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>
#5012 "get_host cuts `parts` without saying so"
- The agent's sub-resources come back as mounts (fullest first),
interfaces and disk_io (busiest first) and temperatures (hottest first),
each bounded on its own with total, truncated and a `more` that names
parts_limit and query_metrics.
- Per-core CPU is a summary (count, min/avg/max, three busiest), so 38
cores no longer push every interface out of the reply.
- New argument parts_limit (default 20, max 200).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
MCP-4 of milestone 461 "MCP server: Steward as an LLM-inspectable,
LLM-operable hub". Twelve read-only viewer tools:
- get_overview: what is wrong now, ranked critical-then-oldest. Failing
monitors with their error and when the run of failures began, firing,
pending and still-breaching acknowledged alerts, TLS certificates expiring
within 14 days, agents that stopped reporting, hosts over the configured
CPU/memory/disk thresholds (Settings > Thresholds), failed Ansible runs in
the last 24h, and findings from enabled plugins through a new optional
`mcp_overview(db)` plugin hook. Each finding names the call that shows
its evidence.
- list_hosts, get_host, get_host_metrics
- list_monitors, get_monitor (HTTP header values and URL passwords are
redacted)
- list_alerts, get_alert_history, list_alert_rules, list_maintenance_windows
- query_metrics: the whole metric store, narrowed one argument at a time
(sources > resources > latest values > a series summary)
- list_audit_events
Shared shaping in steward/mcp/tools/_shape.py: UTC ISO times with age_s,
bounded lists that say when and how they were cut, series as
min/avg/max/p95/last plus a ≤60-point series, lookup by id or
case-insensitive name with a did-you-mean, and a range argument that
refuses an unknown key instead of reading it as 24h.
New core reads in steward/core/metric_series.py (sources and resources
via loose index scans, latest values via DISTINCT ON, series across the
raw/hourly-rollup seam). monitors/service.py gains monitor_states,
down_since and recent_failures; agent_overview_by_host now carries the
fullest disk and the last sample time.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>