During "Scan Entity" task running on vCenter server, overall appliance CPU utilization reaches 100% and remain stuck

Products

• VMware vCenter Server

Issue/Introduction

• Using vCenter server UI, when performing bulk ESXi host remediation task at "Datacenter level",  overall vCenter server CPU utilization will reach upto 100% and will remain stuck.

• This will affect overall vCenter server performance and accessibility.
• And "Remediate Entity" task will also get stuck

• "top" command output  (using vCenter server SSH session) on vCenter server showcasing all vCPUs utilizing upto 100% of CPU cycles:

Environment

vCenter server 8.0 U3

Cause

• Datacenter server level remediation task will initiate the remediation of all of the underlying ESXi hosts at once.

• It might cause heavy CPU utilization of vmware-updatemgr (Update Manager) service on vCenter server.

"vimtop" command outcome (using vCenter server SSH session) showing "Update Manager" service utilizing heavy CPU: 

Resolution

Workaround:

• Cancel the remediation task. After cancellation, overall CPU utilization at appliance level will be normalized in few minutes.
• Perform the ESXi host remediation at "Cluster level" or try to lower down the total number of Hosts to remediate (i.e. rather remediating all the ESXi hosts together, try to remediate few set of ESXi hosts at a time)

 

Additional Information

Remediate ESXi Hosts Against a Single Baseline or Multiple Baselines