FIX: Applications That Use OLE DB Provider for VSAM Stop Responding (321536)


The information in this article applies to:

  • Microsoft SNA Server 4.0 SP1
  • Microsoft SNA Server 4.0 SP2
  • Microsoft SNA Server 4.0 SP3
  • Microsoft SNA Server 4.0 SP4
  • Microsoft Host Integration Server 2000
This article was previously published under Q321536

SYMPTOMS

User developed applications that use COM+ components that call in to the OLE DB Provider for AS/400 and VSAM may experience problems that cause the application to appear as though it has stopped responding.

When you use the OLE DB Provider for AS/400 and VSAM, communication between the application and the Host system may stop responding, and any new applications that call in to the provider may also stop responding.

Through investigation, it was determined that if an application makes two simultaneous calls in to the provider, lock contention occurs that results in the observed failure.

CAUSE

This problem is the result of incorrect resource locking order used within the provider source code.

RESOLUTION

SNA Server 4.0

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft SNA Server 4.0 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English-language version of this fix should have the following file attributes or later: 
   Date         Time   File name
   ---------------------------------
   17-Jan-2002  01:07  Ddmserv.exe
   17-Jan-2002  01:07  Ddmapi.dll

NOTE: Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.

Host Integration Server 2000

To resolve this problem, obtain the latest service pack for Host Integration Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

328152 How to Obtain the Latest Host Integration Server 2000 Service Pack

WORKAROUND

It is possible to work around this problem by implementing in the application code a global mutex to make sure that applications do not call in to the provider at the same time from two different threads.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Host Integration Server 2000 Service Pack 1.
Modification Type:MinorLast Reviewed:10/6/2005
Keywords:kbbug kbfix kbHostIntegServ2000preSP1fix kbHostIntegServ2000SP1fix KB321536 kbAudDeveloper
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