IMPORTANT: This article contains information about modifying the registry. Before you
modify the registry, make sure to back it up and make sure that you understand how to restore
the registry if a problem occurs. For information about how to back up, restore, and edit the
registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry
SYMPTOMS
The Directory service stops responding (hangs) and logs the following error message in the event log:
Event ID: 1186
Source: MSExchangeDS
Type: Error
Category: Replication
Description: The internal directory replication agent (DRA) Dispatcher
thread is waiting in a remote procedure call (RPC) to directory XXXX. The directory has attempted to cancel the call and recover the thread, with status 0x0. If this condition persists, stop and restart that Microsoft Exchange Server computer.
WORKAROUND
To work around this behavior, restart the server that is experiencing the error, as well as the server that is specified in the text of the event. This works only if you find and resolve the underlying cause of the behavior (for example, saturated network links). The client may also need to look into breaking up large distribution lists.
If the problem persists after you restart both servers, you can change the behavior of the DRA by modifying the following registry values:
- Directory Replication Timeout
- Max Threads
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may
require you to reinstall your operating system. Microsoft cannot guarantee that you can solve
problems that result from using Registry Editor incorrectly. Use Registry Editor at your own
risk.
Directory Replication Timeout
You can change the default directory replication timeout value by adding the following key into the registry:
- Start Registry Editor (Regedt32.exe).
- Locate the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeDs\Parameters
- On the Edit menu, click Add Value, and then add the following registry value:
Value Name: Replicator async thread check (minutes)
Data Type: REG_DWORD
Value: 35 (Dec,default)
- Quit Registry Editor.
NOTE: Increase this value in increments of 30 until you no longer receive the error message.
Max Threads
To increase the number of threads available for directory replication, adjust the following parameter:
- Start Registry Editor (Regedt32.exe).
- Locate the Max Threads value under the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ MSExchangeDS\Parameters\Max Threads (EXDS+NSP+DRA)
- Click the Max Threads value.
- On the Edit menu, click DWORD.
- In the Data field, type 200 (Dec), and then click OK.
- Quit Registry Editor.
This action increases the number of threads available from the default of 50 to 200. You may need to adjust this value for best results.