What does it mean by XLOG_BACKUP_RECORD?
Hi,
While reading source codes I found the following comment in xlog.c.
/*
* Have we passed our safe starting point? Note that minRecoveryPoint is
* known to be incorrectly set if ControlFile->backupEndRequired, until
* the XLOG_BACKUP_RECORD arrives to advise us of the correct
* minRecoveryPoint. All we know prior to that is that we're not
* consistent yet.
*/
if (!reachedConsistency && !ControlFile->backupEndRequired &&
minRecoveryPoint <= lastReplayedEndRecPtr &&
XLogRecPtrIsInvalid(ControlFile->backupStartPoint))
What does XLOG_BACKUP_RECORED means by? I could not find such XLOG info value.
Does it mean XLOG_BACKUP_END?
Regards,
--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
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On Thu, Jun 29, 2017 at 10:28 AM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
While reading source codes I found the following comment in xlog.c.
/*
* Have we passed our safe starting point? Note that minRecoveryPoint is
* known to be incorrectly set if ControlFile->backupEndRequired, until
* the XLOG_BACKUP_RECORD arrives to advise us of the correct
* minRecoveryPoint. All we know prior to that is that we're not
* consistent yet.
*/
if (!reachedConsistency && !ControlFile->backupEndRequired &&
minRecoveryPoint <= lastReplayedEndRecPtr &&
XLogRecPtrIsInvalid(ControlFile->backupStartPoint))What does XLOG_BACKUP_RECORED means by? I could not find such XLOG info value.
Does it mean XLOG_BACKUP_END?
This comment is a thinko, it refers to XLOG_BACKUP_END. This comment
block could be reworded a bit, it looks cleaner to me to say
"ControlFile->backupEndRequired is false" instead of just referring to
the variable itself. Worse, the current comment implies that
minRecoveryPoint is incorrectly set if it is true. Bleh.
--
Michael
Attachments:
xlog-comment-fix.patchapplication/octet-stream; name=xlog-comment-fix.patchDownload
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 0a6314a642..afbd6d536a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7817,8 +7817,8 @@ CheckRecoveryConsistency(void)
/*
* Have we passed our safe starting point? Note that minRecoveryPoint is
- * known to be incorrectly set if ControlFile->backupEndRequired, until
- * the XLOG_BACKUP_RECORD arrives to advise us of the correct
+ * known to be incorrectly set if ControlFile->backupEndRequired is false,
+ * until the XLOG_BACKUP_END record arrives to advise us of the correct
* minRecoveryPoint. All we know prior to that is that we're not
* consistent yet.
*/
On Thu, Jun 29, 2017 at 10:49 AM, Michael Paquier
<michael.paquier@gmail.com> wrote:
On Thu, Jun 29, 2017 at 10:28 AM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
While reading source codes I found the following comment in xlog.c.
/*
* Have we passed our safe starting point? Note that minRecoveryPoint is
* known to be incorrectly set if ControlFile->backupEndRequired, until
* the XLOG_BACKUP_RECORD arrives to advise us of the correct
* minRecoveryPoint. All we know prior to that is that we're not
* consistent yet.
*/
if (!reachedConsistency && !ControlFile->backupEndRequired &&
minRecoveryPoint <= lastReplayedEndRecPtr &&
XLogRecPtrIsInvalid(ControlFile->backupStartPoint))What does XLOG_BACKUP_RECORED means by? I could not find such XLOG info value.
Does it mean XLOG_BACKUP_END?This comment is a thinko, it refers to XLOG_BACKUP_END. This comment
block could be reworded a bit, it looks cleaner to me to say
"ControlFile->backupEndRequired is false" instead of just referring to
the variable itself.
Thanks, I agree to use XLOG_BACKUP_END instead.
Worse, the current comment implies that
minRecoveryPoint is incorrectly set if it is true. Bleh.
Looking at the condition, we use minRecoveryPoint only when
ControlFile->backupEndRequired is *false*. So I guess that it means
that minRecoveryPoint is incorrectly set if
ControlFile->backupEndReuired is true. Am I missing something?
Regards,
--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
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On 6/29/17 06:09, Masahiko Sawada wrote:
Thanks, I agree to use XLOG_BACKUP_END instead.
Worse, the current comment implies that
minRecoveryPoint is incorrectly set if it is true. Bleh.Looking at the condition, we use minRecoveryPoint only when
ControlFile->backupEndRequired is *false*. So I guess that it means
that minRecoveryPoint is incorrectly set if
ControlFile->backupEndReuired is true. Am I missing something?
I agree with you that the logic in the comment is correct. I've
committed just the symbol change.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
On Sat, Dec 9, 2017 at 1:25 AM, Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
On 6/29/17 06:09, Masahiko Sawada wrote:
Thanks, I agree to use XLOG_BACKUP_END instead.
Worse, the current comment implies that
minRecoveryPoint is incorrectly set if it is true. Bleh.Looking at the condition, we use minRecoveryPoint only when
ControlFile->backupEndRequired is *false*. So I guess that it means
that minRecoveryPoint is incorrectly set if
ControlFile->backupEndReuired is true. Am I missing something?I agree with you that the logic in the comment is correct. I've
committed just the symbol change.
Thank you for picking up an old thread and committing it!
Regards,
--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center