Scenario
Only one node drops service traffic after a high-churn rolling update on a Cilium cluster.
A Cilium upgrade finishes and one node still drops service traffic because the BPF map pinned the old backend slot after endpoint churn
The service is healthy, but one node keeps selecting a retired backend slot in its pinned BPF state.
What to check first
- Identify the primary failure signal in the The Upgrade Ended Cleanly and One Node Kept Calling the Backend Seat Number That Had Already Been Removed From the Chart scenario.
- Separate visible symptoms from the underlying technical dependency.
- Describe the safest recovery path and the follow-up prevention work.
Checking checklist
- Summarize the current impact and the last known change.
- Collect direct evidence from logs, runtime state, and configuration before changing anything.
- Separate immediate recovery from permanent prevention work.
Recovery and prevention
Inspect pinned BPF service maps before widening timeouts or recreating the service.
Questions worth viewing together
No. Keep commands, logs, file names, APIs, and product names unchanged, then explain the reasoning in the selected UI language.
State the root cause, the evidence that supports it, and the safest recovery direction.
The source scenario is treated as an incident artifact. Guidance, checklist, hints, and explanations can be localized around it.
Similar cases seen in the field