Re: [PERFORM] Query Core Dumping

Thanks, Tom.  Forwarded from pgsl-performance.

Segmentation Fault - core dumped

===================================
> pollsys(0x080475B8, 1, 0x00000000, 0x00000000) = 1
> recv(4, " i t z _ l i s a @ h o t".., 16005, 0) = 8192
> brk(0x095FBCF0) = 0
> brk(0x095FDCF0) = 0
> pollsys(0x080475B8, 1, 0x00000000, 0x00000000) = 1
> recv(4, "\0\0\007 U L L - N S W\0".., 16278, 0) = 3404
> brk(0x095FDCF0) = 0
> brk(0x095FFCF0) = 0
> Incurred fault #6, FLTBOUNDS %pc = 0x080BF4EF
> siginfo: SIGSEGV SEGV_MAPERR addr=0x00000168
> Received signal #11, SIGSEGV [default]
> siginfo: SIGSEGV SEGV_MAPERR addr=0x00000168
>
===================================

From gdb:

#0 0x080bf4ef in Perl_sv_vcatpvfn ()
#1 0x080bdb30 in Perl_sv_vsetpvfn ()
#2 0x080a1363 in Perl_vmess ()
#3 0x080a1d06 in Perl_vwarn ()
#4 0x080a1fde in Perl_warn ()
#5 0xfe7f9d58 in pg_warn () from
/usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8/i86pc-solaris/auto/DBD/Pg/Pg.so
#6 0xfe7c704e in defaultNoticeReceiver () from /usr/local/lib/libpq.so.4
#7 0xfe7cf0bc in pqGetErrorNotice3 () from /usr/local/lib/libpq.so.4
#8 0xfe7cf67f in pqParseInput3 () from /usr/local/lib/libpq.so.4
#9 0xfe7c8398 in parseInput () from /usr/local/lib/libpq.so.4
#10 0xfe7c8c63 in PQgetResult () from /usr/local/lib/libpq.so.4
#11 0xfe7c8d5b in PQexecFinish () from /usr/local/lib/libpq.so.4
#12 0xfe7fdcc1 in dbd_st_execute () from
/usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8/i86pc-solaris/auto/DBD/Pg/Pg.so
#13 0xfe7f512f in XS_DBD_Pg_db_selectall_arrayref () from
/usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8/i86pc-solaris/auto/DBD/Pg/Pg.so
#14 0xfecfb301 in XS_DBI_dispatch () from
/usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8/i86pc-solaris/auto/DBI/DBI.so
#15 0x080b3609 in Perl_pp_entersub ()
#16 0x080ad365 in Perl_runops_standard ()
#17 0x08068814 in S_run_body ()
#18 0x0806852b in perl_run ()
#19 0x08065ae0 in main ()

> perl -V
Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
 Platform:
   osname=solaris, osvers=2.10, archname=i86pc-solaris
   uname='sunos katana7 5.10 generic_118855-15 i86pc i386 i86pc '
   config_args='-de -A prepend:libswanted=db
-Dlocincpth=/usr/local/include/db_185
-Dloclibpth=/usr/local/lib/db_185 -Dcc=gcc
-Dprefix=/usr/local/stow/perl-5.8.8'
   hint=recommended, useposix=true, d_sigaction=define
   usethreads=undef use5005threads=undef useithreads=undef
usemultiplicity=undef
   useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
   use64bitint=undef use64bitall=undef uselongdouble=undef
   usemymalloc=n, bincompat5005=undef
 Compiler:
   cc='gcc', ccflags ='-fno-strict-aliasing -pipe
-Wdeclaration-after-statement -I/usr/local/include/db_185
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -DPERL_USE_SAFE_PUTENV
-DPERL_USE_SAFE_PUTENV -DPERL_USE_SAFE_PUTENV -DPERL_USE_SAFE_PUTENV
-DPERL_USE_SAFE_PUTENV',
   optimize='-O',
   cppflags='-fno-strict-aliasing -pipe -Wdeclaration-after-statement
-I/usr/local/include/db_185'
   ccversion='', gccversion='3.4.3
(csl-sol210-3_4-branch+sol_rpath)', gccosandvers='solaris2.10'
   intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
   d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
   ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
lseeksize=8
   alignbytes=4, prototype=define
 Linker and Libraries:
   ld='gcc', ldflags =' -L/usr/local/lib/db_185 '
   libpth=/usr/local/lib/db_185 /usr/lib /usr/ccs/lib /usr/local/lib
   libs=-lsocket -lnsl -ldl -lm -lc
   perllibs=-lsocket -lnsl -ldl -lm -lc
   libc=/lib/libc.so, so=so, useshrplib=false, libperl=libperl.a
   gnulibc_version=''
 Dynamic Linking:
   dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
   cccdlflags='-fPIC', lddlflags='-G -L/usr/local/lib/db_185'


Characteristics of this binary (from libperl):
 Compile-time options: PERL_MALLOC_WRAP PERL_USE_SAFE_PUTENV
                       USE_LARGE_FILES USE_PERLIO
 Built under solaris
 Compiled at Aug 29 2006 21:33:23
 @INC:
   /usr/local/stow/perl-5.8.8/lib/5.8.8/i86pc-solaris
   /usr/local/stow/perl-5.8.8/lib/5.8.8
   /usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8/i86pc-solaris
   /usr/local/stow/perl-5.8.8/lib/site_perl/5.8.8
   /usr/local/stow/perl-5.8.8/lib/site_perl
   .
>

Sam

On Wed, Feb 9, 2011 at 10:28 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Sam Stearns <samtstearns@gmail.com> writes:
>> I have a SELECT query that runs no problem standalone but when running
>> within a perl script it intermittently core dumps.  Random, no pattern
>> to the timing of the core dumps.  The perl script processes the rows
>> from the query, if the rows satisfy  a condition then the perl script
>> adds the rows to another table.  When the script works it runs for
>> about a minute.  If the script fails, it runs for about 5 minutes and
>> core dumps.  The core dump is in the perl error handling routines.  We
>> suspect the bug is related to how the perl postgres libraries interact
>> with postgres.
>
> Can you get a stack trace from one of the core dumps?
>
> Also, exactly which perl version are you using, and with what build
> options?  ("perl -V" output would be a good answer here.)
>
> BTW, this seems pretty off-topic for pgsql-performance.
>
>                        regards, tom lane
>