Re: Gerbil build farm failure

Now that we have backtrace, does anyone have a clue about the cause/fix?

---------------------------------------------------------------------------

Jim C. Nasby wrote:
> On Tue, Sep 20, 2005 at 01:17:10PM -0400, Bruce Momjian wrote:
> > I worked with Jim Nasby and we found this is the line that is failing on
> > Gerbil in the build farm during initdb: tqual.c, line 844 in 8.0.X
> >
> > if (HeapTupleHeaderGetCmin(tuple) >= snapshot->curcid)
> >
> > This particular line was last modified in 2002. However, this was a
> > file that was changed as part of the VACUUM tuple chain commit:
> >
> > revision 1.81.4.2
> > date: 2005/08/25 19:45:01; author: tgl; state: Exp; lines: +7 -4
> > Back-patch fixes for problems with VACUUM destroying t_ctid chains too soon,
> > and with insufficient paranoia in code that follows t_ctid links.
> > This patch covers the 8.0 branch.
> >
> > and the date of the commit to 8.0.X corresponds to the date that
> > failures started to happen:
> >
> > http://pgbuildfarm.org/cgi-bin/show_history.pl?nm=gerbil&br=REL8_0_STABLE
>
> BTW, I want to point out for others that when initdb dumps core trying
> to get a stack trace out of the initdb binary will probably be useless,
> because initdb is just calling other binaries. In this case we had
> sucess with the postgres binary. Had I know this I would have had this
> stack trace available a couple weeks ago. :(
>
> http://lnk.nu/developer.postgresql.org/3zx.c is the annotated version of
> tqual. As Bruce mentioned, the line referenced in the core file probably
> isn't the culprit. http://lnk.nu/pgbuildfarm.org/3zz.pl has the list of
> files that changed to break gerbil.
>
> Here's the output from gdb:
> #0 HeapTupleSatisfiesSnapshot (tuple=0xfe28fc78, snapshot=0xd7, buffer=295) at tqual.c:844
> 844 tqual.c: No such file or directory.
> in tqual.c
> (gdb) bt
> #0 HeapTupleSatisfiesSnapshot (tuple=0xfe28fc78, snapshot=0xd7, buffer=295) at tqual.c:844
> #1 0x0004bdd0 in heap_update ()
> #2 0x000ec4b0 in ExecutorRun (queryDesc=0x0, direction=-4198192, count=16) at execMain.c:1592
> (gdb)
>
> I'm in the process of trying to get this machine moved someplace where I
> could give a developer ssh access. That should hopefully happen by the
> end of the week.
> --
> Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
> Pervasive Software http://pervasive.com work: 512-231-6117
> vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend
>

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073