- ledgerline.transactions.total (counter: kind, status, currency) and
ledgerline.transaction.duration (histogram, seconds: kind) in gateway,
the only place that sees the final outcome, failures included. currency
is client input, so values outside the seeded set are recorded as
"other".
- ledgerline.fraud.score (histogram, buckets in 0.1 steps to 1.0) in fraud.
- ledgerline.stream.lag (observable gauge: consumer_group) in audit and
notifier, read from XINFO GROUPS through a separate sync Redis client,
because callbacks run on the scrape thread; the call is untraced so
scrapes don't create traces.
- ledgerline.db.pool.in_use (observable up-down counter: pool) in every
service with a DB engine. The SQLAlchemy instrumentation's own pool
metric names a pool by DSN, which merges the normal and starved engines.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>