Knowledge Base

Check CPU Affinity Settings

When CPUs are not correctly assigned to important processes like the Video Web Service and the RabbitMQ message service, NoldusHub functionalities will fail.

Solution: To resolve issues due to sub-optimal CPU affinity settings, first check whether CPU affinity settings are applied correctly. If the settings are not applied correctly, restart the NoldusHub services with StopNoldusHub.bat and then StartNoldusHub.bat.

NoldusHub Services

The following file contains the actual CPU affinity settings on the NH server:

C:\Program Files\Noldus\NoldusHub\Scripts\Control-NoldusHub.ps1

Look for a section like this:

• $Env:AffinityMaskVws = Calculate-AffinityMask 0 62.5
• $Env:AffinityMaskRmq = Calculate-AffinityMask 62.5 100
• $Env:AffinityMaskFes = Calculate-AffinityMask 62.5 100

The settings mean that Vws gets the first 62.5% of the CPU cores. If your server has 32 cores, Vws (Noldus.VWS.Service.exe) will get CPU cores 0–19. RabbitMQ (Rmq: erl.exe) will get CPU cores 20–31 and Fes (Noldus.FacialExpressionService.exe) will also get CPU cores 20–31. All other services should use all CPU cores.

Correct Number of CPU Cores

1. Open Task Manager and locate the NoldusHub service you want to check.
2. Open the affinity settings via the context menu by selecting Set Affinity.
3. Check if the service has the correct number of CPU cores assigned.
4. Verify that really the first or the last CPU cores are selected, as expected.

Source: NoldusHub 1.7 Tips and Tricks, Noldus Information Technology