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-3 — DB 강제 종료와 데이터 손실 증거
2026-09-04 12:00–12:05 KST · Keycloak 26.7.0 / PostgreSQL 16
해설: docs/experiment-a3-database-crash.md
| 파일 | 무엇을 보여주는가 |
|---|---|
01-crash-injection.txt |
첫 시도 실패 — 파드 안 백그라운드 루프가 exec 종료와 함께 죽어 0건 수집 |
02-design-check.txt |
핵심 설계 확인 — 로그인 트랜잭션도 SET LOCAL synchronous_commit TO OFF 로 커밋한다 |
03-loss-measurement.txt |
--grace-period=0 --force 주입 |
04-comparison.txt |
유실 0건 — 그러나 crash recovery 가 안 돌았다. 죽인 적이 없는 것 |
05-true-crash.txt |
kill -9 1 시도 — 컨테이너 안에서 PID 1 은 SIGKILL 을 무시한다 |
06-backend-kill-crash.txt |
성공한 주입 — 백엔드에 SIGKILL → not properly shut down / redo starts / redo done |
07-loss-result.txt |
결과: 153건 중 4건 유실. 토큰은 발급됐는데 세션 행이 없는 sid 목록 |
핵심 세 줄
- 로그인도 비동기 커밋이다. refresh 시각뿐 아니라 로그인 자체가 사라질 수 있다.
- 153건 중 4건(약 2.6%) 유실 — 초당 19건 기준 마지막 0.2초 분량,
wal_writer_delay기본값과 일치. - 주입을 세 번 시도해 세 번째에 성공했다. 앞의 둘은 "손실 0"으로 보였지만 실제로는 크래시가 아니었다.