This is new version of the patch.
I replaced GetStandbyFlushRecPtr with GetXLogReplayRecPtr to
check progress of checkpoint following Fujii's sugestion.
The first one is for 9.2dev, and the second is 9.1.3 backported version.
===
By the way, I took a close look around there,
> I agree with it basically. But I've get confused to look into
> GetStandbyFlushRecPtr().
>
> | if (XLByteLT(receivePtr, replayPtr))
> | return XLByteLT(replayPtr, restorePtr) ? restorePtr : replayPtr;
> | else
> | return XLByteLT(receivePtr, restorePtr) ? restorePtr : receivePtr;
- receivePtr seems always updated just after syncing received xlog.
- replayPtr is updated just BEFORE xlog_redo operation, and
- restorePtr is updated AFTER xlog_redo().
- And, replayPtr seems not exceeds receivePtr.
These seems quite reasonable. These conditions make following
conditional expression.
restorePtr <= replayPtr <= receivePtr
But XLByteLT(recievePtr, replayPtr) this should not return true
under the condition above.. Something wrong in my assumption?
Anyway, I understand here that you say the location returned by
GetXLogReplayRecPtr() is always flushed.
--
Kyotaro Horiguchi
NTT Open Source Software Center
== My e-mail address has been changed since Apr. 1, 2012.
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index c9473f7..c2fafbf 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -491,8 +491,8 @@ CheckpointerMain(void)
* Initialize checkpointer-private variables used during checkpoint.
*/
ckpt_active = true;
- if (!do_restartpoint)
- ckpt_start_recptr = GetInsertRecPtr();
+ ckpt_start_recptr =
+ do_restartpoint ? GetXLogReplayRecPtr(NULL) : GetInsertRecPtr();
ckpt_start_time = now;
ckpt_cached_elapsed = 0;
@@ -731,28 +731,30 @@ IsCheckpointOnSchedule(double progress)
return false;
/*
- * Check progress against WAL segments written and checkpoint_segments.
+ * Check progress against WAL segments written, or replayed for
+ * hot standby, and checkpoint_segments.
*
* We compare the current WAL insert location against the location
- * computed before calling CreateCheckPoint. The code in XLogInsert that
- * actually triggers a checkpoint when checkpoint_segments is exceeded
- * compares against RedoRecptr, so this is not completely accurate.
- * However, it's good enough for our purposes, we're only calculating an
- * estimate anyway.
+ * computed before calling CreateCheckPoint. The code in
+ * XLogInsert that actually triggers a checkpoint when
+ * checkpoint_segments is exceeded compares against RedoRecPtr.
+ * Similarly, we consult WAL replay location instead on hot
+ * standbys and XLogPageRead compares it aganst RedoRecPtr, too.
+ * Altough these are not completely accurate, it's good enough for
+ * our purposes, we're only calculating an estimate anyway.
*/
- if (!RecoveryInProgress())
+
+ recptr =
+ RecoveryInProgress() ? GetXLogReplayRecPtr(NULL) : GetInsertRecPtr();
+ elapsed_xlogs =
+ (((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
+ ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
+ CheckPointSegments;
+
+ if (progress < elapsed_xlogs)
{
- recptr = GetInsertRecPtr();
- elapsed_xlogs =
- (((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
- ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
- CheckPointSegments;
-
- if (progress < elapsed_xlogs)
- {
- ckpt_cached_elapsed = elapsed_xlogs;
- return false;
- }
+ ckpt_cached_elapsed = elapsed_xlogs;
+ return false;
}
/*
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index 5643ec8..a272866 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -56,6 +56,7 @@
#include "pgstat.h"
#include "postmaster/bgwriter.h"
#include "replication/syncrep.h"
+#include "replication/walreceiver.h"
#include "storage/bufmgr.h"
#include "storage/fd.h"
#include "storage/ipc.h"
@@ -489,8 +490,8 @@ BackgroundWriterMain(void)
* Initialize bgwriter-private variables used during checkpoint.
*/
ckpt_active = true;
- if (!do_restartpoint)
- ckpt_start_recptr = GetInsertRecPtr();
+ ckpt_start_recptr = do_restartpoint ?
+ GetXLogReplayRecPtr() : GetInsertRecPtr();
ckpt_start_time = now;
ckpt_cached_elapsed = 0;
@@ -764,30 +765,32 @@ IsCheckpointOnSchedule(double progress)
return false;
/*
- * Check progress against WAL segments written and checkpoint_segments.
+ * Check progress against WAL segments written, or replayed for
+ * hot standby, and checkpoint_segments.
*
* We compare the current WAL insert location against the location
- * computed before calling CreateCheckPoint. The code in XLogInsert that
- * actually triggers a checkpoint when checkpoint_segments is exceeded
- * compares against RedoRecptr, so this is not completely accurate.
- * However, it's good enough for our purposes, we're only calculating an
- * estimate anyway.
+ * computed before calling CreateCheckPoint. The code in
+ * XLogInsert that actually triggers a checkpoint when
+ * checkpoint_segments is exceeded compares against RedoRecPtr.
+ * Similarly, we consult WAL replay location instead on hot
+ * standbys and XLogPageRead compares it aganst RedoRecPtr, too.
+ * Altough these are not completely accurate, it's good enough for
+ * our purposes, we're only calculating an estimate anyway.
*/
- if (!RecoveryInProgress())
+
+ recptr =
+ RecoveryInProgress() ? GetXLogReplayRecPtr() : GetInsertRecPtr();
+ elapsed_xlogs =
+ (((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
+ ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
+ CheckPointSegments;
+
+ if (progress < elapsed_xlogs)
{
- recptr = GetInsertRecPtr();
- elapsed_xlogs =
- (((double) (int32) (recptr.xlogid - ckpt_start_recptr.xlogid)) * XLogSegsPerFile +
- ((double) recptr.xrecoff - (double) ckpt_start_recptr.xrecoff) / XLogSegSize) /
- CheckPointSegments;
-
- if (progress < elapsed_xlogs)
- {
- ckpt_cached_elapsed = elapsed_xlogs;
- return false;
- }
+ ckpt_cached_elapsed = elapsed_xlogs;
+ return false;
}
-
+
/*
* Check progress against time elapsed and checkpoint_timeout.
*/
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
