OLE Automation objects are not supported in fiber mode.

Product: SQL Server
Event ID: 8149
Source: MSSQLServer
Version: 8.0
Component: SQL Engine
Message: OLE Automation objects are not supported in fiber mode.
Fiber mode, also known as lightweight pooling, is not a supported SQL Server configuration option if you use OLE Automation objects.

By default, SQL Server uses one thread per active SPID or user process. These threads work in a pooled configuration to keep the number of threads manageable. The advanced configuration option lightweight pooling (which is sometimes referred to as “fiber mode”) uses Windows NT “fiber” support to handle several execution contexts with a single thread.

You do not need to use fiber mode except in very rare circumstances. Lightweight pooling is only even potentially useful if all of the following conditions are met. You still must determine if it is actually useful through careful controlled testing:

  • Large multiprocessor servers are in use.
  • All servers are running at or near maximum capacity.
  • A lot of context switching occurs (greater than 20,000 per second).

For more information about how to determine the proper SQL Server configuration settings, see Microsoft Knowledge Base article 319942.

User Action
Turn off the lightweight pooling option.

exec sp_configure ‘show advanced’, 1
exec sp_configure ‘lightweight pooling’, 0

The setting takes effect after stopping and restarting the SQL Server instance.


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