SafeOps Academy

Quiz: Chapter 08 (Availability Engineering)

Questions

  1. Why is HPA alone not sufficient to guarantee safe disruption handling?

  2. What does a PodDisruptionBudget control?

  3. Which signal must be checked before node drain?

  4. If Allowed disruptions = 0 for a critical service, what is the correct action?

  5. Which statement is correct?

  • A) PDB affects all pod failures including OOM and crashes.
  • B) PDB controls voluntary disruptions such as evictions/drains.
  • C) HPA ignores resource metrics.

  1. What does ScalingLimited=True typically indicate in HPA status?

  2. Why keep minReplicas > 1 in staging/production for critical services?

  3. Preferred rollback path for bad availability config:

  • A) patch random live objects
  • B) revert Git manifests and let Flux reconcile
  • C) disable autoscaling and PDB permanently

  1. Can HPA scale if metrics are unavailable?

  2. Complete the guardrail:

  • A) drain first, verify later
  • B) verify HPA + PDB state first, then perform disruption
  • C) remove PDB to speed up maintenance

Answer Key (Short)

  1. HPA scales capacity; it does not enforce safe eviction/disruption rules.
  2. Voluntary disruption budget for selected pods.
  3. PDB Allowed disruptions (plus HPA/replica readiness).
  4. Stop and adjust capacity/budget first.
  5. B
  6. Desired scale is capped by min/max bounds or target constraints.
  7. Preserves service continuity during rollout/drain events.
  8. B
  9. Not reliably; autoscaling decisions depend on available metrics.
  10. B