The dashboard's host widgets took 18-60 s. Every "latest reading" query
(hosts overview, host-agent fleet, host page, vitals, SNMP, MCP get_host)
searched plugin_metrics for the newest row per metric. Postgres has no skip
scan, so each one read every raw sample in the 7-day window.
- plugin_metric_latest: one row per (source, resource, metric).
record_metrics upserts it in the same transaction, moving forward only and
in sorted key order. Migration 0030 seeds it by stepping the existing index.
- Retention drops a latest row once its sample leaves the raw window, so a
resource that stopped reporting disappears when its history does, as before.
Renames carry it along.
- A quiet host keeps its last values, marked stale. A time-bounded query
would have shown it as missing.
- Vitals sparklines span the 6 h they claim, averaged in SQL to ~120 points,
instead of fetching 6 h raw and drawing the last 120 samples.
- Dashboard and share-view cells: "Loading…" until the first answer; a 20 s
deadline per fetch; "Couldn't load (why)" with Retry now and an automatic
retry for cells that don't poll; "as of HH:MM" in the header, and
"couldn't refresh · as of" when a refresh fails over shown data.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
plugin_metrics grows by (sources × resources × ~30s cadence); keeping 90d of raw
is a large table. Add a raw→hourly rollup (mirroring the Docker plugin) so only a
short raw window is kept at full resolution, with hourly averages archived longer.
- PluginMetricHourly model + core migration 0024 (plugin_metrics_hourly: avg/max/
count per source/resource/metric/hour, unique bucket constraint + lookup index).
- steward/core/metrics_retention.rollup_plugin_metrics: date_trunc('hour') agg of
raw older than the hour-aligned raw window, idempotent pg upsert into hourly,
delete the rolled raw, prune hourly beyond the rollup window.
- cleanup.py: plugin_metrics is no longer blanket-deleted at data.retention_days;
_run_metrics_retention drives the rollup with windows read live from settings.
- Settings: metrics.retention.raw_days (7) + rollup_days (90), tunable on the
Thresholds & Retention page (new "Host metrics retention" card).
- Chart read: _history_for_host merges the hourly rollup (older part of the range)
with raw date_bin (recent part, capped ≤1h), so 30d charts keep working —
recent at full resolution, older at hourly. Route passes raw_days from settings.
- Tests: unit (cutoff helpers) + integration (rollup aggregates/prunes; history
merges hourly + raw) against Postgres.
Speed was already handled by the indexes + SQL aggregation; this is the storage
lever (raw window ~10x smaller).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Jg27rgypiW2efULXJDtMC
The previous commit's integration test failed at collection-time import:
importing plugins.host_agent.routes (which imports the host_agent ORM models at
top level) double-registers host_agent_registrations against the app-loaded
plugin's metadata ("Table already defined").
Move the two pure read helpers (_latest_metrics_for_host, _history_for_host)
plus SOURCE_MODULE / HISTORY_METRICS into plugins/host_agent/metrics_query.py,
which imports only the core PluginMetric model — no plugin models. routes.py
imports them back. The integration test now imports from metrics_query and no
longer trips the loader's registration guard. No behavior change.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Jg27rgypiW2efULXJDtMC