Обсуждение: Debugging initdb breakage
Hi,
So I'm beginning to work on the extension support for dump and restore,
and that begins with a new pg_extension catalog. I managed to break
initdb already, of course, but I'm fighting my way out — no luck with
gdb, it won't catch the Assert failure and show me a backtrace. I tried
"set follow-fork-mode child" in gdb, in different systems, to no avail.
Please find attached the detailed initdb.log and the very few items I
needed to obtain:
TRAP: FailedAssertion("!(reln->md_fd[forkNum] == ((void *)0))", File: "md.c", Line: 254)
child process was terminated by signal 6: Abort trap
How to have gdb help me? What's my error, that I guess is obvious? Where
do I read more now in order not to need too much assistance after that?
Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support
Вложения
On 10.10.2010 23:38, Dimitri Fontaine wrote:
> So I'm beginning to work on the extension support for dump and restore,
> and that begins with a new pg_extension catalog. I managed to break
> initdb already, of course, but I'm fighting my way out — no luck with
> gdb, it won't catch the Assert failure and show me a backtrace. I tried
> "set follow-fork-mode child" in gdb, in different systems, to no avail.
>
> Please find attached the detailed initdb.log and the very few items I
> needed to obtain:
>
> TRAP: FailedAssertion("!(reln->md_fd[forkNum] == ((void *)0))", File: "md.c", Line: 254)
> child process was terminated by signal 6: Abort trap
>
> How to have gdb help me? What's my error, that I guess is obvious? Where
> do I read more now in order not to need too much assistance after that?
At least on my system, assertion failure creates a core dump that you
can load in gdb. Make sure you use "ulimit -c unlimited" or similar.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com
Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
> How to have gdb help me? What's my error, that I guess is obvious?
Might have something to do with using the same OID for the catalog
and its index ...
regards, tom lane
Tom Lane <tgl@sss.pgh.pa.us> writes: > Might have something to do with using the same OID for the catalog > and its index ... Ahah, that's how obvious it was, thank you. I feel ashamed, but at the same time, thanks to your answer, it now feels like the week-end was a good preparatory step for opening this week. Back to producing cores (ulimit -c unlimited), -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support
Excerpts from Dimitri Fontaine's message of dom oct 10 17:38:01 -0300 2010: > Hi, > > So I'm beginning to work on the extension support for dump and restore, > and that begins with a new pg_extension catalog. I managed to break > initdb already, of course, but I'm fighting my way out — no luck with > gdb, it won't catch the Assert failure and show me a backtrace. I tried > "set follow-fork-mode child" in gdb, in different systems, to no avail. As a note, I've had luck finding bootstrap-time bugs by manually feeding the bootstrapping commands into bootstrap mode, with a leftover dir from "initdb --noclean". This has helped a few times that there has been no PANIC but just a FATAL or ERROR, for example. It's easy to attach GDB to such a backend. -- Álvaro Herrera <alvherre@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Alvaro Herrera <alvherre@commandprompt.com> writes: > As a note, I've had luck finding bootstrap-time bugs by manually feeding > the bootstrapping commands into bootstrap mode, with a leftover dir from > "initdb --noclean". This has helped a few times that there has been no > PANIC but just a FATAL or ERROR, for example. It's easy to attach GDB > to such a backend. Nice tip, thanks! -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support
On Tue, Oct 12, 2010 at 10:05:57PM +0200, Dimitri Fontaine wrote: > Alvaro Herrera <alvherre@commandprompt.com> writes: > > As a note, I've had luck finding bootstrap-time bugs by manually > > feeding the bootstrapping commands into bootstrap mode, with a > > leftover dir from "initdb --noclean". This has helped a few times > > that there has been no PANIC but just a FATAL or ERROR, for > > example. It's easy to attach GDB to such a backend. > > Nice tip, thanks! Where should we preserve this, other than the mailing list archives? Cheers, David. -- David Fetter <david@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate
David Fetter wrote: > Where should we preserve this, other than the mailing list archives? > http://wiki.postgresql.org/wiki/Getting_a_stack_trace_of_a_running_PostgreSQL_backend_on_Linux/BSD has most of the other trivia in this area, so I just added Alvaro's technique to the bottom of it with a quick intro to add some context. -- Greg Smith, 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD PostgreSQL Training, Services and Support www.2ndQuadrant.us