[MC_]ALLOCATE Contention Winner Request Never Completes

ID: Q195999

The information in this article applies to:

Microsoft SNA Server, versions 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 4.0, 4.0 SP1

SYMPTOMS

If an Advanced Program-to-Program Communications (APPC) or Common Programming Interface for Communications (CPIC) application attempts to allocate a contention winner session (by setting rtn_ctl = AP_WHEN_CONWINNER_ALLOCATED), the [MC_]ALLOCATE or CMALLC request never completes. When SNA Server fails to negotiate any contention winner sessions with the remote system, the server fails to reject the client allocation request.

This problem was found while testing the COM Transaction Integrator (COMTI) feature included with SNA Server 4.0 while the SNA Server APPC mode "minimum contention winner limit" was set to 0. COMTI allocates contention winner sessions, so this mode configuration will not function properly.

CAUSE

The SNA Server was failing to return an error to a client contention winner request when SNA Server had not negotiated any contention winner sessions with the remote system.

RESOLUTION

SNA Server 3.0

A supported fix that corrects this problem is now available from Microsoft, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Microsoft SNA Server version 3.0 service pack that contains this fix.

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 on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/support/supportnet/default.asp

The English version of this fix should have the following file attributes or later:


      File Name        Date       Time
      ----------------------------------
      Snaservr.exe
      Trcservr.exe

NOTE: The Date and Time information for the above files will be provided in this article as soon as it becomes available.

NOTE: Due to file dependencies, the most recent fix that contains the above files may also contain additional files. NOTE: If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base: Q154871 Determining If Your Product Is Eligible for No-Charge Technical Support

SNA Server 4.0

This problem was corrected in the latest SNA Server version 4.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

WORKAROUND

Configure SNA Server's APPC mode definition so that the minimum contention winner limit is greater than 0. This is required in order for APPC or CPIC applications to successfully allocate contention winner sessions.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft SNA Server versions listed above.

Additional query words:

Keywords :
Version : WINDOWS:3.0,3.0 SP1,3.0 SP2,3.0 SP3,4.0,4.0 SP1
Platform : WINDOWS
Issue type : kbbug