Fix for Loss of Data Records or Partial Records Written to Disk Problem

Internet Information Server (IIS) 3.0 logging supports periodic flushing of log file data to disk. By default this interval is five minutes, however you can modify this setting by changing the following registry entry:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\InetInfo \Parameters\LogFileFlushInterval

NOTE: The above registry key is one path; it has been wrapped for readability.

In certain circumstances, data may be lost if the buffer is prematurely flushed. Overall, this leads to a loss of data records or partial records written to disk.

This problem occurs if the lock that protects file data in the periodic flush path is not acquired. This problem happens specifically in the case where the log flush size registry value is set to a large buffer size (for example, 32MB instead of the default 64k).

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\InetInfo \Parameters\LogFileBatchSize

NOTE: The above registry key is one path; it has been wrapped for readability.

The fix is to acquire the file-data lock and hence protect against premature flushes or loss of log data.

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
This problem does not occur in Internet Information Server version 4.0.

Microsoft has confirmed this to be a problem in Internet Information Server version 3.0. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.