시나리오
A check on port 5432 of two DB servers: `nc -vz db-a 5432` fails at once with 'Connection refused'; `nc -vz -w 10 db-b 5432` fails after 10 seconds with 'timed out'.
Connection refused vs connection timed out: what is the difference?
Use the kind of connect error to decide where the connection stopped.
단서
구독하면 이어서 볼 수 있어요
이 문제의 전체 시나리오와 점검 체크리스트, 복구 순서, 모범 풀이는 Pro 구독에서 열립니다.
먼저 볼 것
- Understand the main investigation order for Network incidents.
- Separate user-facing symptoms from the deeper technical cause.
- Describe both quick recovery actions and follow-up improvements.
점검 체크리스트
- Summarize the symptom and the current impact first.
- Check recent changes before collecting deeper diagnostics.
- Verify config, runtime state, and recovery path in order.
복구와 재발 방지
Write down the minimal recovery path first, then capture the improvements that reduce repeat incidents.
같이 보면 좋은 질문
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.
현장에서 본 비슷한 케이스