On Tue, Sep 27, 2022 at 8:31 AM Kyotaro Horiguchi
<horikyota....@gmail.com> wrote:
>
> If all error-emitting site knows the LSN, we don't need the context
> message. But *I* would like that the additional message looks like
> "while reading record at LSN %X/%X" or slightly shorter version of
> it. Because the targetRecPtr is the beginning of the current reading
> record, not the LSN for the segment and offset. It may point to past
> segments.
I think we could just say "LSN %X/%X, offset %u", because the overall
context whether it's being read or written is implicit with the other
part of the message.
Please see the attached v1 patch.
--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
From b19aa25a0d1f2ce85abe0c2081c0e7ede256e329 Mon Sep 17 00:00:00 2001
From: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Date: Thu, 29 Sep 2022 13:29:44 +0000
Subject: [PATCH v1] Add LSN along with offset to error messages reported for
WAL file read/write/validate header failures
---
src/backend/access/transam/xlog.c | 8 ++++++--
src/backend/access/transam/xlogreader.c | 16 +++++++++++-----
src/backend/access/transam/xlogrecovery.c | 13 ++++++++-----
src/backend/access/transam/xlogutils.c | 10 ++++++----
src/include/access/xlogreader.h | 1 +
5 files changed, 32 insertions(+), 16 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 8e15256db8..a495bbac85 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2218,6 +2218,7 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
{
char xlogfname[MAXFNAMELEN];
int save_errno;
+ XLogRecPtr lsn;
if (errno == EINTR)
continue;
@@ -2226,11 +2227,14 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
XLogFileName(xlogfname, tli, openLogSegNo,
wal_segment_size);
errno = save_errno;
+ XLogSegNoOffsetToRecPtr(openLogSegNo, startoffset,
+ wal_segment_size, lsn);
ereport(PANIC,
(errcode_for_file_access(),
errmsg("could not write to log file %s "
- "at offset %u, length %zu: %m",
- xlogfname, startoffset, nleft)));
+ "at offset %u, LSN %X/%X, length %zu: %m",
+ xlogfname, startoffset,
+ LSN_FORMAT_ARGS(lsn), nleft)));
}
nleft -= written;
from += written;
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index 5a8fe81f82..c3befc44ba 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -1229,9 +1229,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "invalid magic number %04X in WAL segment %s, offset %u",
+ "invalid magic number %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_magic,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1243,9 +1244,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "invalid info bits %04X in WAL segment %s, offset %u",
+ "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_info,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1284,9 +1286,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
/* hmm, first page of file doesn't have a long header? */
report_invalid_record(state,
- "invalid info bits %04X in WAL segment %s, offset %u",
+ "invalid info bits %04X in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_info,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1303,9 +1306,10 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "unexpected pageaddr %X/%X in WAL segment %s, offset %u",
+ "unexpected pageaddr %X/%X in WAL segment %s, LSN %X/%X, offset %u",
LSN_FORMAT_ARGS(hdr->xlp_pageaddr),
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1328,10 +1332,11 @@ XLogReaderValidatePageHeader(XLogReaderState *state, XLogRecPtr recptr,
XLogFileName(fname, state->seg.ws_tli, segno, state->segcxt.ws_segsize);
report_invalid_record(state,
- "out-of-sequence timeline ID %u (after %u) in WAL segment %s, offset %u",
+ "out-of-sequence timeline ID %u (after %u) in WAL segment %s, LSN %X/%X, offset %u",
hdr->xlp_tli,
state->latestPageTLI,
fname,
+ LSN_FORMAT_ARGS(recptr),
offset);
return false;
}
@@ -1556,6 +1561,7 @@ WALRead(XLogReaderState *state,
errinfo->wre_req = segbytes;
errinfo->wre_read = readbytes;
errinfo->wre_off = startoff;
+ errinfo->wre_lsn = recptr;
errinfo->wre_seg = state->seg;
return false;
}
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index cb07694aea..c6ffb29c05 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -3079,9 +3079,10 @@ ReadRecord(XLogPrefetcher *xlogprefetcher, int emode,
XLogFileName(fname, xlogreader->seg.ws_tli, segno,
wal_segment_size);
ereport(emode_for_corrupt_record(emode, xlogreader->EndRecPtr),
- (errmsg("unexpected timeline ID %u in WAL segment %s, offset %u",
+ (errmsg("unexpected timeline ID %u in WAL segment %s, LSN %X/%X, offset %u",
xlogreader->latestPageTLI,
fname,
+ LSN_FORMAT_ARGS(xlogreader->latestPagePtr),
offset)));
record = NULL;
}
@@ -3284,14 +3285,16 @@ retry:
errno = save_errno;
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode_for_file_access(),
- errmsg("could not read from WAL segment %s, offset %u: %m",
- fname, readOff)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: %m",
+ fname, LSN_FORMAT_ARGS(targetPagePtr),
+ readOff)));
}
else
ereport(emode_for_corrupt_record(emode, targetPagePtr + reqLen),
(errcode(ERRCODE_DATA_CORRUPTED),
- errmsg("could not read from WAL segment %s, offset %u: read %d of %zu",
- fname, readOff, r, (Size) XLOG_BLCKSZ)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %u: read %d of %zu",
+ fname, LSN_FORMAT_ARGS(targetPagePtr),
+ readOff, r, (Size) XLOG_BLCKSZ)));
goto next_record_is_invalid;
}
pgstat_report_wait_end();
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 563cba258d..9d171f2ad9 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -1051,15 +1051,17 @@ WALReadRaiseError(WALReadError *errinfo)
errno = errinfo->wre_errno;
ereport(ERROR,
(errcode_for_file_access(),
- errmsg("could not read from WAL segment %s, offset %d: %m",
- fname, errinfo->wre_off)));
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %d: %m",
+ fname, LSN_FORMAT_ARGS(errinfo->wre_lsn),
+ errinfo->wre_off)));
}
else if (errinfo->wre_read == 0)
{
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
- errmsg("could not read from WAL segment %s, offset %d: read %d of %d",
- fname, errinfo->wre_off, errinfo->wre_read,
+ errmsg("could not read from WAL segment %s, LSN %X/%X, offset %d: read %d of %d",
+ fname, LSN_FORMAT_ARGS(errinfo->wre_lsn),
+ errinfo->wre_off, errinfo->wre_read,
errinfo->wre_req)));
}
}
diff --git a/src/include/access/xlogreader.h b/src/include/access/xlogreader.h
index e87f91316a..1e47169b5a 100644
--- a/src/include/access/xlogreader.h
+++ b/src/include/access/xlogreader.h
@@ -386,6 +386,7 @@ typedef struct WALReadError
int wre_off; /* Offset we tried to read from. */
int wre_req; /* Bytes requested to be read. */
int wre_read; /* Bytes read by the last read(). */
+ XLogRecPtr wre_lsn; /* WAL LSN being read. */
WALOpenSegment wre_seg; /* Segment we tried to read from. */
} WALReadError;
--
2.34.1
