DOCUMENT:Q274569  23-OCT-2000  [iis]
TITLE   :FIX: MTS or IIS w/ ODBC Connection Pooling Hangs If DB Unavail.
PRODUCT :Internet Information Server
PROD/VER:WINDOWS:2.1 SP2; winnt:2.0,4.0
OPER/SYS:
KEYWORDS:kbWinNT4sp6fix

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Internet Information Server 4.0 
 - Microsoft Transaction Server 2.0 
 - Microsoft Data Access Components version 2.1 SP2 
-------------------------------------------------------------------------------

SYMPTOMS
========

When ODBC connection pooling is enabled, if database servers are down or
unavailable due to network connectivity issues, Internet Information Server
(IIS) or Microsoft Transaction Server (MTS) may stop responding (hang).

CAUSE
=====

This behavior is caused by a bug in the resource dispenser (Mtxdm.dll). The
threads that perform connection pooling wait for the ODBC thread that is trying
to perform an ODBC call, which results in a deadlock condition.


RESOLUTION
==========

The resource dispenser has been modified to resolve this problem. To obtain the
corrected version of Mtxdm.dll, install Microsoft Data Access Components (MDAC)
version 2.5 or later from the following Microsoft Web Site:

   http://www.microsoft.com/data (http://www.microsoft.com/data)

You can also obtain this fix by installing Microsoft Windows NT 4.0 Service Pack
6a or later. For more information, see the following Web site:

   http://www.microsoft.com/ntserver/ (http://www.microsoft.com/ntserver/)

STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article.

This problem has been corrected in MDAC version 2.5 and later, and in Windows NT
4.0 Service Pack 6a and later.

Additional query words:

======================================================================
Keywords          : kbWinNT4sp6fix 
Technology        : kbMTSsearch kbiisSearch kbAudDeveloper kbiis400 kbMDACSearch kbMDAC210SP2 kbMTS200
Version           : WINDOWS:2.1 SP2; winnt:2.0,4.0
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2000.