Performance Tuning Wins and DHCP

ID: Q199160

The information in this article applies to:

Microsoft Windows NT Server version 4.0

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.

SUMMARY

The Microsoft Windows NT Windows Internet Name Service (WINS) and Dynamic Host Configuration Protocol (DHCP) services are usually limited in performance by the disk subsystems that hold their databases. This article discusses how to improve the performance of these services.

MORE INFORMATION

The Microsoft WINS and DHCP service use the Microsoft Jet database engine. The Jet database engine is a high performance system that provides reliable transaction processing by confirming to WINS or DHCP that it has positively written data to disk. This requires a mechanical operation to be performed and confirmed for each database operation. If the database is flooded with transactions, the performance of the service will be blocked while waiting for the confirmation of disk writes. Therefore, highest performances can only be achieved using a high performance hard disk subsystem.

When selecting a disk subsystem, these general rules should be followed:

SCSI is preferable to IDE.

Fast wide SCSI is preferable to narrow/standard SCSI.

RAID level 5 is preferable to a single disk.

A hardware-based RAID controller is preferable to software RAID.

More spindles are preferred over fewer spindles, to distribute writes.

A caching disk controller is preferable to a noncaching controller, but a caching controller must have a battery backup to ensure data integrity.

In all cases, Microsoft recommends consulting the Windows NT Hardware Compatibility List (HCL) for computers and subsystems that are certified to run with Windows NT.

It is important to stress that a caching controller must have a battery backup, because not having one creates the possibility that a controller will confirm to the file system that it has successfully written to disk without the write being performed. If there is a loss of power or other catastrophic failure, the transaction may be lost. Caching controllers with battery backup will commit cached transaction to disk when the disk subsystem is restarted, allowing the database to be consistent with transactions that have been confirmed.

Another optimization that is available to WINS, but currently not to DHCP, is the manual configuration of a log file path. As a performance optimization, the Jet database engine quickly writes transaction log files to disk that are then later written (committed) to the main database file when time permits. By configuring the log file path to a different disk subsystem than the main database file, further optimization can be achieved.

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).

The logfile path is configured in the Windows NT registry under the following key:


   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Wins 
   \Parameters\LogFilePath

   Data Type: REG_SZ or REG_EXPAND_SZ
   Range: Directory
   Default: %SystemRoot%\System32\WINS

This key should only be configured if the specified log file path points to a directory on a high performance subsystem, as writing to log files is usually the bottleneck in Wins server performance.

REFERENCES

For additional information, please see the following article(s) in the Microsoft Knowledge Base:

Q188027 Performance, Audit Logging, and Fixes to the DHCP Service

Q184693 DNS/DHCP/WINS Release Notes for Windows NT 4.0 SP4 Update

Keywords :
Version : winnt:4.0
Platform : winnt
Issue type : kbinfo