A Postgres store names divergence between its clock and this host's, and decides nothing by it - #136
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…and decides nothing by it SPEC-v0.7 item 1 (§3, §8.1 T209 to T219, G13). PostgresStateStore measures its server's clock against the application's in one round trip, at open and when an expired lease is declared AMBIGUOUS (at most once per DEFAULT_LEASE). Half the round trip is the bound, and only skew past threshold plus bound is reported, so latency alone never is. The latest measurement is kept as the optional, read-only clock_skew attribute, a ctrlrun.state.ClockSkew. Control reads it at the start of execute and resume and after an AmbiguousEffect, uses it only if it is a ClockSkew, and appends CLOCK_SKEW_DETECTED once per new exceeded measurement. clock_skew_threshold defaults to one second, accepts up to DEFAULT_LEASE, and no value turns the measurement off. It observes and reports. Every lease is evaluated against the application clock exactly as at 0.6.1, no reservation outcome changes, and no store write changes; a measurement that fails is logged and changes nothing. T213 checks the decisions and the records against plan_reservation and a SQLite store. Verify gains G13 under ctrlrun.guarantees/v3: graded against a Postgres --store-url, N/A on SQLite with its sentence. The store conformance suite gains a clock case with four broken-store fixtures, not_applicable on SQLite and the in-memory store; SPEC-v0.6 T141 is amended to admit it. Also fixed: PostgresStateStore.events() read a NULL action_id back as the string "None", which the at-open event exposed and T217 caught.
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Included review availability: Your plan provides up to 1 included review per hour; 0 remain after this review. 📝 WalkthroughWalkthroughThe change adds Postgres clock-skew measurement, ChangesClock skew detection
Priority: ➖ Normal Estimated code review effort: 4 (Complex) | ~60 minutes Change: Feature Sequence Diagram(s)sequenceDiagram
participant Control
participant PostgresStateStore
participant PostgreSQL
participant EventSinks
Control->>PostgresStateStore: execute or resume
PostgresStateStore->>PostgreSQL: read server clock
PostgreSQL-->>PostgresStateStore: server timestamp
PostgresStateStore-->>Control: expose clock_skew
Control->>EventSinks: append CLOCK_SKEW_DETECTED
Merge Risk: ⚪ Minimal · up to The reviewed change has no identified merge-blocking risk. 🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
Full details: Docstring CoverageExplanation Docstring coverage is 41.61% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 161 functions across 14 files. (1 skipped: 1 unsupported.)
✨ Finishing Touches 💡 1📝 Generate docstrings 💡
🧪 Generate unit tests (beta)
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Inline comments:
In `@src/ctrlrun/conformance/store/suites.py`:
- Around line 1837-1841: Update the skew injection and validation around
_clock_skew_of so the initial offset accounts for the measurement bound rather
than only SKEW_MARGIN. If the returned ClockSkew has a larger bound and
measured.exceeded is false, retry backend.open_with_clock with an increased
offset based on that bound before returning failed; preserve the existing
failure handling for unresolved measurements and genuine non-exceedance.
In `@src/ctrlrun/control.py`:
- Around line 1834-1844: Update the clock-skew reporting flow around
_store.append_event so append failures are caught and do not propagate into
execute, resume, _secure, or _observe_secure. Set _skew_reported only after a
successful append, allowing failed reports to be retried, and preserve the
existing _fan_out call for successfully stored events.
In `@src/ctrlrun/verify/scenarios.py`:
- Line 2223: Update the skew-forcing logic around store_at so the offset exceeds
threshold plus the shifted store’s measured bound, rather than adding only one
second. If the measured bound cannot establish sufficient divergence, report
that the scenario could not do so instead of treating the absence of an event as
a failure.
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.github/workflows/ci.ymlCHANGELOG.mddocs/SPEC-v0.6.mddocs/SPEC-v0.7.mdsrc/ctrlrun/conformance/store/__init__.pysrc/ctrlrun/conformance/store/fixtures.pysrc/ctrlrun/conformance/store/suites.pysrc/ctrlrun/control.pysrc/ctrlrun/postgres.pysrc/ctrlrun/receipt.pysrc/ctrlrun/state.pysrc/ctrlrun/verify/guarantees.pysrc/ctrlrun/verify/scenarios.pytests/test_clock_skew.pytests/test_store_conformance.pytests/test_verify.pytests/test_verify_action.pytests/test_verify_report.py
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…s fails nothing Three findings from the review of #136, each with its test first. The injection is sized against the bound, never fixed. A conforming store reports only past threshold plus bound, and the bound is half the round trip to the store, so G13 and the conformance case were grading the link: on a round trip slower than their margin a correct store stays silent, and the fixed margin called that silence a defect. Both now widen the injection from the bound the shifted store measured until a store honest within its bound would have to report it, retry a bounded number of times, and meet a report on the clock they meant to align, where the aligning measurement's own doubt could explain it, by aligning again rather than by a FAIL. A link they cannot outrun is verify's internal error, exit 3, and in the suite a failure whose reason names the link and says it is not a report the store failed to make. The rule is one definition in state.py so the two cannot drift apart, and it recomputes exceedance from the measurement's fields rather than reading `exceeded`, so a store whose `exceeded` always answers true is still caught by the control. The report's append is guarded. `append_event` can fail, and it sat unguarded, so a locked database would have raised out of `execute` before the action was decided, and out of the AmbiguousEffect handler in place of the refusal the caller was owed: an observation deciding an outcome. It is now logged once per store per kind like the read, and `_skew_reported` moves only after the store accepted the event, so a lost report is made by the next action that can store it and a sink is handed only an event that was stored. Tests inject real latency rather than simulating it: a 2.1 s round trip for G13, a store honest within a six second bound for the suite. SPEC-v0.7 §12.1 records both arguments.
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Sep 11, 2026
…transcripts CTRLRun/ctrlrun#136 added the clock-skew guarantee and shipped without the docs half, so main was red on three generators and three suites. Generated, by running the generators: the schemas page gains CLOCK_SKEW_DETECTED, the 13 api pages follow the changed docstrings, and the readiness block goes 4,408 -> 4,586 tests and 11 -> 12 guarantees, pasted fresh into both docs.mdx and docs/production/index.mdx. The "No external security audit" line is unchanged; it is gated on v0.12, not on this release. Written, because no generator owns them: - docs/OWASP-AGENTIC-TOP10.md gains the G13 row. It maps to ASI08:2026 (partly) and to nothing else. What G13 closes is the silence, not the skew: a host running ahead marks AMBIGUOUS a record whose holder is mid-flight, a host running behind refuses too long, and neither said why. It changes no decision, does not synchronize anything, and a skew below the threshold is not reported. The row says all three. - docs/verify.md, docs/guides/verify-in-ci.mdx and docs/cookbook/verify-in-github-actions.mdx quote transcripts that are now wrong in three ways each: catalogue v2 -> v3, the G13 N/A line, and the count of what is not applicable. The first was regenerated from a real run; the other two match what the suite reproduces from their own policies. scripts/repoint-claims.py predates the repository split and never ran since: it looked for docs/docs/CLAIMS.md and resolved src/ctrlrun against this checkout, which has no src, so every citation silently skipped and it exited 0 having done nothing. It now reads docs/CLAIMS.md and CORE_ROOT, which is what let it re-point the 52 citations #136 shifted. The other seven pointed at control.py:1067, which was `except NotExecuted as exc:` and is now 1090; the repointer only searches for definitions, so those were moved by hand. Docs suite 1576 passed, nine generators and three audits clean.
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v0.7 item 1 (SPEC-v0.7 §3, G13). A Postgres store now measures its own clock against the application's and names the divergence. It decides nothing by it.
What it does
PostgresStateStorereadsclock_timestamp()at open, and again on the expired-lease (E3) path, rate-limited. It measures against the midpoint of two application readings and keeps the result as the optional read-onlyclock_skewattribute (actrlrun.state.ClockSkew).DEFAULT_LEASE, never off.Controlreads the attribute at the start ofexecuteandresume, and after an ambiguous refusal. It checks the value withisinstance(value, ClockSkew)and appendsCLOCK_SKEW_DETECTEDthrough its normal event path. A look-alike type or a read that raises is logged at WARNING once per store per kind, never raised.clock, caseskew-measured, with four broken-store fixtures. SQLite and in-memory stores share the application's clock, so the case is N/A there.ctrlrun verifygains G13 underctrlrun.guarantees/v3, with an aligned-clock positive control. On a store that reads the application's clock it is N/A with that reason.Observes and reports, and nothing else
Lease evaluation is unchanged:
v0.1 §5.3is not amended. No lease is decided differently, no reservation outcome changes and no store write changes. The only store additions are oneSELECT clock_timestamp()and keeping the result in memory. T213 checks every decision and every resulting record againstplan_reservation, and against a SQLite store driven through the same steps, with skew present. M37 (liveness judged on the store's clock) is caught by T213.Outside "observe only", for the maintainer
PostgresStateStore.events()read a NULLaction_idback as the string"None". EveryDELEGATION_*event on Postgres has named a proposal called "None" since that store shipped. T217 found it. The read path is fixed and nothing is written differently. It has its own test and a CHANGELOG Fixed bullet. It can be split into its own PR if you prefer.test_verify,test_verify_action,test_verify_reportand.github/workflows/ci.yml(AUTHORITY_NAis now 1,TEMPLATES_NAis now 6) count one more N/A.Evidence
scripts/check.sh: 2938 passed and 62 skipped without Postgres, 3006 passed with Postgres. The baseline was 2900/45 and 2951.now()instead ofclock_timestamp()) is an equivalent mutant, because both measurements run outside any transaction; it is recorded in §12.1.ctrlrun-docsPR. Thedocsjob is not a required check.Parallel branches
v0.7/2-transport(G12) andv0.7/3a-attempt-integritytouchverify/guarantees.py,postgres.pyandCHANGELOG.md. Whichever merges second rebases.Touches
src/: needs the maintainer's word to merge.Summary by CodeRabbit
New Features
CLOCK_SKEW_DETECTEDevent reporting.Bug Fixes
action_idvalues asNoneinstead of the string"None".Documentation