Observability

Sierpe is built on the principle that silent data loss is the worst failure mode. Everything it cannot index is counted, exposed and alertable.

Metrics

/metrics exposes Prometheus metrics from a private registry. The full catalogue — and which ones deserve alerts — is in docs/METRICS.md. The headline signals:

• sierpe_tip_lag_seconds — age of the last committed ledger against wall clock. Sustained growth means falling behind.
• sierpe_open_gaps — unresolved coverage gaps. Any nonzero value is declared, unserved history.
• Suppression counters — sierpe_suppressed_txs_total, _events_, _transfers_, _trustlines_. Anything Sierpe could not read is counted, never silently dropped. Alert if nonzero: that is counted data loss.
• sierpe_archive_equivalence_failures_total — the archive replay did not match the RPC byte-for-byte, so healing is disabled. Alert if nonzero (why).
• Progress signals — sierpe_ledgers_ingested_total, sierpe_backfill_pending, sierpe_gaps_healed_total, sierpe_healed_ledgers_total.

Grafana

A ready-made dashboard ships in the repository at deploy/grafana/sierpe-dashboard.json — eight panels covering the signals above.

Status page

A Gatus configuration is provided at deploy/gatus/config.yaml, including a check that turns the status page red when open gaps exist — your users see data honesty, not just uptime.

Integrity guarantees worth knowing

• The ingestion loop verifies PreviousLedgerHash continuity on every ledger, including the first one after a restart.
• Cursor and data commit in the same transaction — a crash can never leave them disagreeing.
• On testnet resets, divergence is detected and the process stops loudly with zero writes rather than mixing two histories.