Recovery from bad merge of task/observer-poison-quarantine (c255a02)
which carried false deletes from a stale branch base. Re-applies only
the genuine observer changes on top of correct master state.
When an event file fails to parse (malformed JSON, truncated, corrupted),
the observer previously kept retrying on every cycle while the node's
checkpoint stayed pinned — all subsequent good events for that node lost.
Now: first parse failure -> atomic os.replace to STATE_DIR/observer_failed_events/<node>/
with collision handling. Checkpoint advances, downstream events flow.
Move failures are logged but don't crash the loop.
Complementary to the atomic_write_json fix on state files; this addresses
the same race-pattern on event files instead.
Regression test asserts: bad event quarantined to failed_events dir,
removed from hot path, subsequent good event processed (node online),
checkpoint moves to good event.
Two root causes for stale "active" incidents on the dashboard:
1. TypeError bug in _prune_stale_world: last_occurrence / resolved_at
can be an ISO-8601 string (stability-agent via events.py) or a Unix
int (node-agent). The previous session's auto-resolve did plain
`time.time() - last_occ` which raises TypeError for strings,
silently preventing _save_world() from being called and leaving
incidents perpetually "active" on disk.
Fix: add _parse_ts(ts) -> float that handles int, float, and
ISO-8601 strings uniformly. All timestamp arithmetic now goes through
it; returns 0.0 on None / garbage to keep comparisons safe.
2. Orphaned active incidents: _resolve_incident clears service["incident_id"]
and marks the incident "resolved" in memory, but if incidents.json was
truncated mid-write (pre-atomic-write era), the observer loaded it at
next startup with status="active" and no service entry pointing to it.
No code ever touched these orphans again.
Fix: _prune_stale_world now runs two cleanup passes each cycle:
- Case 1 (healthy-linked): service.status=="healthy" AND incident_id
still set → resolve immediately (service cannot have active incident)
- Case 2 (orphaned): active incident with no service link AND
last_occurrence > 5 min ago → resolve (5-min guard for creation race)
Both cases are wrapped in try/except so a bug here never crashes the
observer loop or blocks _save_world.
Also fixes the 7-day stale-incident prune to use _parse_ts so
ISO-string resolved_at values are handled correctly.
3. Operator UI: current_incidents() now filters to status=="active" only.
Resolved incidents were previously included in the /incidents endpoint,
making the dashboard show a wall of historical records as if active.
Nocturnal job investigation: _cleanup_control_plane_fs in node-agent runs
every 60s on VPS (not midnight-specific); it reads observer_checkpoint.json
(now written atomically) and deletes old event files. No non-atomic writes
found. Midnight clustering was likely external (logrotate / OS flush);
the supervisor's resilient loader already handles such transient issues.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Oskar Kapala