Don't forget to flush XLOG_PARAMETER_CHANGE record.

MasaoFujii · MasaoFujii · commit b12f99478757 · 2014-03-26T02:13:51.000+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
@@ -7821,6 +7821,7 @@ XLogReportParameters(void)
 		{
 			XLogRecData rdata;
 			xl_parameter_change xlrec;
+			XLogRecPtr	recptr;
 
 			xlrec.MaxConnections = MaxConnections;
 			xlrec.max_prepared_xacts = max_prepared_xacts;
@@ -7832,7 +7833,8 @@ 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
`@@ -7821,6 +7821,7 @@ XLogReportParameters(void)`
`7821`	`7821`	`{`
`7822`	`7822`	`XLogRecData rdata;`
`7823`	`7823`	`xl_parameter_change xlrec;`
	`7824`	`+ XLogRecPtr recptr;`
`7824`	`7825`
`7825`	`7826`	`xlrec.MaxConnections = MaxConnections;`
`7826`	`7827`	`xlrec.max_prepared_xacts = max_prepared_xacts;`
`@@ -7832,7 +7833,8 @@ XLogReportParameters(void)`
`7832`	`7833`	`rdata.len = sizeof(xlrec);`
`7833`	`7834`	`rdata.next = NULL;`
`7834`	`7835`
`7835`		`- XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`7836`	`+ recptr = XLogInsert(RM_XLOG_ID, XLOG_PARAMETER_CHANGE, &rdata);`
	`7837`	`+ XLogFlush(recptr);`
`7836`	`7838`	`}`
`7837`	`7839`
`7838`	`7840`	`ControlFile->MaxConnections = MaxConnections;`