Horton

Re: libpq debug log

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

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From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: iwata.aya@fujitsu.com
Cc: alvherre@alvh.no-ip.org, tgl@sss.pgh.pa.us, tsunakawa.takay@fujitsu.com, k.jamison@fujitsu.com, pgsql-hackers@lists.postgresql.org
Date: 2021-04-02T05:40:09Z
Lists: pgsql-hackers 
At Fri, 2 Apr 2021 02:56:44 +0000, "iwata.aya@fujitsu.com" <iwata.aya@fujitsu.com> wrote in 
> Hi Alvaro san
> 
> Thank you for your fix of trace log code.
> 
> > From: 'alvherre@alvh.no-ip.org' <alvherre@alvh.no-ip.org>
> > Sent: Friday, April 2, 2021 11:30 AM
> ...
> > It still didn't fix it!  Drongo is now reporting a difference in the expected trace --
> > and the differences all seem to be message lengths.
> > Now that is pretty mysterious, because the messages themselves are printed
> > identically.  Perl's output is pretty unhelpful, but I wrote them to a file and diffed
> > manually; it's attached.
>
> Do ErrorResponse and NoticeResponse vary from test to test ...?
> If so, it seemed difficult to make the trace logs available for regression test. 
> I will also investigate the cause of this issue.

The redacted fields, F, L and R contained source file, souce line and
source function respectively. It is reasonable guess that the
difference comes from them but I'm not sure how they make a difference
of 50 bytes in length...

Anyway if the length is wrong, we should get an error after emitting
the log line.

>	if (logCursor - 1 != length)
>		fprintf(conn->Pfdebug,
>				"mismatched message length: consumed %d, expected %d\n",
>				logCursor - 1, length);

So, the cheapest measure for regression test would be just making the
length field, while regress is true...

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

Commits

  1. Rename PQtraceSetFlags() to PQsetTraceFlags().

  2. Suppress length of Notice/Error msgs in PQtrace regress mode

  3. Strip file names reported in error messages on Windows, too.

  4. Fix setvbuf()-induced crash in libpq_pipeline

  5. libpq_pipeline: Must strdup(optarg) to avoid crash

  6. Remove setvbuf() call from PQtrace()

  7. Initialize conn->Pfdebug to NULL when creating a connection

  8. Disable force_parallel_mode in libpq_pipeline

  9. libpq_pipeline: add PQtrace() support and tests

  10. Improve PQtrace() output format

  11. Re-simplify management of inStart in pqParseInput3's subroutines.