sqlgrey-users

[Sqlgrey-users] sqlgrey segmentation fault!

[Marco F. <fa...@cs...>]

Hi all,
I run daemon sqlgrey 1.6.8 with Mysql DBMS. DB access is "sync", not
"async".

I have just installed it in test environment with no connections:

Red Hat Enterprise Linux Server release 5.2
Linux vm-greylist1 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:15 EDT 2008 
x86_64 x86_64 x86_64 GNU/Linux

I start sqlgrey and it works fine. I make SMTP session: it's ok, like 
expected.
After a day, I made another smtp session: sqlgrey segfault! This is the 
only log written:

kernel:<6>sqlgrey[9861]: segfault at 0000000000000008 rip 
0000003d2ca489d5 rsp 00007fff031e68e0 error 4

Could you help me?

Thank you very much
Regards
Marco

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Lionel B. <lio...@bo...>]

Marco Favero a écrit, le 07/11/2008 01:43 PM :
> Hi all,
> I run daemon sqlgrey 1.6.8 with Mysql DBMS. DB access is "sync", not
> "async".
>
> I have just installed it in test environment with no connections:
>
> Red Hat Enterprise Linux Server release 5.2
> Linux vm-greylist1 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:15 EDT 2008 
> x86_64 x86_64 x86_64 GNU/Linux
>
> I start sqlgrey and it works fine. I make SMTP session: it's ok, like 
> expected.
> After a day, I made another smtp session: sqlgrey segfault! This is the 
> only log written:
>
> kernel:<6>sqlgrey[9861]: segfault at 0000000000000008 rip 
> 0000003d2ca489d5 rsp 00007fff031e68e0 error 4
>
> Could you help me?
>   

It's most probably hardware related. Segfaults happen when a process 
tries to access memory at an address it hasn't access too. SQLgrey is 
coded in Perl and doesn't deal with memory access at all leaving it to 
the Perl interpreter. So there's really two possible sources :
- Buggy perl interpreter or native library (the DBD MySQL driver for 
example is probably coded with both Perl and C to interface with the 
MySQL client library),
- Dodgy hardware.

As you are the first to report such a problem it's far more likely that 
it's a problem specific to your installation : RedHat being used widely 
the only remaining possibility is the hardware.

Running memtest86+ might confirm the problem.

Lionel

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Marco F. <fa...@cs...>]

Lionel Bouton wrote:
> Marco Favero a écrit, le 07/11/2008 01:43 PM :
>> Hi all,
>> I run daemon sqlgrey 1.6.8 with Mysql DBMS. DB access is "sync", not
>> "async".
>>
>> I have just installed it in test environment with no connections:
>>
>> Red Hat Enterprise Linux Server release 5.2
>> Linux vm-greylist1 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:15 EDT 2008 
>> x86_64 x86_64 x86_64 GNU/Linux
>>
>> I start sqlgrey and it works fine. I make SMTP session: it's ok, like 
>> expected.
>> After a day, I made another smtp session: sqlgrey segfault! This is the 
>> only log written:
>>
>> kernel:<6>sqlgrey[9861]: segfault at 0000000000000008 rip 
>> 0000003d2ca489d5 rsp 00007fff031e68e0 error 4
>>
>> Could you help me?
>>   
> 
> It's most probably hardware related. Segfaults happen when a process 
> tries to access memory at an address it hasn't access too. SQLgrey is 
> coded in Perl and doesn't deal with memory access at all leaving it to 
> the Perl interpreter. So there's really two possible sources :
> - Buggy perl interpreter or native library (the DBD MySQL driver for 
> example is probably coded with both Perl and C to interface with the 
> MySQL client library),
> - Dodgy hardware.
> 
> As you are the first to report such a problem it's far more likely that 
> it's a problem specific to your installation : RedHat being used widely 
> the only remaining possibility is the hardware.
> 
> Running memtest86+ might confirm the problem.
> 
> Lionel

I tried with memtest, but I exclude hardware problem - I have same 
segmentation on two identical hardware.

My systems are:
perl 5.8.8

Modules installed:
IO::Multiplex is up to date (1.09)
Net::Server is up to date (0.97)
DBD::mysql is up to date (4.007)
DBI is up to date (1.605)

Mysql local to DBD and sqlgrey is:
mysql.x86_64      5.0.22-2.1.0.1
but db_host is not localhost: remote DBMS could be another subversion.

I don't known what thinking about...
For debugging purpose I also tried to reduce db_cleandelay to few 
seconds, but it is useless. Segmentation fault happens only after 
several hours from sqlgrey start, I notice after a day during first 
connection I make.

Maybe it's useful to know which versions of module above surely works 
together?

I notice this problem only with sqlgrey, so I've tried to ask here.
Thank you very much again
Marco

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Chris S. <ch...@cs...>]

On Mon, 14 Jul 2008, Marco Favero wrote:

> I tried with memtest, but I exclude hardware problem - I have same
> segmentation on two identical hardware.

You could just be very unlucky..

Might be worth trying to run it under Valgrind if you can, see if it 
catches anything.  There's also the glibc debugging malloc stuff you could 
try too, have a look at malloc(3) and its MALLOC_CHECK_ environment 
variable.

cheers,
Chris
-- 
 Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC

This email may come with a PGP signature as a file. Do not panic.
For more info see: http://en.wikipedia.org/wiki/OpenPGP

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Karl O. P. <ko...@me...>]

On 07/14/2008 04:29:57 AM, Marco Favero wrote:
> Lionel Bouton wrote:
> 
> I tried with memtest, but I exclude hardware problem - I have same
> segmentation on two identical hardware.

You sometimes have to run memtest for several passes,
I usually run it overnight, before getting an error.

You could (possibly) have a design flaw in the hardware.
Heat related problems are especially tricky.

You could also try isolating the problem, somewhat,
by using something besides MySQL for the db backend.
If the problem goes away you've made progress.
Likewise, if you move the MySQL backend to the local
box and the problem goes away that says something too.
About all you can do is take the divide and conquer
approach until you've got something reproducible
that somebody else can work on.

Karl <ko...@me...>
Free Software:  "You don't pay back, you pay forward."
                  -- Robert A. Heinlein

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Elio T. <el...@to...>]

Karl O. Pinc wrote:

>> I tried with memtest, but I exclude hardware problem - I have same
>> segmentation on two identical hardware.
> 
> You sometimes have to run memtest for several passes,
> I usually run it overnight, before getting an error.

I have a laptop which runs memtest forever with no errors, but segfaults when 
booting Linux... and hangs often with XP. It seems to be a problem in the 
processor.

Elio

Re: [Sqlgrey-users] sqlgrey segmentation fault!

[Yann C. <yan...@un...>]

Marco Favero a écrit :
> Hi all,
>   
Hi
> I run daemon sqlgrey 1.6.8 with Mysql DBMS. DB access is "sync", not
> "async".
>
> I have just installed it in test environment with no connections:
>
> Red Hat Enterprise Linux Server release 5.2
> Linux vm-greylist1 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:15 EDT 2008 
> x86_64 x86_64 x86_64 GNU/Linux
>
>   
The name of the host and the kernel version makes me ask :
Isn't it a Xen Virtual Machine ?
If yes, aren't you running a 64 bits kernel with a 32 bits installation ?

That sometimes gives problem like the one you have. I believe it's a
compilation problem of some binaries/libraries.
> kernel:<6>sqlgrey[9861]: segfault at 0000000000000008 rip 
> 0000003d2ca489d5 rsp 00007fff031e68e0 error 
Regards,

-- 
Yann Cézard - Administrateur Systèmes Serveurs
Centre de Ressources Informatiques - http://cri.univ-pau.fr
Université de Pau et des Pays de l'Adour - http://www.univ-pau.fr