Squid +pid 48635 (squid), uid 100: exited on signal 6 (core dumped)

[eculp at bafirst.com]

Quoting eculp at bafirst.com:

> Quoting Kris Kennaway <kris at obsecurity.org>:
>
>> On Mon, Oct 24, 2005 at 07:15:54AM -0500, Edwin L. Culp wrote:
>>> 4 Current servers running current and squid-2.5.11_3 that had no
>>> problems maybe a month ago are now dumping core and logging the
>>> following:
>>>
>>> +pid 48635 (squid), uid 100: exited on signal 6 (core dumped)
>>
>> I'm seeing this too.  In fact squid has always been pretty unreliable
>> for me on busy hosts - it often just exits without leaving any trace
>> in the logs.
>>
>> Kris
> Hi Kris,
> Thanks.  I don't feel alone anymore. As I've heard many times "misery 
> loves company". I can now confirm it, yet again.;)  In this case, I 
> have been using and depending on squid since the late 90's and have 
> had some issues as with everything else but all in all it has helped 
> me a lot more that hindered.  I would not want to live without it.  
> Habits are hard to break ;)
>
> If I can just make a little extra time today I'm going to recompile 
> squid, get a backtrace and go from there with some great folks who 
> have offered to help and share our findings with all.

Finally got it done and the problem continues.  I have found the following:
  an assertion message in the squid/logs/cache.log that I understand
  is generated when squid exits:

2005/10/28 06:52:30| storeDiskdSend OPEN: (35) Resource temporarily 
unavailable
2005/10/28 06:52:30| storeDiskdSend: msgsnd: (35) Resource temporarily 
unavailable
2005/10/28 06:52:30| assertion failed: diskd/store_io_diskd.c:494: 
"++send_errors < 100"
2005/10/28 06:52:34| Starting Squid Cache version 2.5.STABLE11 for 
i386-portbld-freebsd7.0...
2005/10/28 06:52:34| Process ID 65317
2005/10/28 06:52:34| With 7104 file descriptors available

I recompiled squid without stripping it and the bt of the core file yielded:

# gdb /usr/local/sbin/squid squid.core
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-marcel-freebsd"...(no debugging 
symbols found)...
Core was generated by `squid'.
Program terminated with signal 6, Aborted.
Reading symbols from /lib/libcrypt.so.3...(no debugging symbols found)...done.
Loaded symbols for /lib/libcrypt.so.3
Reading symbols from /lib/libm.so.4...(no debugging symbols found)...done.
Loaded symbols for /lib/libm.so.4
Reading symbols from /lib/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/libc.so.6
Reading symbols from /libexec/ld-elf.so.1...(no debugging symbols 
found)...done.
Loaded symbols for /libexec/ld-elf.so.1
#0  0x281e9c6f in kill () from /lib/libc.so.6
(gdb) bt
#0  0x281e9c6f in kill () from /lib/libc.so.6
#1  0x281e9c0c in raise () from /lib/libc.so.6
#2  0x281e8920 in abort () from /lib/libc.so.6
#3  0x08065e3f in xassert ()
#4  0x080aa110 in storeDiskdSend ()
#5  0x080aa7aa in storeDiskdCreate ()
#6  0x08097624 in storeCreate ()
#7  0x0809b454 in storeSwapOut ()
#8  0x080785c4 in httpReadReply ()
#9  0x0806530e in comm_poll ()
#10 0x08085f49 in main ()
(gdb) Hopefully this can help someone more knowledgeable than I make a 
suggestion. Thanks,

ed
>
> a very good day to all,
>
> ed
>
>