv = WalRcv;
 
 	/* Ensure that all WAL records received are flushed to disk */
-	XLogWalRcvFlush();
+	XLogWalRcvFlush(true);
 
 	SpinLockAcquire(&walrcv->mutex);
 	Assert(walrcv->walRcvState == WALRCV_RUNNING ||
@@ -461,7 +461,7 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 			 */
 			if (recvFile >= 0)
 			{
-				XLogWalRcvFlush();
+				XLogWalRcvFlush(false);
 
 				/*
 				 * XLOG segment files will be re-read by recovery in startup
@@ -531,9 +531,14 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 	}
 }
 
-/* Flush the log to disk */
+/*
+ * Flush the log to disk.
+ *
+ * If we're in the midst of dying, it's unwise to do anything that might throw
+ * an error, so we skip sending a reply in that case.
+ */
 static void
-XLogWalRcvFlush(void)
+XLogWalRcvFlush(bool dying)
 {
 	if (XLByteLT(LogstreamResult.Flush, LogstreamResult.Write))
 	{
@@ -565,7 +570,8 @@ XLogWalRcvFlush(void)
 		}
 
 		/* Also let the master know that we made some progress */
-		XLogWalRcvSendReply();
+		if (!dying)
+			XLogWalRcvSendReply();
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -118,7 +118,7 @@ static void DisableWalRcvImmediateExit(void);`
`118`	`118`	`static void WalRcvDie(int code, Datum arg);`
`119`	`119`	`static void XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len);`
`120`	`120`	`static void XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr);`
`121`		`-static void XLogWalRcvFlush(void);`
	`121`	`+static void XLogWalRcvFlush(bool dying);`
`122`	`122`	`static void XLogWalRcvSendReply(void);`
`123`	`123`
`124`	`124`	`/* Signal handlers */`
`@@ -319,7 +319,7 @@ WalReceiverMain(void)`
`319`	`319`	`* If we've written some records, flush them to disk and let the`
`320`	`320`	`* startup process know about them.`
`321`	`321`	`*/`
`322`		`- XLogWalRcvFlush();`
	`322`	`+ XLogWalRcvFlush(false);`
`323`	`323`	`}`
`324`	`324`	`else`
`325`	`325`	`{`
`@@ -342,7 +342,7 @@ WalRcvDie(int code, Datum arg)`
`342`	`342`	`volatile WalRcvData *walrcv = WalRcv;`
`343`	`343`
`344`	`344`	`/* Ensure that all WAL records received are flushed to disk */`
`345`		`- XLogWalRcvFlush();`
	`345`	`+ XLogWalRcvFlush(true);`
`346`	`346`
`347`	`347`	`SpinLockAcquire(&walrcv->mutex);`
`348`	`348`	`Assert(walrcv->walRcvState == WALRCV_RUNNING \|\|`
`@@ -461,7 +461,7 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)`
`461`	`461`	`*/`
`462`	`462`	`if (recvFile >= 0)`
`463`	`463`	`{`
`464`		`- XLogWalRcvFlush();`
	`464`	`+ XLogWalRcvFlush(false);`
`465`	`465`
`466`	`466`	`/*`
`467`	`467`	`* XLOG segment files will be re-read by recovery in startup`
`@@ -531,9 +531,14 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)`
`531`	`531`	`}`
`532`	`532`	`}`
`533`	`533`
`534`		`-/* Flush the log to disk */`
	`534`	`+/*`
	`535`	`+ * Flush the log to disk.`
	`536`	`+ *`
	`537`	`+ * If we're in the midst of dying, it's unwise to do anything that might throw`
	`538`	`+ * an error, so we skip sending a reply in that case.`
	`539`	`+ */`
`535`	`540`	`static void`
`536`		`-XLogWalRcvFlush(void)`
	`541`	`+XLogWalRcvFlush(bool dying)`
`537`	`542`	`{`
`538`	`543`	`if (XLByteLT(LogstreamResult.Flush, LogstreamResult.Write))`
`539`	`544`	`{`
`@@ -565,7 +570,8 @@ XLogWalRcvFlush(void)`
`565`	`570`	`}`
`566`	`571`
`567`	`572`	`/* Also let the master know that we made some progress */`
`568`		`- XLogWalRcvSendReply();`
	`573`	`+ if (!dying)`
	`574`	`+ XLogWalRcvSendReply();`
`569`	`575`	`}`
`570`	`576`	`}`
`571`	`577`