← 문제 라이브러리
Network Intermediate NETWORK-006 · 20 min

Only the load balancer health check is blocked by the firewall, dropping the whole service

A situation where the application is fine but a different health-check path policy drains all traffic.

무료
시나리오

A scenario that narrows down the root cause, centered on checking the policy difference between production traffic and health-check traffic, in the situation of only the load balancer health check being blocked by the firewall and dropping the whole service.

먼저 볼 것
  • Identify the primary failure signal in the Firewall Policy scenario.
  • Separate visible symptoms from the underlying technical dependency.
  • Describe the safest recovery path and the follow-up prevention work.
점검 체크리스트
  1. Summarize the current impact and the last known change.
  2. Collect direct evidence from logs, runtime state, and configuration before changing anything.
  3. Separate immediate recovery from permanent prevention work.
복구와 재발 방지

Choose the smallest safe recovery action first, then record the prevention work that reduces repeat incidents.

같이 보면 좋은 질문
Why can the service look healthy to users but still fail overall?

If health checks are blocked, the load balancer can remove every backend even while direct node access still works.