Re: postmaster core ( finally I have it ) [ vacuum pg_rewrite ] - Mailing list pgsql-hackers

From: "Tom Lane" <tgl@sss.pgh.pa.us>
> "Mendola Gaetano" <mendola@bigfoot.com> writes:
> > From: "Tom Lane" <tgl@sss.pgh.pa.us>
> >> I suspect some form of
> >> data corruption in the pg_rewrite row(s) for this table.  Do you
> >> see any misbehavior when you do
> >>
> >> select * from pg_rewrite where ev_class =
'v_psl_package_info'::regclass
>
> > All seems good.
>
> I really don't see any other explanation for a crash in that routine
> than problems with the pg_rewrite data.
>
> Do you get this any time you try to do something with the
> v_psl_package_info view, or is it a once-in-a-while problem?
> If the latter, I wonder whether it could be an issue with a
> flaky disk sector ...

Is once-in-a-while but always at 00 minutes. This select is performed each
20 minutes and
the core happen always at 00 never at 20 and never at 40!

I have scheduled also a vacuumdb -z each 15 minutes so only at
00 these are running together.

I had another core at 21:00 today and this is the log of the vacuum
( there was that error just during the pg_rewrite vacuum!):

INFO:  --Relation pg_catalog.pg_description--
INFO:  Pages 12: Changed 0, Empty 0; Tup 1390: Vac 0, Keep 0, UnUsed 1.       Total CPU 0.00s/0.00u sec elapsed 0.20
sec.
INFO:  --Relation pg_toast.pg_toast_16416--
INFO:  Pages 0: Changed 0, Empty 0; Tup 0: Vac 0, Keep 0, UnUsed 0.       Total CPU 0.00s/0.00u sec elapsed 0.01 sec.
INFO:  Analyzing pg_catalog.pg_description
INFO:  --Relation pg_catalog.pg_group--
INFO:  Pages 1: Changed 0, Empty 0; Tup 3: Vac 0, Keep 0, UnUsed 9.       Total CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO:  --Relation pg_toast.pg_toast_1261--
INFO:  Pages 0: Changed 0, Empty 0; Tup 0: Vac 0, Keep 0, UnUsed 0.       Total CPU 0.00s/0.00u sec elapsed 0.01 sec.
INFO:  Analyzing pg_catalog.pg_group
INFO:  --Relation pg_catalog.pg_proc--
INFO:  Pages 111: Changed 0, Empty 0; Tup 1822: Vac 0, Keep 0, UnUsed 272.       Total CPU 0.02s/0.00u sec elapsed 0.29
sec.
INFO:  --Relation pg_toast.pg_toast_1255--
INFO:  Pages 0: Changed 0, Empty 0; Tup 0: Vac 0, Keep 0, UnUsed 0.       Total CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO:  Analyzing pg_catalog.pg_proc
INFO:  --Relation pg_catalog.pg_rewrite--
INFO:  Pages 47: Changed 0, Empty 0; Tup 231: Vac 0, Keep 0, UnUsed 74.       Total CPU 0.00s/0.00u sec elapsed 0.07
sec.
INFO:  --Relation pg_toast.pg_toast_16410--
INFO:  Pages 22: Changed 0, Empty 0; Tup 77: Vac 0, Keep 0, UnUsed 33.       Total CPU 0.00s/0.00u sec elapsed 0.03
sec.
INFO:  Analyzing pg_catalog.pg_rewrite
WARNING:  Message from PostgreSQL backend:       The Postmaster has informed me that some other backend       died
abnormallyand possibly corrupted shared memory.       I have rolled back the current transaction and am       going to
terminateyour database system connection and exit.       Please reconnect to the database system and repeat your
query.
server closed the connection unexpectedly       This probably means the server terminated abnormally       before or
whileprocessing the request.
 
connection to server was lost
vacuumdb: vacuum  empdb failed


I think we are near the solution now.


Thank you
Gaetano