PRB: Application Stops Responding; IBM CICS/VSE Terminal Unavailable

ID: Q216202

The information in this article applies to:


The client application may block after a period of time of normal operation. If it is a Visual Basic application and you click its graphical user interface, the following message appears in a message box:

This action cannot be completed because the other application is busy. Choose 'Switch To' to activate the busy application and correct the problem.
The COMTI component is participating in an atomic transaction as defined by Microsoft Transaction Server. This problem does not occur otherwise.

The following CICS informational message appears in the CICS log:
DFH2411I ???? CSNE 19:39:45 <LU name> ATTEMPTED INVALID LOGON", where 'LU name' is a fully-qualified Logical Unit name.
Additionally, the following entry may appear in the Application Event Log:

Event ID: 18
Source: SNA Server
Type: Information
Category: None

APPC session activation failure: BIND negative response or UNBIND
request received

   Sense data   = 08063426   (NOTE: 0032xxxx indicates UNBIND
   Connection   = ALHOST
   LU alias     = T22158DD
   PLU alias    = DBDCCIDS
   Mode name    = MODE1    


If the COMTI method invocations are at a high-enough rate for a given configuration, the same CICS terminal session is reused for a series of calls. However, if the rate it too low, the CICS terminal session is ended, and a new terminal session is STARTED on another terminal for the next COMTI method.

The CICS terminal sessions are named in succession, as in this example: -99A, -99B, -99C, ... -99Z. When the use of one of the terminals is ended, CICS/VSE does not free its name for reuse at a later time. When the list of available names is completely used up, the COMTI application blocks.

When this happens, the last entries in the CICS log show as follow:

 DFH3461I -99X CSNE 19:37:39 NODE COMTI01 SESSION STARTED                       
 DFH3462I -99X CSNE 19:37:57 NODE COMTI01 SESSION TERMINATED                    
 DFH3461I -99Y CSNE 19:38:30 NODE COMTI01 SESSION STARTED                       
 DFH3462I -99Y CSNE 19:38:48 NODE COMTI01 SESSION TERMINATED                    
 DFH3461I -99Z CSNE 19:39:11 NODE COMTI01 SESSION STARTED                       
 DFH3462I -99Z CSNE 19:39:34 NODE COMTI01 SESSION TERMINATED                    
 DFH2411I ???? CSNE 19:39:45 &lt;LU name&gt; ATTEMPTED INVALID LOGON 


Inactivate and reactivate the LU to allow normal processing to resume.


Three IBM PTFs have been identified for appliction to the host system to fix this IBM CICS/VSE problem: UQ23940, UQ14297 and UQ23939.

IBM APAR, PQ19793, indicates that the SNA Server MODE property 'Automatic Activation Limit,' could be set to 10 from 0 for a "LOCAL FIX." This is misleading, but the customer may wish to maximize this value. For example, if the SNA Server MODE property, 'Parallel Session Limit,' is set to 128, set 'Automatic Activation Limit' to 128. Microsoft has NOT found this to be a successful solution to the problem.

Additional query words:

Keywords          : 
Version           : WINDOWS:4.0 SP2
Platform          : WINDOWS 
Issue type        : kbprb 

Last Reviewed: April 16, 1999