Active Administrator 8.7 - User Guide

Domain controller CPU load

Domain controller CPU load

Indicates that the CPU for the domain controller is too busy, which may indicate a problem with directory service or it can indicate that a problem may occur because the domain controller cannot respond to requests quickly enough.

Data collector

•	Category: Performance Counters

•	Name: CPU Processor time

•	Supported on: Windows Server 2016, Windows Server 2019, and Windows Server 2022

•	Required permissions: When monitored locally and remotely, only domain user privilege is required and the user must be a part of the Performance Logs user group.

Description

The Directory Analyzer agent monitors the Processor\% Processor Time performance counter on the domain controller. If the value of the performance counter goes above the configured threshold for a period exceeding the configured duration, the agent will set this alert condition.

Increased CPU load is a result of running too many applications on the server, or running applications that require too much CPU time.

It is also possible that the CPU load has increased due to some pathological condition in a particular application. For instance, Active Directory® itself requires substantial CPU resources when it is processing inherited Access Control Lists (ACLs). Active Directory can also require a lot of CPU resources when it processes complex, non-indexed directory searches.

Resolution

First, try to determine if the increased CPU load is due to a particular program, or if it is due to running too many programs. Use a utility like Task Manager to inspect the CPU usage of all processes on the system. If there are several processes getting more than 10% of the CPU, then the problem is most likely due to running too many programs on the server. If possible, stop some of the programs.

If one process is using all of the CPU for an extended period of time, it may be due to a bug in the software, or it may be that the program just requires too much CPU. If possible, stop the program and run it on a different computer.

Domain controller page faults

Domain controller page faults

Indicates that the performance of the server may be degraded because of too many page faults.

Data collector

•	Category: Performance Counters

•	Name: Memory page faults a second

•	Supported on: Windows Server 2016, Windows Server 2019, and Windows Server 2022

•	Required permissions: When monitored locally and remotely, only domain user privilege is required and the user must be a part of the Performance Logs user group.

Description

The Directory Analyzer agent constantly monitors the Page Faults/sec performance counter on the domain controller. If this number exceeds the configured threshold, the agent will issue an alert.

A page fault occurs whenever the operating system tries to access a virtual memory page that is not currently in memory or is in the incorrect place in memory. The process requesting the page must wait while the operating system makes room for the requested page in memory and reads it from disk or relocates it, which may cause a significant delay for the faulting process. If many processes are causing page faults, a condition known as thrashing can occur. If this happens, the performance of the server goes to zero as the operating system spends most of its time managing memory and very little running applications.

A continuously high page fault rate is an indication that the server is running too many processes with insufficient real memory. If left unattended, Active Directory® performance will suffer greatly, and eventually the directory system agent (DSA) will be unable to service requests, which can result in failed logins and authentications, as well as the inability of some applications and services to run at all.

Resolution

First, determine if the page fault rate is too high or if the threshold is set too low. Assess the overall performance of the server while the page fault rate is high. If the performance seems adequate, increase the threshold; if the performance seems poor, try to reduce the page fault rate.

To reduce the page fault rate on the server, determine if the page faults are due to a single process or a combination of several processes.

1	Run the Windows NT Task Manager and open the Processes tab.

2	Select View | Select Columns.

3	Select Memory Delta and Page Fault Delta, if necessary.

4	Observe the numbers to determine if there is one process generating page faults, or if there are several.

If there is only one process, run that program on another server or at a different time when the server is not as loaded.

If there are several processes that are generating high page fault rates, you will either have to run some of them on another server, or you will have to add more RAM to the server.

Domain controller unresponsive