A failed restore-test was a [WARN] line in the ingest handler and nothing else —
no event, no notification, no gauge. True for the LOCAL tier that was already
being tested, so the loudest DR signal this system produces was inaudible.
Rotating tiers without this would only mean two tiers can fail silently
instead of one.
Two signals, deliberately NOT merged:
restore_test_failed (error) — a run completed and did NOT pass
restore_test_stale (warning) — a tier not PROVEN within its interval
Merging them collapses 'your DR is broken' into 'your DR is unverified', and
the second is the one that quietly becomes the first. The staleness wording
says 'unverified, not known-broken' and a test asserts that phrasing.
Anchored per R-81, not re-derived: a never-proven tier on a newborn box is
UNKNOWN, not FAILED, until the window elapses. This family has made the
opposite mistake three times; this monitor was written straight after the third,
so it copies R-81's structure rather than inventing a fourth shape.
restoreProvenStaleAfter = 7d is derived: oldest-first over two tiers at a 24h
cadence proves each ~every 2 days, so 7d tolerates ~3 missed opportunities and
sits inside the 2-week offsite retention.
Per-tier proof comes from the hub's retained host-report window — the agent
reports only its latest run, so the latest report alone cannot answer 'when was
the OTHER tier last proven?'. Reused R-81's mechanism instead of a wire change.
Both types registered in allowedEventTypes (R-77's inert-seam lesson) and
operator-tier only — no customerMessages entry.
FIXED a time bomb I introduced in Slice C: the restart-blind-window test
hard-coded 2026-07-18T18:31:06Z while comparing against the real clock. Harmless
under one 26h threshold; once the offsite tier got an 8-day limit it passed all
day and began failing at 18:31 UTC, exactly 8 days later. Now relative.
Red-proofs B and D observed. Full suite green (17 packages, rc=0).
R-81 merged every backup signal into one 'newest' against a single 26h limit.
backupStaleAfter's own comment recorded why that stops being right under a
weekly offsite tier. Each tier is now judged against its own threshold;
R-81's structure (three verdicts, anchored absence, distinct reasons) and its
boundary test are preserved intact.
- offsiteBackupStaleAfter = 8d (7d cadence + headroom); backupStaleAfter keeps
26h and now names the HOST tier only
- splitTiers / assessTier / newestBackupEvidenceByTier
Slice-A.4 rule implemented: a PBS-targeted vzdump appears in BOTH arrays, so
classification is by TARGET TYPE (target_id -> storage_targets[].name -> type),
never by array membership — otherwise a PBS backup makes a stale host tier look
fresh. storage_targets is used rather than pbs_dr.storage_id because the latter
is null on a box with a PBS storage but no DR descriptor.
A tier is only judged when the box HAS it, else every box without an offsite
tier would alarm once the anchor elapsed — R-81's mistake one level down. With
neither tier identifiable (old agent) the pre-Slice-C path runs unchanged.
Intended behaviour change: a 30h offsite snapshot no longer alarms. Three
fixtures asserted the merged threshold; each still asserts an alarm at the
correct limit. No assertion was weakened.
RECORDED LIMITATION: the hub infers 'PBS => weekly' from storage type.
defaultBackupTarget is felhom-pbs, so a box that never sets local_backup_target
would run PBS as its DAILY tier and be judged against 8 days — 7 days of
blindness. No box is in that shape today; the real fix is the agent reporting
per-tier cadences. Own task.
Red-proof observed. Replayed live: demo-felhom OK, demo-hp UNKNOWN (defers
correctly), drill-r50 MISSED (true positive). No customer email would be sent.
Third instance of one class (hub v0.12.0, v0.73.0, this), fixed as a class.
On 2026-07-26 03:00 UTC expected_backup_missed fired on demo-felhom, demo-hp
and drill-r50 at once; the demo-felhom one reached the CUSTOMER channel
claiming "newest backup is 176h0m0s old". Nothing was wrong — three vzdump
archives were on disk. Cause: the agent backup store is in-memory, so the
R-50 fleet restart emptied `backups` until the next run, and the hub read
empty as "no backup exists".
- assessBackupFreshness returns OK/UNKNOWN/MISSED instead of `missed bool`;
absence is UNKNOWN until it outlives an anchored window. Still pure.
- store.GetHostReportsSince + monitor.newestBackupEvidence read the hubs own
retained history (bounded 7-day lookback, early-exit on fresh evidence) —
"when did I last SEE evidence of a backup?" The anchor was free: the hub
already retains 90 days. No agent change, no new persisted state.
- store.GetFirstHostReportAt anchors absence at first contact, reusing the
existing 26h threshold as the grace (no new knob, the v0.73.0 shape).
- Deferrals logged + counted; reason strings kept distinct.
- backupStaleAfter untouched; landmine recorded (a weekly PBS snapshot would
alarm six days in seven) and owned by R-82.
Tests 493->508. Red-proofs A/B/C observed and restored; A reproduces the live
message verbatim. Replayed the real 03:00 reports (600/417/77 rows): all
three now silent.
Source: documentation/audits/DIAG-backup-missed-2026-07-26.md
Claude Code