TP May Start Slowly When Using Dynamic Remote APPC LU Definition

ID: Q249820

The information in this article applies to:

Microsoft SNA Server, versions 4.0, 4.0 SP1, 4.0 SP2, 4.0 SP3, 4.0 U.S. SP1

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

An APPC application may experience a slow response time when it is configured to use an SNA subdomain with multiple SNA Server computers if the Supports Dynamic Remote APPC LU Definition option is enabled on several computers.

CAUSE

If an APPC application specifies a Local LU Alias when calling TP_STARTED, the APPC interface incorrectly tries SNA Server computers that are configured to support dynamic remote APPC LU definition, even if those computers do not support the Local LU Alias being requested. Because additional time is spent connecting to those other servers, the opening of the application may be delayed.

WORKAROUND

To work around this issue, try one of the following:

If you are not using Supports Dynamic Remote APPC LU Definition, disable it by clicking to uncheck the Supports Dynamic Remote APPC LU Definition check box on the SNA Server computer(s).

-OR-

Configure the LUWIDSUP=NO registry entry on the computer where the APPC program is running.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

On SNA Windows NT clients:

HKLM\System\CurrentControlSet\Services\SnaBase\Parameters\Client
LUWIDSUP:REG_SZ:NO

On SNA Windows 95 clients:

HKLM\Software\Microsoft\SnaBase\Parameters\Client
LUWIDSUP:REG_SZ:NO

Setting this registry entry to NO defers resource allocation until an [MC_]ALLOCATE is issued. This causes WAPPC32 to issue the GetServerList with the Remote APPC LU alias only, and not the local. Therefore, the resource allocation proceeds correctly.

STATUS

Microsoft has confirmed this to be a problem in SNA Server 4.0.

Additional query words:

Keywords : sna4
Version : WINDOWS:4.0,4.0 SP1,4.0 SP2,4.0 SP3,4.0 U.S. SP1
Platform : WINDOWS
Issue type :