High CPU usage in Azure AD Connect Health for Sync

This article provides information about resolving an issue in which high CPU usage occurs in Azure Active Directory Connect Health for Sync.

Original product version:   Azure Active Directory
Original KB number:   4346822

Symptoms

You experience slow performance and high CPU usage (up to 100 percent) on a computer that runs the Azure Active Directory (Azure AD) Connect Health for Sync monitoring agent. In Task Manager, you notice that the Microsoft.Online.Reporting.MonitoringAgent.Startup  process is causing the high CPU usage.

Note

This issue is not limited to any specific Azure AD Connect Health versions or operating system versions.

Cause

This issue occurs because the June 2018 update for .NET Framework 4.7.2 is installed on the computer, and the Azure AD Connect Health for Sync monitoring agent does not fully support this update.

The following .NET Framework update would cause the high CPU issue by the monitoring agent.

.NET Framework update System version
KB4338420 Windows Server 2008
KB4338606 Windows Server 2008 R2
KB4054542 Windows Server 2012
KB4054566 Windows Server 2012 R2
KB4054590 KB4338814 KB4338419 KB4338605 KB4345418 General

Resolution

For Connect Health for AD DS and AD FS

To resolve this issue for Active Directory Domain Services (AD DS) and Active Directory Federation Services (AD FS), install the new Azure AD Connect Health agent version, 3.1.7.0, that was released in July 2018. The agent can be downloaded from Connect Health public documentation.

For Azure AD Connect

To resolve this issue for Azure AD Connect, install the latest version of Azure AD Connect.

Contact us for help

If you have questions or need help, create a support request, or ask Azure community support.