MaxConcurrentAPI Script for Netlogon Issues

I get incidents from time to time that deal with Netlogon Service Issues. For example: Semaphore Waiters, Semaphore Timeouts, Semaphore Acquires, etc…

Here is a script I got from the Microsoft Gallery
In some enterprise environments the sheer volume of NTLM authentication can produce performance bottlenecks on servers. To help make the problem easier to detect, this PowerShell script was written.

Execution:

Now, I modified this script taking out the clear screen parameter so that I could be run against multiple servers. Place the script in your Scripts directory and name it CheckMaxConcurrentApiScript.ps1

First, in PowerShell, gather your list of servers:

Or

Next, run the command to run the ps1 against those servers:

Or

Sample Output:

DC03
Detection Time : 12/13/2018 7:56:16 PM
Problem Detected : False
Server Name : DC03
Server Role : Domain Controller
Domain Name : ldlnet.org
Operating System : Microsoft Windows Server 2008 R2 Enterprise
Time Since Last Reboot : 4 days 22 hours
Current Effective MaxConcurrentApi Setting : 10
Suggested MaxConcurrentApi Setting (may be same as current) : 10
Current Threads in Use (Semaphore Holders) : 0
Clients Currently Waiting (Semaphore Waiters) : 0
Cumulative Client Timeouts (Semaphore Timeouts) : 17
Cumulative MaxConcurrentApi Thread Uses (Semaphore Acquires) : 3493999
Duration of Calls (Avg Semaphore Hold Time) : 0

EXCH02
Detection Time : 12/13/2018 8:00:53 PM
Problem Detected : False
Server Name : EXCH02
Server Role : Member Server
Domain Name : ldlnet.org
Operating System : Microsoft Windows Server 2008 R2 Standard
Time Since Last Reboot : 4 days 23 hours
Current Effective MaxConcurrentApi Setting : 10
Suggested MaxConcurrentApi Setting (may be same as current) : 10
Current Threads in Use (Semaphore Holders) : 0
Clients Currently Waiting (Semaphore Waiters) : 0
Cumulative Client Timeouts (Semaphore Timeouts) : 570
Cumulative MaxConcurrentApi Thread Uses (Semaphore Acquires) : 1682257
Duration of Calls (Avg Semaphore Hold Time) : 0

Hopefully, this script will assist you with gathering the needed information to help you balance the netlogon load between your servers when needed in your environment.

HAPPY TROUBLESHOOTING!

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