monitoring

HighNodeCPUFrequency

Meaning

This alert fires when a CPU frequency on a node exceeds 80% of the maximum frequency for more than 5 minutes.

Impact

High CPU frequency can indicate:

• High CPU utilization pushing the processor to higher frequencies
• Potential thermal issues causing frequency scaling
• Power management concerns affecting system stability
• Reduced CPU lifespan due to sustained high-frequency operation

Diagnosis

1. Identify the affected node and CPU:

   kubectl get nodes
   

2. Check current CPU frequency on the node:

   kubectl debug node/<node-name> -it --image=registry.redhat.io/ubi8/ubi
   

   Then run inside the debug pod:

   cat /proc/cpuinfo | grep -i "cpu mhz"
   

3. Monitor CPU utilization and temperature:

   kubectl top nodes
   

   kubectl top pods --all-namespaces --sort-by=cpu
   

   Check system temperature (if available):

   sensors
   

4. Review node resource allocation:

   kubectl describe node <node-name>
   

5. Check for CPU-intensive workloads:

   ps aux --sort=-%cpu | head -20
   

Mitigation

1. Immediate actions:
   • Monitor the CPU temperature to ensure it’s within safe limits
   • Check if the high frequency is due to legitimate high CPU demand
   • Verify CPU settings if needed
2. If caused by high CPU utilization:
   • Identify and analyze CPU-intensive pods
   • Consider redistributing workloads across nodes
   • Evaluate pod resource limits and requests
   • Scale horizontally if needed
3. If thermal throttling is suspected:
   • Check system cooling and ventilation
   • Monitor ambient temperature
   • Consider reducing workload temporarily
   • Verify proper thermal management settings

If you cannot resolve the issue, see the following resources:

• OKD Help
• #virtualization Slack channel

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