FreeTDS Development Group

["Mark Gebhardt" <mark AT saebex.com>]

Hi all

BACKGROUND:
I am running Python Webware (0.5.1-rc3)( RedHat Linux 7.0 / Apache / WebKit
/ ThreadedAppServer) and using it (via intermediate Python classes (and Tom
Osborne's Python msdb library (ex Datautils-0.1) , using FreeTDS (0.52) to
access MS SQL server on a remote Windows 200 box.

PROBLEM:
Most of the time this works just fine. However (and here's the thing)
sometimes it all falls over in a heap with a Segmentation Fault (see error
message below). It SEEMS that this only occurs when I try to query SQL
server such that it returns no records.

THOUGHTS:
My current assumption is that the Seg Fault is coming out of either msdb or
FreeTDS (and I will spend much time today trying to repeat the SegFault
without using Webware in order to verify this).

QUESTION:
1) (for anyone) does anyone have any thoughts / experience / patches that
could help get this sorted out before we go live next friday (31 August)

2) (for the Webware guys) is there any way I can easily isolate my calls to
SQL Server from the AppServer so that, even if I do get these errors, they
will at least not take down my entire website. I guess I could do this by
forking a process, implementing some sort of shared memory or whatever, but
I was hoping that Webware may have some sort of multi-process state, where I
may lose one server thread but the rest would trundle on happily ??

All help will be hugely appreciated

Thanks,
Mark



############### error message generated by Webware
############################
BEGIN REQUEST
Thu Aug 23 09:54:45 2001
receiving request from <socket object, fd=6, family=2, type=1, protocol=0>
request has keys: format, time, environ, input
request uri =
/cgi-bin/WebKitMark.cgi/SmartSuite/User/WelcomePage?Source=Bizland&Id=
query string = {'Id': '', 'Source': 'Bizland'}
./AppServer: line 3:  5210 Segmentation fault      /usr/bin/env python
Launch.py ThreadedAppServer $*
#######################################


----
Mark Gebhardt, SAEBEX
tel: +27 21 6714424 x227 | fax: +27 21 6714529
email: mark AT saebex.com   | web: http://www.saebex.com

-----Original Message-----
From: webware-discuss-admin AT lists.sourceforge.net
[mailto:webware-discuss-admin AT lists.sourceforge.net]On Behalf Of Jay
Love
Sent: 15 August 2001 04:28
To: Mark Gebhardt
Cc: webware-discuss AT lists.sourceforge.net
Subject: RE: [Webware-discuss] AppServer core dump



We've standardized on Threaded.  Async is more complicated and its
theoretical advantages don't seem to apply as well when we're not the
front line server (ie there's a webserver actually talking to the client
and we talk to the webserver).

In any case, I doubt that's your problem, but switch AppServers just in
case.  You can switch by editing the file 'AppServer'.

Honestly, the only things I've ever seen crash python are buggy C
modules (like database adapters) or bad memory in the machine.  When
I've had Webware core dump, I've traced it to one of these problems.  If
the Async appserver were the problem you'd get a traceback.

Anyway, try switching appservers and let us know.

Jay


On 14 Aug 2001 09:03:17 +0200, Mark Gebhardt wrote:
> I'm using the default - Async (on Linux RedHat7.0) - should I rather be
> using threaded? Is it more stable?
>
> Thanks
> Mark
>
> ----
> Mark Gebhardt, SAEBEX
>
> -----Original Message-----
> From: webware-discuss-admin AT lists.sourceforge.net
> [mailto:webware-discuss-admin AT lists.sourceforge.net]On Behalf Of Jay
> Love
> Sent: 14 August 2001 03:27
> To: Mark Gebhardt
> Cc: webware-discuss AT lists.sourceforge.net
> Subject: Re: [Webware-discuss] AppServer core dump
>
>
> What AppServer are you using?  Async or Threaded?
>
> If your just using the default, that would be Async on Linux and
> Threaded on windows.
>
> Jay
>
>
> Mark Gebhardt wrote:
>
> >Hi
> >
> >I've just managed to make my AppServer core dump by requesting a URL it
> >didn't like, thought I'd better flag it in case its an unidentified bug.
> >
> >Here are the details:
> > - Webware version 0.5.1rc3
> > - URL I typed:
>
>http://saeb0/cgi-bin/WebKitMark.cgi/SmartSuite/User/UserDetailsPage?Source=
> B
> >izland&Id=user AT company.com
> > - AppServer log output:
> >
> >Mon Aug 13 16:55:07 2001
> >receiving request from <socket object, fd=8, family=2, type=1,
protocol=0>
> >received 1440 bytes
> >request has keys: format, time, environ, input
> >request uri =
>
>/cgi-bin/WebKitMark.cgi/SmartSuite/User/UserDetailsPage?Source=Bizland&Id=u
> s
> >er AT company.com
> >query string = {'Id': 'user AT company.com', 'Source': 'Bizland'}
> >./AppServer: line 3: 20070 Segmentation fault      (core dumped)
> >/usr/bin/env python Launch.py AsyncThreadedAppServer $*
> >
> >After restarting the server, I was able to access the relevant page with
no
> >problems. Is there anywhere else I should try to get info on this crash
> >from?
> >
> >Does anyone know if this is an identified bug?
> >
> >Thanks
> >Mark
> >
> >----
> >Mark Gebhardt, SAEBEX
> >
> >
> >_______________________________________________
> >Webware-discuss mailing list
> >Webware-discuss AT lists.sourceforge.net
> >http://lists.sourceforge.net/lists/listinfo/webware-discuss
> >
>
>
>
>
> _______________________________________________
> Webware-discuss mailing list
> Webware-discuss AT lists.sourceforge.net
> http://lists.sourceforge.net/lists/listinfo/webware-discuss



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