Don't forget to flush XLOG_PARAMETER_CHANGE record.

MasaoFujii · MasaoFujii · commit a8603f0da866 · 2014-03-26T02:14:08.000+09:00
Backpatch to 9.0 where XLOG_PARAMETER_CHANGE record was instroduced.
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
@@ -8446,6 +8446,7 @@ XLogReportParameters(void)
 		{
 			XLogRecData rdata;
 			xl_parameter_change xlrec;
+			XLogRecPtr	recptr;
 
 			xlrec.MaxConnections = MaxConnections;
 			xlrec.max_prepared_xacts = max_prepared_xacts;
@@ -8457,7 +8458,8 @@ XLogReportParameters(void)
 			rdata.len = sizeof(xlrec);
 			rdata.next = NULL;
 
-			XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);
+			recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);
+			XLogFlush(recptr);
 		}
 
 		ControlFile->MaxConnections = MaxConnections;

Original file line number	Diff line number	Diff line change
`@@ -8446,6 +8446,7 @@ XLogReportParameters(void)`
`8446`	`8446`	`{`
`8447`	`8447`	`XLogRecData rdata;`
`8448`	`8448`	`xl_parameter_change xlrec;`
	`8449`	`+ XLogRecPtr recptr;`
`8449`	`8450`
`8450`	`8451`	`xlrec.MaxConnections = MaxConnections;`
`8451`	`8452`	`xlrec.max_prepared_xacts = max_prepared_xacts;`
`@@ -8457,7 +8458,8 @@ XLogReportParameters(void)`
`8457`	`8458`	`rdata.len = sizeof(xlrec);`
`8458`	`8459`	`rdata.next = NULL;`
`8459`	`8460`
`8460`		`- XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`8461`	`+ recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`8462`	`+ XLogFlush(recptr);`
`8461`	`8463`	`}`
`8462`	`8464`
`8463`	`8465`	`ControlFile->MaxConnections = MaxConnections;`