Microsoft KB Archive/180705

= APPC DISPLAY Call May Return AP_COMM_SUBSYSTEM_ABENDED. =

Article ID: 180705

Article Last Modified on 6/5/2006

-

APPLIES TO


 * Microsoft SNA Server 3.0 Service Pack 4
 * Microsoft SNA Server 4.0
 * Microsoft SNA Server 3.0 Service Pack 2
 * Microsoft SNA Server 4.0

-



This article was previously published under Q180705



SYMPTOMS
If a Win32 APPC application calls the SNA Server DISPLAY function to retrieve a list of all configured remote APPC LU's (in other words, sets the plu_def_info option), the following symptoms may occur:

 the DISPLAY call may return with the following error:

primary_rc = 0xF003 (AP_COMM_SUBSYSTEM_ABENDED)

 The following event may appear in the Windows NT application event log:

Event ID: 706

Source: SNA Server

Description:

Connection to client has been aborted due to too many (100)

pending writes.



This problem has been observed when configuring IBM Personal Communications for the AS/400 (version 4.1) while using the SNA Server Windows NT or Windows 95 client software. This problem occurs when the SNA Server is configured with a large number of local APPC LU/remote APPC LU/mode partnerships. In the customer's failure scenario, there were over 2300 local APPC LU's configured, each partnered with up to 4 remote APPC LU's.



CAUSE
The SNA Server was incorrectly reporting information on all the local APPC LU's defined, even though the application was only requesting remote APPC LUs (via the plu_def_info option). When attempting to send this large response to the client's DISPLAY request, the SNA Server exceeded 100 consecutive pending write requests to the client, causing the default "MaxPendingWrites" counter to be exceeded. For more information about Event 706 and MaxPendingWrites, see the following article in the Microsoft Knowledge Base:

142037 SNA Server Fails to Release Memory in SNA TCP/IP Interface DLL



STATUS
Microsoft has confirmed this to be a problem in SNA Server version 3.0, 3.0 Service Pack 1 (SP1), 3.0 SP2 and 4.0.

This problem was corrected in the latest SNA Server versions 3.0 and 4.0 U.S. Service Packs. For information on obtaining these Service Packs, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Keywords: kbbug kbfix kbqfe kbhotfixserver KB180705

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.