Showing posts with label high CPU. Show all posts
Showing posts with label high CPU. Show all posts

Wednesday, June 27, 2018

Azure Active Directory Connect, High CPU Usage After June 2018 Patching

I did the latest Microsoft security updates for some servers, and was noticing my server running Azure Active Directory Connect for Office 365 was running at very high CPU.  I wasn't successful at restarting it from within the guest (or, wasn't patient enough, take your pick) and reset the VM.  The issue persisted.

My Microsoft.Identity.Health.AadSync.MonitoringAgent.Startup.exe was running at 99%.

Some research quickly tipped me off to the culprit.  (https://social.msdn.microsoft.com/Forums/azure/en-US/e9b621f6-f38c-488e-8fcb-ff85d406f256/azure-ad-connect-health-sync-monitor-high-cpu-usage?forum=WindowsAzureAD) .NET Framework 4.7.2 was the culprit.  Uninstalling the right KB depends on your OS.

  • Server 2008 R2 - "Microsoft .NET Framework 4.7.2"
  • Server 2012 - KB4054542
  • Server 2012 R2 - KB4054566
  • Server 2016 - KB4054590
I was dealing with Server 2016, so I uninstalled KB4054590, restarted, and the server seems fine.


I'll be sure to monitor the version history to see if when I go to patch next month, if Azure Active Directory Connect has been updated to address this.