qpsmtpd processes in an infinite loop

Front page | perl.qpsmtpd | Postings from June 2005

qpsmtpd processes in an infinite loop

Thread Next

From:

Justin Erenkrantz

Date:

June 15, 2005 11:47

Subject:

qpsmtpd processes in an infinite loop

As I've mentioned before, we (apache.org) are seeing our qpsmtpd processes 
stuck in an infinite loop.  We're using qpsmtpd-forkserver.

At Ask's suggestion, I've placed in Carp::Confess lines - but the program 
isn't accepting signals when we reach this loop state.  At all other times, 
it'll respond to SIGUSR2 and print the perl stack trace.

I can't consistently reproduce this; but we get 5-10 perl processes a day 
that are eating up all of our CPU.

Any help is appreciated.  If you need/want coredumps, let me know.  I'm 
available on AIM if you want to help me debug this in real-time (email me 
for my AIM nick).  We have a collection of these processes SIGSTOPed so we 
can examine them.

Does anyone think upgrading to perl 5.8.7 help?

Thanks!  -- justin

gdb stack trace:

(gdb) where
#0  0x281040d2 in Perl_newSVpvn ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#1  0x280e9526 in Perl_magic_setsig ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#2  0x280e782b in Perl_mg_set ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#3  0x280f241d in Perl_pp_sassign ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#4  0x280f1fad in Perl_runops_standard ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#5  0x280a0c26 in S_run_body ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#6  0x280a08b1 in perl_run ()
   from /usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
#7  0x08049040 in main ()

pstack output:

57376: /usr/local/bin/perl5.8.6
----------------- thread -1 (running) -----------------
 0x281040d2 Perl_newSVpvn (80543b0, 4, bfbfec40, 280e9306, 808cad8, 50) + 1e
 0x280e9526 Perl_magic_setsig (808cb5c, 8098b38, bfbfecd8, 280f67ca, 
808cad8, 8568044) + 22e
 0x280e782b Perl_mg_set (808cb5c, 83e8844, 2, 280f238a, 808ff18, 820c094) + 
6f
 0x280f241d Perl_pp_sassign (80484b4, bfbfed24, 2804ff2b, 28178564, 
bfbfee34, 9) + a1
 0x280f1fad Perl_runops_standard (2806a5d8, 28178564, bfbfed88, 280a08b1, 
1, 0) + 35
 0x280a0c26 S_run_body (1, 0, 28052cdd, 2807a040, 804a150, bfbfed64) + 12e
 0x280a08b1 perl_run (804c030, 804a0fc, bfbfedec, 8048fd5, 2806a5d8, 
2827251c) + 8d
 0x8049040 main (9, bfbfee34, bfbfee5c, 8048eb2, 8049b14, 0) + d8
 0x8048ebd _start (bfbfeee4, bfbfeef2, bfbfeef6, bfbfef0b, bfbfef0e, 
bfbfef11) + 85

lsof output:

COMMAND     PID  USER   FD   TYPE     DEVICE SIZE/OFF    NODE NAME
perl5.8.6 57376 smtpd  cwd   VDIR       4,14      512 2956294 
/usr/home/smtpd/qpsmtpd
perl5.8.6 57376 smtpd  rtd   VDIR       4,14      512       2 /
perl5.8.6 57376 smtpd  txt   VREG       4,14    10076 2190650 
/usr/local/bin/perl
perl5.8.6 57376 smtpd  txt   VREG       4,14   142236  455321 
/libexec/ld-elf.so.1
perl5.8.6 57376 smtpd  txt   VREG       4,14  1131877 2482217 
/usr/local/lib/perl5/5.8.6/mach/CORE/libperl.so
perl5.8.6 57376 smtpd  txt   VREG       4,14   120004 2841954 /lib/libm.so.3
perl5.8.6 57376 smtpd  txt   VREG       4,14    28644 2833198 
/lib/libcrypt.so.2
perl5.8.6 57376 smtpd  txt   VREG       4,14    43108 2841956 
/lib/libutil.so.4
perl5.8.6 57376 smtpd  txt   VREG       4,14   889908 2841961 /lib/libc.so.5
perl5.8.6 57376 smtpd  txt   VREG       4,14     7038 2482042 
/usr/local/lib/perl5/5.8.6/mach/auto/Sys/Hostname/Hostname.so
perl5.8.6 57376 smtpd  txt   VREG       4,14    17360 2481822 
/usr/local/lib/perl5/5.8.6/mach/auto/IO/IO.so
perl5.8.6 57376 smtpd  txt   VREG       4,14    18438 2481805 
/usr/local/lib/perl5/5.8.6/mach/auto/Fcntl/Fcntl.so
perl5.8.6 57376 smtpd  txt   VREG       4,14   112273 2481994 
/usr/local/lib/perl5/5.8.6/mach/auto/POSIX/POSIX.so
perl5.8.6 57376 smtpd  txt   VREG       4,14     7630 2081259 / 
(/dev/da0s1a)
perl5.8.6 57376 smtpd  txt   VREG       4,14    27641 2482012 
/usr/local/lib/perl5/5.8.6/mach/auto/Socket/Socket.so
perl5.8.6 57376 smtpd    0r  VCHR        2,2      0t0      22 /dev/null
perl5.8.6 57376 smtpd    1u  PIPE 0xc3d5622c        0         ->0xc3d56180
perl5.8.6 57376 smtpd    2u  PIPE 0xc3d5622c        0         ->0xc3d56180
perl5.8.6 57376 smtpd    3r  VREG       4,14     6131 2955766 
/usr/home/smtpd/qpsmtpd/qpsmtpd-forkserver
perl5.8.6 57376 smtpd    5u  IPv4                 0t0     TCP no PCB, 
CANTSENDMORE, CANTRCVMORE

Thread Next