LUA Applications Unable to Acquire DDDLU Sessions in LUA Pools

ID: Q237194

The information in this article applies to:

Microsoft SNA Server, versions 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 3.0 SP4, 4.0, 4.0 SP1, 4.0 SP2

SYMPTOMS

LUA applications may display the following error message when trying to start a host session through SNA Server by issuing an RUI_INIT or SLI_OPEN:

Primary Return Code = 0x0014 (LUA_UNSUCCESSFUL)
Secondary Return Code = 0x00000087 (LUA_COMMAND_COUNT_ERROR)

Because SNA Server's TN3270 server is a LUA application, this problem can affect TN3270 clients as well. When configured in TN3270E mode, the 3270 applet included with SNA Server displays the following error message when this problem occurs:

ERROR - An error occurred during device type/name processing.

Other TN3270 emulators may display different error messages when this occurs. However, LUA API traces captured on SNA Server show the return codes listed previously when the problem occurs.

This error can occur when each of the following circumstances are met:

The host is configured to use DDDLUs (Dynamically Defined Dependent LUs).
The DDDLUs are defined as LUA LUs and are assigned to an LUA Pool. For TN3270, the LUA Pool would also be assigned to the TN3270 Server.
More than five minutes has past since the host sent the ACTPU (Activate Physical Unit) RU to the SNA Server. The ACTPU is sent by the host when the host connection defined in SNA Server is started, therefore, this would occur five minutes after starting the connection.

Users are able to obtain host sessions that are activated within the five-minute window described here.

CAUSE

SNA Server does not send the required NMVTs (Network Management Vector Transport) to the host to request activation of DDDLUs five minutes after the receipt of the ACTPU when using LUA LUs assigned to LUA Pools.

This same problem was corrected for 3270 LU Pools in SNA Server version 3.0 Service Pack 1 and later. For additional information about the 3270 LU Pool issue, please see the following article in the Microsoft Knowledge Base:

Q164650 SNA Server Fails to Activate DDDLU Pooled LU

The change implemented for 3270 LU Pools was not implemented for LUA pools at that time.

RESOLUTION

To resolve this problem, obtain the latest service pack for SNA Server version 4.0. For additional information, please see the following article in the Microsoft Knowledge Base:

Q215838 How to Obtain the Latest SNA Server Version 4.0 Service Pack

STATUS

Microsoft has confirmed this to be a problem in Microsoft SNA Server versions 3.0, 3.0 SP1, 3.0 SP2, 3.0 SP3, 3.0 SP4, 4.0, 4.0 SP1, 4.0 SP2. This problem was first corrected in SNA Server version 4.0 Service Pack 3.

MORE INFORMATION

After you apply the update, SNA Server sends the required NMVT RUs to the host to request activation of the requested LUA LUs.

For additional information about SNA Server's DDDLU support for 3270 and LUA LUs, please see the following articles in the Microsoft Knowledge Base:

Q161492 LU Session Activation Using Dynamically Defined Dependent LUs

Q164592 Dynamically Defined Dependent LU Support for LUA LUs

Additional query words:

Keywords : sna4sp3fix sna3 sna3sp1 sna3sp2 sna3sp3 sna3sp4 sna4 sna4sp1 sna4sp2
Version : WINDOWS:3.0,3.0 SP1,3.0 SP2,3.0 SP3,3.0 SP4,4.0,4.0 SP1,4.0 SP2
Platform : WINDOWS
Issue type : kbbug