Don't forget to flush XLOG_PARAMETER_CHANGE record.

MasaoFujii · MasaoFujii · commit 49638868f81f · 2014-03-26T02:12:39.000+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
@@ -8904,6 +8904,7 @@ XLogReportParameters(void)
 		{
 			XLogRecData rdata;
 			xl_parameter_change xlrec;
+			XLogRecPtr	recptr;
 
 			xlrec.MaxConnections = MaxConnections;
 			xlrec.max_worker_processes = max_worker_processes;
@@ -8917,7 +8918,8 @@ 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
`@@ -8904,6 +8904,7 @@ XLogReportParameters(void)`
`8904`	`8904`	`{`
`8905`	`8905`	`XLogRecData rdata;`
`8906`	`8906`	`xl_parameter_change xlrec;`
	`8907`	`+ XLogRecPtr recptr;`
`8907`	`8908`
`8908`	`8909`	`xlrec.MaxConnections = MaxConnections;`
`8909`	`8910`	`xlrec.max_worker_processes = max_worker_processes;`
`@@ -8917,7 +8918,8 @@ XLogReportParameters(void)`
`8917`	`8918`	`rdata.len = sizeof(xlrec);`
`8918`	`8919`	`rdata.next = NULL;`
`8919`	`8920`
`8920`		`- XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`8921`	`+ recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`8922`	`+ XLogFlush(recptr);`
`8921`	`8923`	`}`
`8922`	`8924`
`8923`	`8925`	`ControlFile->MaxConnections = MaxConnections;`