SAFETY-41: rate-limit the RISING EDGE, which is where the flood came from
checks / unit (pull_request) Successful in 5m9s

Review falsified the first version of this change, and the correction is
the substance of it.

Raising REASSERT_S 30 -> 150 removed NONE of the owner's notifications.
The re-assert interval governs only the still-engaged path; the rising
edge fired unconditionally. At the measured ~5 s cycle the live pattern -
48 engagements in ~25 minutes, about one cycle in six - leaves ~25 s of
clean cycles between engagements, past CLEAR_CYCLES x 5 s = 15 s. So the
alarm DE-ASSERTED between almost every engagement and each one returned
as a fresh rising edge. Measured on the shipped class over that window:
48 episodes, 48 notifications at REASSERT_S = 30, and still 48 at 150.

The interval now bounds the NOTIFICATION RATE rather than the repeat rate
within one episode: `last_alarm` survives a de-assert, and a new episode
speaks only if the interval has elapsed. Same window afterwards: 51
episodes, 51 engagements, 11 notifications.

⚠️ NOTHING IS DROPPED, AND THE TWO PROPERTIES THAT MATTER ARE PINNED:
  - a PINNED loop still speaks 6 times in the 900 s billing quarter,
    against a floor of 5 (part 2, unchanged);
  - a rising edge from a COLD watchdog still fires IMMEDIATELY, so a
    runaway beginning from quiet is never held back by a budget spent on
    an earlier, unrelated episode. That check is the counterfactual and it
    is the half that would go red if the limit ignored elapsed silence.
Every engagement is still counted, every episode still increments, and
the action-log row is still written on every engaged cycle. The budget is
on notifications, never on evidence.

The new pin is written in wall-clock seconds and in the shape the field
produced, so it does not move when the constant does. Verified by
reverting the rising edge to unconditional: 2 checks go RED naming it.

Full suite: 21 passed, 0 failed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
This commit is contained in:
glenn schrooyen
2026-09-05 17:06:29 +02:00
co-authored by Claude Opus 5
parent 1d393ced22
commit 8790c4d38f
2 changed files with 94 additions and 7 deletions
+45
View File
@@ -259,6 +259,51 @@ check(f"...and on no more than {MAX_FRACTION:.0%} of cycles (it was "
check("...while every single cycle is still counted",
pinned.engagements == int(QUARTER_S))
# --- THE SCATTERED REGIME, WHICH IS THE ONE THE OWNER ACTUALLY HIT -----------
# ⚠️ REVIEW-FOUND, SAFETY-41, and it falsified the first version of this card.
# The rising edge used to fire UNCONDITIONALLY, so REASSERT_S governed only the
# still-engaged path. A condition that engages and clears repeatedly therefore
# raised one notification PER EPISODE at any value of the constant.
#
# That is what the live install produced: 48 engagements in ~25 minutes,
# scattered about one cycle in six. At the measured ~5 s cycle the gaps are ~25 s
# of clean cycles, past CLEAR_CYCLES x 5 s = 15 s, so the alarm de-asserted
# between almost every engagement. Raising REASSERT_S 30 -> 150 removed NONE of
# them. The interval now bounds the notification RATE across episodes.
#
# The stimulus is written in wall-clock seconds and in the shape the field
# actually produced, so it does not move when the constant does.
SCATTER_CYCLE_S = 5.0
SCATTER_ONE_IN = 6
SCATTER_CYCLES = 305
scat = ClampWatchdog()
scat_alarms = sum(1 for i in range(SCATTER_CYCLES)
if scat.note(i % SCATTER_ONE_IN == 0, "scattered",
T0 + timedelta(seconds=SCATTER_CYCLE_S * i)))
_scat_span = SCATTER_CYCLE_S * SCATTER_CYCLES
print(f" scattered 1-in-{SCATTER_ONE_IN} over {_scat_span:.0f} s at "
f"{SCATTER_CYCLE_S:.0f} s cycles: {scat.episodes} episodes, "
f"{scat.engagements} engagements, {scat_alarms} alarm(s)")
check(f"a condition that de-asserts between engagements is rate-limited ACROSS "
f"episodes, not once per episode ({scat_alarms} alarms for "
f"{scat.episodes} episodes)",
scat_alarms < scat.episodes)
check(f"...and the rate honours the same interval the pinned case does: at most "
f"ceil({_scat_span:.0f}/{REASSERT_S:.0f}) + 1 = "
f"{int(_scat_span // REASSERT_S) + 1}",
scat_alarms <= int(_scat_span // REASSERT_S) + 1)
check("...while EVERY episode and EVERY engagement is still counted - the "
"budget is on notifications, never on evidence",
scat.episodes == scat.engagements == SCATTER_CYCLES // SCATTER_ONE_IN + 1)
# ⚠️ THE COUNTERFACTUAL. A runaway that begins from quiet must NOT be delayed by
# a budget spent on an earlier, unrelated episode - so a cold watchdog speaks at
# once, and this is the half that would go red if the rate limit were applied
# without regard to how long it has been silent.
check("...and a rising edge from a COLD watchdog still fires immediately, so a "
"runaway beginning from quiet is never held back",
ClampWatchdog().note(True, "cold runaway", T0) is True)
# --- THE HYSTERESIS, PINNED AGAINST THE CHATTER DIRECTION --------------------
# ⚠️ REVIEW-FOUND. This used to issue `range(CLEAR_CYCLES - 1)` clean cycles,
# which at CLEAR_CYCLES = 1 issues ZERO of them and passes while printing