Files
FabledSteward/tests/core/test_alert_no_data.py
T
bvandeusenandClaude Opus 5.5 c368e93e2c
CI / lint (push) Successful in 2s
CI / unit (push) Failing after 1m14s
CI / integration (push) Successful in 1m14s
CI / publish (push) Skipped
feat(alerts): silence is alertable — agent offline and no-data (#5062)
Agent offline is an ordinary rule now. The host_agent scheduler records
host_agent/<host>/seconds_since_seen every minute (from last_seen_at, or
registration time for an agent that never reported), replacing the task
that only logged stale agents. The catalog offers the metric, and picking
it on a new rule fills "> 180".

No data: each rule's state tracks its last sample and its usual gap,
smoothed so that an outage counts as at most three gaps. A core task,
alert_silence_check, runs every 60s and marks a rule no_data_since once its
series has had no sample for three usual gaps (at least 5 minutes; an hour
while the cadence is unknown). A never-sampled rule counts from when it
started watching. The mark sits beside the state, so a firing alert that
goes silent stays firing. Each silence records one event and sends one
notification (rule option notify_no_data, default on; muted in maintenance
windows). The next sample clears it with a "data resumed" event and
notification. Creating, changing, disabling or re-enabling a rule restarts
its watch.

Migration 0029 adds the columns and seeds each existing rule's last sample
and gap from its last day of data, so an upgrade does not flag every rule.

Shown on the Alerts page (a NO DATA badge with its start time), in MCP
list_alerts, list_alert_rules and get_host (state "no_data", no_data_since),
in get_overview findings (alert_no_data, or a firing alert marked silent)
and in the weekly report. The rule form has the notify option, and its
metric reference now matches what traefik records and lists host_agent.
Emails say "no data" and carry the event's note.

The metric-catalog guard also reads positional MetricBatch.add arguments.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-06 13:06:54 -04:00

99 lines
4.0 KiB
Python

"""Silence is alertable (#5062): a series' usual gap is learned from its
samples, an outage does not become its cadence, and a series counts as silent
after three usual gaps (at least five minutes; an hour while its cadence is
unknown)."""
from datetime import datetime, timedelta, timezone
from types import SimpleNamespace as NS
import pytest
from steward.core.alerts import (
NO_DATA_FLOOR_S, NO_DATA_UNKNOWN_S, _track_samples, next_interval, no_data_after, silent_since,
)
from steward.models.alerts import AlertStateEnum
NOW = datetime(2026, 10, 6, 12, 0, tzinfo=timezone.utc)
@pytest.mark.parametrize("interval,gap,want", [
(None, 60, 60), # the first gap is the cadence
(0.0, 30, 30),
(60, 60, 60), # steady
(60, 80, 65), # a late sample barely moves it
(60, 3600, 90), # an outage counts as at most three gaps
(60, -5, 45), # never a negative gap
])
def test_next_interval(interval, gap, want):
assert next_interval(interval, gap) == pytest.approx(want)
def test_a_new_cadence_is_learned_in_steps():
interval, steps = 60.0, 0
while no_data_after(interval) < 600: # samples now arrive every 10 minutes
interval, steps = next_interval(interval, 600), steps + 1
assert steps == 3
@pytest.mark.parametrize("interval,want", [
(None, NO_DATA_UNKNOWN_S), (0.0, NO_DATA_UNKNOWN_S),
(30, NO_DATA_FLOOR_S), (100, 300), (600, 1800),
])
def test_no_data_after(interval, want):
assert no_data_after(interval) == want
@pytest.mark.parametrize("last_ago,interval,watch_ago,silent_after", [
(60, 60, 9999, None), # reporting
(300, 60, 9999, None), # exactly at the limit is not yet silent
(301, 60, 9999, 300), # silent since last + 300s
(2000, 600, 9999, 1800), # slow series: three of its gaps
(None, None, 3000, None), # never sampled, watched under an hour
(None, None, 4000, 3600), # never sampled, watched over an hour
])
def test_silent_since(last_ago, interval, watch_ago, silent_after):
last = NOW - timedelta(seconds=last_ago) if last_ago is not None else None
watch = NOW - timedelta(seconds=watch_ago)
got = silent_since(last, interval, watch, NOW)
if silent_after is None:
assert got is None
else:
assert got == (last or watch) + timedelta(seconds=silent_after)
class _Session:
def __init__(self):
self.added = []
def add(self, row):
self.added.append(row)
def _state(**kw):
base = dict(state=AlertStateEnum.firing, last_sample_at=None, sample_interval_s=None,
no_data_since=None)
return NS(**{**base, **kw})
def _samples(*ago_values):
return [NS(recorded_at=NOW - timedelta(seconds=a), value=v) for a, v in ago_values]
def test_tracking_learns_the_gap_and_skips_late_samples():
st, session = _state(), _Session()
assert _track_samples(session, NS(id="r"), st, _samples((180, 1), (120, 1), (60, 1)), NOW) is None
assert (st.last_sample_at, st.sample_interval_s) == (NOW - timedelta(seconds=60), 60)
_track_samples(session, NS(id="r"), st, _samples((90, 1)), NOW) # older than the last
assert (st.last_sample_at, st.sample_interval_s) == (NOW - timedelta(seconds=60), 60)
assert session.added == []
def test_a_sample_after_silence_clears_it_and_records_the_resume():
st, session = _state(last_sample_at=NOW - timedelta(minutes=20), sample_interval_s=60,
no_data_since=NOW - timedelta(minutes=15)), _Session()
event_id, value, note = _track_samples(session, NS(id="r"), st, _samples((0, 42.0)), NOW)
assert st.no_data_since is None and st.state == AlertStateEnum.firing # still firing
assert st.sample_interval_s == 90 # the outage counted as three gaps, at most
assert value == 42.0 and note == "data resumed after 15m silent"
[event] = session.added
assert (event.id, event.from_state, event.to_state) == (event_id, "no_data", "firing")