FIX: Multiple LU1 Print Sessions Cause Event ID 12 When the SNA Print Service Is Under Stress (826438)

SYMPTOMS

When the SNA Print service is running multiple 3270 LU1 printer sessions at the same time, the SNA Print service may, under stress, send a negative acknowledgement to a BID request after the bracket is already open and the BID request has already been acknowledged. When this behavior occurs, the SNA Server service recognizes that this is a session error and ends the session. When this error occurs, all printing for the session stops, and print jobs may queue up on the host system.

SNA Server also logs the following event in the application event log:

Event Type: Warning
Event Source: SNA Server
Event Category: None
Event ID: 12

Description: A 3270 Session was lost due to a protocol error in the 3270 emulator. A user has lost their 3270 session due to a non-recoverable protocol error caused by the 3270 emulator being used. The following user encountered this error.

Client Domain: domainname
Client User: username
LU name: LUNAME
FMI Sense Code: 4011

RESOLUTION

Service pack information

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

328152 How to obtain the latest service pack for Host Integration Server 2000

Hotfix information

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

   Date         Time   Version            Size    File name
   --------------------------------------------------------------
   12-Aug-2003  00:28  5.0.0.935          20,752  Msg5250.dll      
   12-Aug-2003  00:28  5.0.0.935         250,128  Ppd3270.dll      
   12-Aug-2003  00:28  5.0.0.935         139,536  Ppd5250.dll      
   12-Aug-2003  00:28  5.0.0.935          49,424  Prmngext.dll     
   12-Aug-2003  00:27  5.0.0.935         209,168  Snacfg.dll  
   12-Aug-2003  00:28  5.0.0.935          24,848  Snaxlt.dll       
   12-Aug-2003  00:28  5.0.0.935         282,896  Winvprt.dll      
   12-Aug-2003  00:28  5.0.0.935          57,616  Pdfcomp.exe      
   12-Aug-2003  00:28  5.0.0.935          94,480  Snaprint.exe

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

MORE INFORMATION

When you examine SNA traces of this problem, you notice the following data flow. This data flow shows that the SNA Print service sends a second (negative) acknowledgement after the SNA Print service has already responded to the BID request:

Host System		SNA Server service		SNA Print service
===========		==================		=================
Print Data (BB EB) ->
			BID ->
							<- BID ACK
			Print Data ->
			BETB ->
							<- BID NACK
			<- +RSP