On Tue, Mar 2, 2010 at 10:52 PM, Fujii Masao <masao.fu...@gmail.com> wrote:
>> It's not clear what it should return, a TLI corresponding the filename
>> of the WAL segment the record was replayed from, so that you can use
>> pg_xlogfile_name() to find out the filename of the WAL segment being
>> replayed, or the accurate TLI of the record being replayed. I'm leaning
>> towards the latter, it feels more correct and accurate, but you could
>> argue for the former too. In any case, it needs to be well-defined.
>
> I agree with you that the latter is more correct and accurate. The simple
> fix is updating the lastPageTLI with the CheckPoint->ThisTimeLineID when
> replaying the shutdown checkpoint record. Though we might need to use new
> variable to keep the last applied timeline instead of the lastPageTLI.
Here is the revised patch. I used new local variable instead of lastPageTLI
to track the tli of last applied record. It is updated with the tli of the
log page header when reading the page, and with the tli of the checkpoint
record when replaying the checkpoint shutdown record that changes the tli.
So pg_last_xlog_replay_location() can return the accurate tli of the last
applied record.
Regards,
--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 13199,13204 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
--- 13199,13208 ----
This is usually the desired behavior for managing transaction log archiving
behavior, since the preceding file is the last one that currently
needs to be archived.
+ These functions also accept as a parameter the string that consists of timeline and
+ location, separated by a slash. In this case a transaction log file name is computed
+ by using the given timeline. On the other hand, if timeline is not supplied, the
+ current timeline is used for the computation.
</para>
<para>
***************
*** 13245,13257 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
<literal><function>pg_last_xlog_receive_location</function>()</literal>
</entry>
<entry><type>text</type></entry>
! <entry>Get last transaction log location received and synced to disk during
! streaming recovery. If streaming recovery is still in progress
this will increase monotonically. If streaming recovery has completed
then this value will remain static at the value of the last WAL record
received and synced to disk during that recovery. When the server has
been started without a streaming recovery then the return value will be
! InvalidXLogRecPtr (0/0).
</entry>
</row>
<row>
--- 13249,13263 ----
<literal><function>pg_last_xlog_receive_location</function>()</literal>
</entry>
<entry><type>text</type></entry>
! <entry>Get timeline and location of last transaction log received and synced
! to disk during streaming recovery. The return string is separated by a slash,
! the first value indicates the timeline and the other the location.
! If streaming recovery is still in progress
this will increase monotonically. If streaming recovery has completed
then this value will remain static at the value of the last WAL record
received and synced to disk during that recovery. When the server has
been started without a streaming recovery then the return value will be
! <literal>0/0/0</>.
</entry>
</row>
<row>
***************
*** 13259,13270 **** postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
<literal><function>pg_last_xlog_replay_location</function>()</literal>
</entry>
<entry><type>text</type></entry>
! <entry>Get last transaction log location replayed during recovery.
If recovery is still in progress this will increase monotonically.
If recovery has completed then this value will remain static at
the value of the last WAL record applied during that recovery.
When the server has been started normally without a recovery
! then the return value will be InvalidXLogRecPtr (0/0).
</entry>
</row>
</tbody>
--- 13265,13278 ----
<literal><function>pg_last_xlog_replay_location</function>()</literal>
</entry>
<entry><type>text</type></entry>
! <entry>Get timeline and location of last transaction log replayed during
! recovery. The return string is separated by a slash, the first value
! indicates the timeline and the other the location.
If recovery is still in progress this will increase monotonically.
If recovery has completed then this value will remain static at
the value of the last WAL record applied during that recovery.
When the server has been started normally without a recovery
! then the return value will be <literal>0/0/0</>.
</entry>
</row>
</tbody>
*** a/src/backend/access/transam/xlog.c
--- b/src/backend/access/transam/xlog.c
***************
*** 392,397 **** typedef struct XLogCtlData
--- 392,399 ----
TimestampTz recoveryLastXTime;
/* end+1 of the last record replayed */
XLogRecPtr recoveryLastRecPtr;
+ /* tli of last record replayed */
+ TimeLineID recoveryLastTLI;
slock_t info_lck; /* locks shared variables shown above */
} XLogCtlData;
***************
*** 471,476 **** static uint32 readRecordBufSize = 0;
--- 473,479 ----
static XLogRecPtr ReadRecPtr; /* start of last record read */
static XLogRecPtr EndRecPtr; /* end+1 of last record read */
static TimeLineID lastPageTLI = 0;
+ static TimeLineID lastRecTLI = 0; /* tli of last record read */
static XLogRecPtr minRecoveryPoint; /* local copy of
* ControlFile->minRecoveryPoint */
***************
*** 3943,3949 **** ValidXLOGHeader(XLogPageHeader hdr, int emode)
readId, readSeg, readOff)));
return false;
}
! lastPageTLI = hdr->xlp_tli;
return true;
}
--- 3946,3952 ----
readId, readSeg, readOff)));
return false;
}
! lastRecTLI = lastPageTLI = hdr->xlp_tli;
return true;
}
***************
*** 5782,5791 **** StartupXLOG(void)
/* use volatile pointer to prevent code rearrangement */
volatile XLogCtlData *xlogctl = XLogCtl;
! /* initialize shared replayEndRecPtr and recoveryLastRecPtr */
SpinLockAcquire(&xlogctl->info_lck);
xlogctl->replayEndRecPtr = ReadRecPtr;
xlogctl->recoveryLastRecPtr = ReadRecPtr;
SpinLockRelease(&xlogctl->info_lck);
InRedo = true;
--- 5785,5801 ----
/* use volatile pointer to prevent code rearrangement */
volatile XLogCtlData *xlogctl = XLogCtl;
! /*
! * initialize shared replayEndRecPtr, recoveryLastRecPtr and
! * recoveryLastTLI. Actually, the latter two variables don't need to
! * be initialized here since they are expected to be updated at least
! * once until read only connections will have read them. But just in
! * case.
! */
SpinLockAcquire(&xlogctl->info_lck);
xlogctl->replayEndRecPtr = ReadRecPtr;
xlogctl->recoveryLastRecPtr = ReadRecPtr;
+ xlogctl->recoveryLastTLI = lastRecTLI;
SpinLockRelease(&xlogctl->info_lck);
InRedo = true;
***************
*** 5913,5923 **** StartupXLOG(void)
error_context_stack = errcontext.previous;
/*
! * Update shared recoveryLastRecPtr after this record has been
! * replayed.
*/
SpinLockAcquire(&xlogctl->info_lck);
xlogctl->recoveryLastRecPtr = EndRecPtr;
SpinLockRelease(&xlogctl->info_lck);
LastRec = ReadRecPtr;
--- 5923,5934 ----
error_context_stack = errcontext.previous;
/*
! * Update shared recoveryLastRecPtr and recoveryLastTLI
! * after this record has been replayed.
*/
SpinLockAcquire(&xlogctl->info_lck);
xlogctl->recoveryLastRecPtr = EndRecPtr;
+ xlogctl->recoveryLastTLI = lastRecTLI;
SpinLockRelease(&xlogctl->info_lck);
LastRec = ReadRecPtr;
***************
*** 7479,7484 **** xlog_redo(XLogRecPtr lsn, XLogRecord *record)
--- 7490,7496 ----
/* Following WAL records should be run with new TLI */
ThisTimeLineID = checkPoint.ThisTimeLineID;
}
+ lastRecTLI = ThisTimeLineID;
RecoveryRestartPoint(&checkPoint);
}
***************
*** 8274,8280 **** pg_current_xlog_insert_location(PG_FUNCTION_ARGS)
}
/*
! * Report the last WAL receive location (same format as pg_start_backup etc)
*
* This is useful for determining how much of WAL is guaranteed to be received
* and synced to disk by walreceiver.
--- 8286,8292 ----
}
/*
! * Report the last WAL receive tli and location
*
* This is useful for determining how much of WAL is guaranteed to be received
* and synced to disk by walreceiver.
***************
*** 8287,8299 **** pg_last_xlog_receive_location(PG_FUNCTION_ARGS)
recptr = GetWalRcvWriteRecPtr();
! snprintf(location, sizeof(location), "%X/%X",
recptr.xlogid, recptr.xrecoff);
PG_RETURN_TEXT_P(cstring_to_text(location));
}
/*
! * Report the last WAL replay location (same format as pg_start_backup etc)
*
* This is useful for determining how much of WAL is visible to read-only
* connections during recovery.
--- 8299,8312 ----
recptr = GetWalRcvWriteRecPtr();
! snprintf(location, sizeof(location), "%X/%X/%X",
! XLogRecPtrIsInvalid(recptr) ? 0 : GetRecoveryTargetTLI(),
recptr.xlogid, recptr.xrecoff);
PG_RETURN_TEXT_P(cstring_to_text(location));
}
/*
! * Report the last WAL replay tli and location
*
* This is useful for determining how much of WAL is visible to read-only
* connections during recovery.
***************
*** 8303,8317 **** pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
{
/* use volatile pointer to prevent code rearrangement */
volatile XLogCtlData *xlogctl = XLogCtl;
XLogRecPtr recptr;
char location[MAXFNAMELEN];
SpinLockAcquire(&xlogctl->info_lck);
recptr = xlogctl->recoveryLastRecPtr;
SpinLockRelease(&xlogctl->info_lck);
! snprintf(location, sizeof(location), "%X/%X",
! recptr.xlogid, recptr.xrecoff);
PG_RETURN_TEXT_P(cstring_to_text(location));
}
--- 8316,8332 ----
{
/* use volatile pointer to prevent code rearrangement */
volatile XLogCtlData *xlogctl = XLogCtl;
+ TimeLineID tli;
XLogRecPtr recptr;
char location[MAXFNAMELEN];
SpinLockAcquire(&xlogctl->info_lck);
+ tli = xlogctl->recoveryLastTLI;
recptr = xlogctl->recoveryLastRecPtr;
SpinLockRelease(&xlogctl->info_lck);
! snprintf(location, sizeof(location), "%X/%X/%X",
! tli, recptr.xlogid, recptr.xrecoff);
PG_RETURN_TEXT_P(cstring_to_text(location));
}
***************
*** 8319,8324 **** pg_last_xlog_replay_location(PG_FUNCTION_ARGS)
--- 8334,8343 ----
* Compute an xlog file name and decimal byte offset given a WAL location,
* such as is returned by pg_stop_backup() or pg_xlog_switch().
*
+ * Also use the tli for the computation if it's given with a location,
+ * such as is returned by pg_last_xlog_receive_location() or
+ * pg_last_xlog_replay_location().
+ *
* Note that a location exactly at a segment boundary is taken to be in
* the previous segment. This is usually the right thing, since the
* expected usage is to determine which xlog file(s) are ready to archive.
***************
*** 8328,8338 **** pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
--- 8347,8359 ----
{
text *location = PG_GETARG_TEXT_P(0);
char *locationstr;
+ unsigned int utli;
unsigned int uxlogid;
unsigned int uxrecoff;
uint32 xlogid;
uint32 xlogseg;
uint32 xrecoff;
+ TimeLineID tli = ThisTimeLineID;
XLogRecPtr locationpoint;
char xlogfilename[MAXFNAMELEN];
Datum values[2];
***************
*** 8346,8352 **** pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
*/
locationstr = text_to_cstring(location);
! if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse transaction log location \"%s\"",
--- 8367,8375 ----
*/
locationstr = text_to_cstring(location);
! if (sscanf(locationstr, "%X/%X/%X", &utli, &uxlogid, &uxrecoff) == 3)
! tli = (TimeLineID) utli;
! else if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse transaction log location \"%s\"",
***************
*** 8371,8377 **** pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
* xlogfilename
*/
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
! XLogFileName(xlogfilename, ThisTimeLineID, xlogid, xlogseg);
values[0] = CStringGetTextDatum(xlogfilename);
isnull[0] = false;
--- 8394,8400 ----
* xlogfilename
*/
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
! XLogFileName(xlogfilename, tli, xlogid, xlogseg);
values[0] = CStringGetTextDatum(xlogfilename);
isnull[0] = false;
***************
*** 8397,8418 **** pg_xlogfile_name_offset(PG_FUNCTION_ARGS)
/*
* Compute an xlog file name given a WAL location,
* such as is returned by pg_stop_backup() or pg_xlog_switch().
*/
Datum
pg_xlogfile_name(PG_FUNCTION_ARGS)
{
text *location = PG_GETARG_TEXT_P(0);
char *locationstr;
unsigned int uxlogid;
unsigned int uxrecoff;
uint32 xlogid;
uint32 xlogseg;
XLogRecPtr locationpoint;
char xlogfilename[MAXFNAMELEN];
locationstr = text_to_cstring(location);
! if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse transaction log location \"%s\"",
--- 8420,8449 ----
/*
* Compute an xlog file name given a WAL location,
* such as is returned by pg_stop_backup() or pg_xlog_switch().
+ *
+ * Also use the tli for the computation if it's given with a location,
+ * such as is returned by pg_last_xlog_receive_location() or
+ * pg_last_xlog_replay_location().
*/
Datum
pg_xlogfile_name(PG_FUNCTION_ARGS)
{
text *location = PG_GETARG_TEXT_P(0);
char *locationstr;
+ unsigned int utli;
unsigned int uxlogid;
unsigned int uxrecoff;
uint32 xlogid;
uint32 xlogseg;
+ TimeLineID tli = ThisTimeLineID;
XLogRecPtr locationpoint;
char xlogfilename[MAXFNAMELEN];
locationstr = text_to_cstring(location);
! if (sscanf(locationstr, "%X/%X/%X", &utli, &uxlogid, &uxrecoff) == 3)
! tli = (TimeLineID) utli;
! else if (sscanf(locationstr, "%X/%X", &uxlogid, &uxrecoff) != 2)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse transaction log location \"%s\"",
***************
*** 8422,8428 **** pg_xlogfile_name(PG_FUNCTION_ARGS)
locationpoint.xrecoff = uxrecoff;
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
! XLogFileName(xlogfilename, ThisTimeLineID, xlogid, xlogseg);
PG_RETURN_TEXT_P(cstring_to_text(xlogfilename));
}
--- 8453,8459 ----
locationpoint.xrecoff = uxrecoff;
XLByteToPrevSeg(locationpoint, xlogid, xlogseg);
! XLogFileName(xlogfilename, tli, xlogid, xlogseg);
PG_RETURN_TEXT_P(cstring_to_text(xlogfilename));
}
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