Monitoring Performance in Active Directory

Database Object

The Database object relates to the Extensible Storage Engine (ESENT), the transacted database system that stores all Active Directory objects. This performance object is not installed by default. The counters on the Database object enable you to perform advanced tuning of Active Directory. You can also use some of the counters to help determine whether you need more disk drives for storage of logs or database.

Currently, there is no automated way to install the performance dynamic-link library (DLL), Esentprf.dll, in Windows 2000.

Caution

Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.

To load the Database object

Copy the performance DLL (Esentprf.dll) located in SystemRoot\System32 to any directory (for example, C:\Perf).
Run Regedt32.exe or Regedit.exe, and make sure that the following registry subkeys exist:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ESENT

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ESENT\Performance

If these subkeys do not exist, you need to create them.

For more information about creating registry subkeys, see Windows 2000 Server Help.
Make sure that, under the Performance subkey, the registry values that have the following settings exist:
- Open : data type REG_SZ : OpenPerformanceData
- Collect : data type REG_SZ : CollectPerformanceData
- Close : data type REG_SZ : ClosePerformanceData
- Library : data type REG_SZ : c:\perf\esentprf.dll
Change directory to SystemRoot\Winnt\System32 or to another folder that contains the files Esentperf.ini and Esentperf.hxx generated when Eseperfnt.dll was compiled.
(Optional) To verify that previous counter information is not present in the registry, at the command prompt, type unlodctr.exe ESENT.
To load the counter information into the registry, run Lodctr.exe Esentperf.ini.

To view the counters for the Database object, restart System Monitor.

Table 8.2 lists the performance counters for the Database object.

Table 8.2 Additional Active Directory System Monitor Counters Under the Database Object

Counter	Description
Cache % Hit	The percentage of page requests for the database file that were fulfilled by the database cache without causing a file operation. If this percentage is too low, the size of the database cache might be too small. You can increase the size of the database cache by adding more RAM.
Cache Page Fault Stalls/sec	The number of page faults (per second) that cannot be serviced because there are no pages available for allocation from the database cache. If this counter is nonzero most of the time, the clean threshold might be too low. You can increase the size of the database cache by adding more RAM.
Cache Page Faults/sec	The number of page requests (per second) for the database file that require the database cache manager to allocate a new page from the database cache. If this number is too high, the size of the database cache might be too small. You can increase the size of the database cache by adding more RAM.
Cache Size	The amount of system memory used by the database cache manager to hold commonly used information from the database file or files to prevent file operations. If the size of the database cache seems to be too small for optimal performance and there is very little system memory available on the system, adding more RAM to the system might increase performance. If there is plenty of system memory available and the database cache size is not growing, the database cache size might be restricted to an artificially low limit. You can increase the size of the database cache by adding more RAM.
File Bytes Read/sec	The number of bytes that are read (per second) from the database file or files into the database cache. If this rate is too high, the size of the database cache might be too small. You can increase the size of the database cache by adding more RAM.
File Bytes Written/sec	The number of bytes that are written (per second) to the database file or files from the database cache. If this rate is too high, the size of the database cache might be too small. You can increase the size of the database cache by adding more RAM.
File Operations Pending	The number of reads and writes issued by the database cache manager to the database file or files that the operating system is currently processing. A large number of pending operations increases system throughput, but also increases the time required to process individual operations. Typically, a larger number means that file operations on the database file or files might be a bottleneck.
File Operations/sec	The number of reads and writes (per second) issued by the database cache manager to the database file or files. If this number is too high, the database cache size might be too small. You can increase the size of the database cache by adding more RAM.
Log Record Stalls/sec	The number of instances (per second) that a log record cannot be added to the log buffers because the buffers are full. If this counter is not zero most of the time, the size of the log buffer might be a bottleneck.
Log Threads Waiting	The number of threads waiting for their data to be written to the log in order to complete an update of the database. If this number is too high, the log might be a bottleneck.
Log Writes/sec	The number of instances (per second) that the log buffers are written to the log file(s). If this number approaches the maximum rate at which the medium that is storing the log file(s) can write data, the medium might be a bottleneck.
Table Open Cache % Hit	The percentage of database tables opened by using cached schema information. If this number is too low, the size of the table cache might be too small. You can increase the size of the database cache by adding more RAM.
Table Open Cache Hits/sec	The number of database tables opened (per second) by using cached schema information. If this number is too low, the size of the table cache might be too small. You can increase the size of the database cache by adding more RAM.
Table Open Cache Misses/sec	The number of database tables opened (per second) without using cached schema information. If this number is too high, the size of the table cache might be too small. You can increase the size of the database cache by adding more RAM.
Table Opens/sec	The number of database tables opened per second.

Note

When the description of a counter indicates that the number counted is "too high" or "too low," it is an indication of how to adjust the system configuration. For example, if you make a change that increases the rate of page faults for a cache, you know that you have made an incorrect adjustment, and you must change the settings in the opposite direction. Please note that you cannot adjust settings that cause the counter behavior to change in System Monitor. Settings are configured elsewhere, such as in the registry or in startup .inf files.