All the Host's in vCenter are intermittently showing "Not Responding" state

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• All the ESXi hosts in vCenter intermittently display a "not-responding" status, only to automatically reconnect after a short period.
• Concurrently, there are certain hosts, particularly those recently decommissioned but not removed from vCenter inventory, remain perpetually in a "not-responding" state.
• vpxd.log records multiple "Missed Heartbeats" for the Host's

Environment

VMware vCenter Server 7.0.x

VMware vSphere ESXi 7.0.x

Cause

When ESXi hosts are decommissioned but remain in vCenter inventory, the vCenter Server continuously expends resources attempting to communicate with them resulting in missed heartbeats. This unnecessary load can cause active hosts to appear disconnected.

Resolution

Disconnect the decommissioned Host's followed by removing them from inventory.