Re: stable driver for multithreaded environment (IIS 5.X)

From: "Markus Donath" <md-postgres-donath(at)netapps(dot)de>
To: pgsql-odbc(at)postgresql(dot)org
Subject: Re: stable driver for multithreaded environment (IIS 5.X)
Date: 2003-12-09 13:07:48
Message-ID: br4hf4$29im$1@news.hub.org
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As no developer has answered yet, could anyone related to odbc driver
development answer the following questions:

1. Is there any development going on for the Windows version of the ODBC
driver ?
2. Are there known problems in a multithreaded environment (Webserver on
Windows 2000) and are they adressed ?
3. Is there a stable (maybe older, maybe commercial) version available for
multithreaded environments ?
4. Is anyone interessted in bug reports or am i completely wasting my time
when posting to this newsgroup ?

this would be very important for me.
PLEASE if anyone is working on the driver CONTACT ME.

thank you,
Markus.

"Markus Donath" <md-postgres-donath(at)netapps(dot)de> schrieb im Newsbeitrag
news:bpl77u$1mii$1(at)news(dot)hub(dot)org(dot)(dot)(dot)
> Hello,
>
> thank you for your reply.
> The application ran fine with ORACLE, accessed over OLEDB.
> I do not share connections over multiple threads. The Application uses the
> Windows ODBC connection pooling. For that, connections are always closed
> immediately after a statement was done, so that these connections are
always
> available for connection pooling when they are not in use. Connection
> pooling is the standard way when using IIS with ADO for data access, and
it
> works fine e.g. for ORACLE and MS SQL Server. One connection is always
used
> by just one thread (i think it would not work in any other way ?!)
>
> Did anyone here use OLEDB over ODBC in a similar environment ?
> Which driver was used in that case ?
>
> thank you,
> Markus.
>
>
>
>
>
>
> <markw(at)mohawksoft(dot)com> schrieb im Newsbeitrag
> news:39049(dot)24(dot)60(dot)194(dot)163(dot)1069423072(dot)squirrel(at)mail(dot)mohawksoft(dot)com(dot)(dot)(dot)
> > While I am not an ODBC developer, my first inclanation would be to
examine
> > your code for areas where you may be using the same connection resources
> > across multiple threads.
> >
> >
> > > hello,
> > >
> > > i've been making load-tests with Microsoft IIS 5.0 on Windows 2000,
> > > accessing postgresql via the Microsoft "OLEDB over ODBC" Driver using
> > > Postgres ODBC 7.03.0200.
> > > MDAC Version is 2.7 SP1 refresh.
> > > This version seems to have stability problems in a multithreading
> > > environment, same problems occur using version 7.03.0100:
> > >
> > > 1. the first bytes of column-data are corrupted under heavy load on
the
> > > webserver machine
> > > 2. after some minutes of testing, the webserver starts blocking
threads
> > > because of unhandled MDAC errors.
> > > Here is a stack-dump of one of the blocked threads:
> > >
> > > Warning: This thread is blocked by a Message Box
> > > Message Box Text: Runtime Error!
> > >
> > > Program: C:\WINNT\system32\dllhost.exe
> > >
> > > R6025
> > >
> > > - pure virtual function call
> > >
> > >
> > >
> > > Thread Type: MDAC Error being handled. Possible ASP page
> > > Executing Page: R:\INETPUB\XXXX\SHOP\FOLDER.ASP
> > >
> > > # ChildEBP RetAddr
> > > 00 0202d99c 77e234d6 USER32!NtUserWaitMessage+0xb
> > > 01 0202d9d0 77e33f21 USER32!DialogBox2+0x216
> > > 02 0202d9f4 77e23fdd USER32!InternalDialogBox+0xd1
> > > 03 0202dcac 77e24379 USER32!SoftModalMessageBox+0x752
> > > 04 0202ddf4 77e23871 USER32!MessageBoxWorker+0x247
> > > 05 0202de4c 77e24104 USER32!MessageBoxExW+0x77
> > > 06 0202de7c 77e232a2 USER32!MessageBoxExA+0xa0
> > > 07 0202de9c 7800bec3 USER32!MessageBoxA+0x49
> > > 08 0202debc 78007e22 MSVCRT!__crtMessageBoxA+0x81
> > > 09 0202e09c 78007f87 MSVCRT!_NMSG_WRITE+0x11f
> > > 0a 0202e0a4 7800bc7a MSVCRT!_amsg_exit+0x25
> > > 0b 0202e0ac 1f33f360 MSVCRT!_purecall+0x7
> > > 0c 0202e0b4 1f334aaf msadce!CSingleResult::~CSingleResult+0x27
> > > 0d 0202e0bc 1f35244b msadce!CSingleResult::`scalar deleting
> > > destructor'+0x8 0e 0202e0e8 1f352518
> > > msadce!CMultipleResults::mrInitFetch+0xb1
> > > 0f 0202e11c 1f43fa41 msadce!CMultipleResults::GetResult+0xbd
> > > 10 0202e15c 1f43f72c msado15!CConnection::Execute+0x13f
> > > 11 0202e318 1f43f5e6 msado15!_ExecuteAsync+0x16e
> > > 12 0202e328 1f43f4f9 msado15!ExecuteAsync+0x1f
> > > 13 0202e3f0 1f43ef4d msado15!CQuery::Execute+0x9fe
> > > 14 0202e498 1f43a33c msado15!CCommand::_Execute+0x147
> > > 15 0202e4d8 1f438174 msado15!CXLockContext::~CXLockContext+0x14
> > > 16 0202e638 1f4448f7 msado15!CRecordset::Open+0x571
> > > 17 0202e69c 779ffe61 msado15!CRecordset::put_CursorLocation+0x93
> > > 18 0a96c800 00650073 OLEAUT32!APP_DATA::FreeCachedMem+0x85
> > > WARNING: Frame IP not in any known module. Following frames may be
> > > wrong. 19 000008ec 00000000 0x650073
> > >
> > >
> > > As with all multithreading issues, the server runs fine when not under
> > > stress.
> > >
> > > Is there a stable version of this driver available (maybe an older
> > > version) ?
> > > Can anybody recommend a commercial driver version ?
> > >
> > > thank you,
> > > Markus.
> > >
> > >
> > >
> > >
> > > ---------------------------(end of
broadcast)---------------------------
> > > TIP 8: explain analyze is your friend
> >
> >
> >
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 9: the planner will ignore your desire to choose an index scan if
your
> > joining column's datatypes do not match
> >
>
>

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