Sixth review - the first against the interval architecture - verdict:
the architecture holds (idempotence, order-independence, 4-process
concurrent-writer safety, rollback immunity, format consistency, and a
120-permutation order sweep all verified), with ONE high finding, which
I had independently reproduced while the review ran: the FORWARD clock
adversary was unhandled, and unlike every other failure mode in this
subsystem it failed OPEN.
The 'obs' mark is a MAX-upsert - monotonic in the leak direction. One
glitched-forward sample (NTP flap reading 2099) while consented dragged
last_confirmed_at to 2099; a later revoke stamped closed_at = 2099; the
closed window then CONTAINED every refused period that followed. Both
the reviewer and I reproduced refused packages becoming gate-eligible.
The rollback twin was mutation-tested since round 5; nobody had asked
whether the mirror image existed.
Two clamps, each covering what the other cannot:
- The obs mark advances at most MAX_OBS_ADVANCE_SECONDS (30 days) per
call. Honest heartbeats never bind it; a machine off for months
catches up in a few hook fires (fail-closed latency only); one insane
sample moves the horizon by a bounded step that real time overtakes.
- A close is MIN(last_confirmed_at, closing observation's raw stamp).
Confirmed-time keeps unobserved gaps out of windows (v1's leak); the
raw stamp lets an honest clock at revoke time pull a poisoned horizon
back to the true revoke moment. A rolled-back clock at close time
only closes earlier - fail-closed.
Also from the review:
- D2: the data-mark advance in the REAL package writer had no coverage
(the harness re-implemented the insert; deleting the production line
survived 314 tests). Now driven through create_and_export_package_if_due.
- D3: the "don't create ~/.hermes/telemetry for fully-disabled users"
skip was dead code - the store constructor creates the directory
before the exists() check ran. The probe now checks the default path
without constructing; verified empirically on a fresh HERMES_HOME.
- Upgrade note in A.4: pre-interval backlog is never transmitted after
upgrade (fail-closed; deliberate).
New harness scenarios: forward-poison-then-revoke (the leak), and
forward-poison-cannot-wedge (the cap). Mutation check: unclamping the
close, removing the cap, and removing the real writer's data-mark
advance each fail the suite.
273 tests pass; ruff and windows-footguns clean; staging E2E 202.
Ben Barclay
67d152bc7e