Problem Starting Two Non-Queued TPs Simultaneously on Win3.x

ID: Q161775


The information in this article applies to:
  • Microsoft SNA Server, versions 2.1, 2.11


SYMPTOMS

If the host allocates two conversations at the same time, causing two instances of a non-queued autostarted TP to be invoked on an SNA Server Windows 3.x client, the following sequence of events occurs:

  1. Two instances of the program are started.


  2. The first program issues a RECEIVE_ALLOCATE that completes after 20 or more seconds, and normal data flow occurs.


  3. The second program issues a RECEIVE_ALLOCATE that fails with the following error:
    primary_rc = 0x0002 (AP_STATE_CHECK)
    secondary_rc = 0x00000509 (AP_ALLOCATE_NOT_PENDING)
    When this occurs, the first program stops responding.


  4. The computer running SNA Server may report the following events in the Windows NT Application event viewer:
    Event 60
    Failed to invoke APPC TP <value>, sense data = X'084C0000'
    AP_TRANS_PGM_NOT_AVAIL_NO_RETRY.
    Event 557
    DLOAD has timed out.
    Event 575
    Failed to Execute a program, RC=8 name=<value>.


If there is a 30-second delay between host attach requests, the problem doesn't occur; both APPC TP's are invoked, and they run fine.


CAUSE

This is a problem in the SNA Server 2.11 Windows 3.x client. If the Windows 3.x client receives two dynamic load requests from two different servers within five seconds, the SNA client (Wdmod.dll) may send the second acknowledgement (RCV_ALLOC) message to the wrong server.


RESOLUTION

To resolve this problem, obtain the hotfix mentioned below.


STATUS

Microsoft has confirmed this to be a problem in SNA Server version 2.1 and 2.11. A supported fix is now available, but has not been fully regression- tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Additional query words: prodsna

Keywords : kbnetwork snaappc snacpic snaprog kbbug2.10 kbbug2.11
Version : WINDOWS:2.1,2.11
Platform : WINDOWS
Issue type :


Last Reviewed: November 20, 1999
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