DongHyeonkaandClaude Opus 5
b2963105a8
The keycloak project ended with four open questions that design could not
settle. A two-VM lab was built to answer them by measurement, and this is
that material: 26 experiments, 125 raw command outputs, 22 browser captures.
Follows the import procedure in README.md.
source/ the originating repository verbatim — 78 documents, 28 SVGs,
8 manifests, plus .source-revision recording the commit
final/ the SSOT
document.md 729 lines written from the 29 experiment documents, not
concatenated: what was predicted, what was measured, and
where the measurement itself was wrong
evidence/raw 125 outputs, flattened to <experiment>__<file> because
the originals collided (01-baseline.txt appeared three
times) and the audit only globs the top level
evidence/meta one per raw file; command and exitCode are null and the
README says why rather than inventing them
evidence/browser 22 captures
assets/ three diagrams through techviz
.techviz/ their VizSpecs
A separate project rather than an addition to keycloak: the B-layer answers
that project's four questions, but the A, C and D layers are about cluster
failure, SSO and operations, and one document.md should hold one subject.
The four question records there can point here through 관계.
Recorded rather than papered over: only three of the 28 diagrams were
remade. The repository forbids hand-drawn SVG and forbids titles inside the
canvas; all 28 originals carry both, so converting them is redrawing, not
reformatting. They stay in source/ and the gap is written into the document.
verify-pipeline.py passes. audit-records.py reports no issues.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A-4 — 노드 전원 차단 증거
2026-09-04 12:07–12:24 KST
해설: docs/experiment-a4-node-loss.md
| 파일 | 무엇을 보여주는가 |
|---|---|
01-baseline.txt |
차단 전 — 양쪽 Ready, PVC 가 kc-lab-2 에 못박혀 있음(재배치 불가의 원인), 외부 200 |
02-worker-node-killed.txt |
virsh destroy kc-lab-2 — 40초간 노드가 Ready 로 남아 있고 외부는 이미 000. 이후 503 |
03-state-during-loss.txt |
죽은 파드가 ready=true, 산 파드가 ready=false. up 은 정확히 0. unreachable taint |
04-eviction-timing.txt |
tolerationSeconds=300 — 5분 뒤 축출, 새 postgres 는 Pending |
05-recovery.txt |
FailedScheduling: didn't match PersistentVolume's node affinity, StatefulSet DESIRED=2 CURRENT=1. 노드 복귀 후 60초 |
06-control-plane-inventory.txt |
kc-lab-1 에 있는 것 목록 — Traefik replicas=1 |
07-control-plane-loss.txt |
virsh destroy kc-lab-1 — 외부 000, kubectl 불통. 그런데 crictl ps 로 보면 keycloak-0 은 Running |
08-control-plane-recovery.txt |
60초 만에 복귀 |
a4-up-dropped-per-node.png |
Grafana — up 이 노드별로 0 으로 떨어지는 구간. 12:18–12:23 은 0 이 아니라 데이터 없음(관측자가 같이 죽음) |
핵심 네 줄
- 쿠버네티스는 40초 동안 노드가 살아 있다고 말한다. 사용자는 이미 장애를 겪는 중이다.
- 죽은 파드의 상태는 화석이다.
ready=true인 파드가 꺼진 기계 위에 있다. - StatefulSet 은 대체 파드를 만들지 않고, PVC 는 재배치를 막는다. 사람이 개입해야 한다.
- 컨트롤 플레인 상실 ≠ 워크로드 상실. 컨테이너는 계속 돌고, 들어갈 문만 사라진다.