VM child alarms auto-clear when parent ESX host alarm clears in Spectrum VHM

Products

• Network Observability
• Spectrum

Issue/Introduction

In DX NetOps Spectrum, when using the VMware vCenter integration (Virtual Host Manager), child alarms (such as VM Contact Lost) that are suppressed under a parent alarm (such as ESX Host Down) may clear automatically when the parent alarm is resolved. This occurs even if the underlying child device is still unreachable.

Foe example, during a parent outage (e.g., ESX host down), child VMs generate "Contact Lost" alarms. Spectrum's correlation engine hides these under the parent probable cause (e.g., `0x56e000c`). When the ESX host recovers, the hidden child alarms (probable cause `0x10009`) clear automatically, changing the VM condition to "Normal," even if the VM agent has not recovered.

Environment

• DX NetOps Spectrum (All Versions)
• Virtual Host Manager (VHM) / VMware vCenter Integration

Cause

This is the default design of Spectrum's Root Cause Analysis (RCA). When a parent alarm is cleared, Spectrum clears all associated "impact" or "suppressed" child alarms to prevent stale alerts.

Resolution

To ensure child alarms only clear after independent confirmation of reachability:

1. Use Condition Correlation Editor: Create a custom rule in the Condition Correlation Editor to define specific recovery criteria for the child model. This allows the child alarm to remain active until a successful poll is verified.
2. Modify Event Configuration:
   • Open the Event Configuration Editor.
   • Locate the VM Contact Lost alarm (Probable Cause 0x10009).
   • Identify the recovery event that clears this alarm.
   • Modify the correlation logic so that the clear action is only triggered by the specific VM's recovery event (e.g., 0x1000a) rather than the parent's recovery.

Additional Information

For detailed steps on custom correlations, see the [Condition Correlation Documentation](https://techdocs.broadcom.com/us/en/ca-enterprise-software/it-operations-management/spectrum/24-3/managing-network/condition-correlation.html).

If further assistance is needed, see [Contact Support](https://support.broadcom.com/web/ecx/contact-support). Scroll to the bottom of the page and click on your respective region to speak with a customer representative or a Support Engineer.