DSAccess TopoCreateTimeoutSecs registry parameter is non-default

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at http://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether the Directory Service Access (DSAccess) initialization time-out default has been changed:


If the Exchange Server Analyzer finds that the TopoCreateTimeoutSecs key exists and has a value greater than 0, a non-default configuration message is displayed.

At startup, DSAccess uses a discovery process to identify the Active Directory® directory service topology and assess the availability of domain controllers and global catalog servers. After startup is complete and every 15 minutes thereafter, DSAccess uses almost the same process to rediscover the topology and check for changes in server availability. By default, DSAccess initialization during startup must finish within one minute. Otherwise, DSAccess stops. One minute is generally long enough for DSAccess to initialize.


If you hard code the directory servers that are used by DSAccess, DSAccess bypasses the discovery process and checks for server suitability only.


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

To revert to the default configuration

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeDSAccess

  3. Delete the value called TopoCreateTimeoutSecs.

  4. Close the registry editor.

If this registry key is present, you should consider evaluating your network topology. If additional DSAccess initialization time is required in your organization, it could indicate a design or network problem. Quick and reliable access to domain controllers, especially global catalog servers, is necessary for optimal Exchange operation.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (http://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).

For more information about directory access, see Understanding and Troubleshooting Directory Access (http://go.microsoft.com/fwlink/?LinkId=39012).