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Database (N+1 and slow query)

TL;DR. Statements-per-request counter + slow-query span events, sourced from the Spring 6.2 DB Observation. Catches N+1s in PromQL instead of in a tail-latency post-mortem.

The N+1 query bug is the most common Spring/JPA performance footgun, and it's invisible to most observability stacks because each individual statement looks fine — it's the count per request that matters.

Pulse counts statements per request. When one route accidentally fires fifty queries, you see it in a metric instead of in a tail-latency investigation.

What you get

sum by (endpoint) (rate(pulse_db_n_plus_one_suspect_total[5m])) > 0

Any non-zero result is a route that crossed the threshold (default 50 statements per request) at least once in the window. The shipped alert points straight at the endpoint.

You also get the per-request distribution itself, so you can spot drift over time:

histogram_quantile(0.95,
  sum by (endpoint, le) (rate(pulse_db_statements_per_request_bucket[5m])))

Turn it on

Nothing — automatic when Hibernate ORM is on the classpath.

To raise or lower the threshold:

pulse:
  db:
    n-plus-one-threshold: 30

What it adds

Metric / signal Meaning
pulse.db.statements_per_request Distribution summary, prepared statements per request
pulse.db.n_plus_one.suspect (tag endpoint) Counter — fires when the threshold trips
Span event pulse.db.n_plus_one.suspect Marks the offending request in the trace
WARN log (one-time per endpoint per minute) Surfaces it without scraping Prometheus

Slow queries flow through Hibernate's built-in org.hibernate.SQL_SLOW logger, automatically correlated with the trace by Pulse's structured logs layout.

When to skip it

If you already use p6spy, Datadog APM, or another query-counting layer:

pulse:
  db:
    enabled: false

Conditional gating

To suppress N+1 detection for known-chatty admin endpoints (bulk imports, batch reconciliation jobs that legitimately fire hundreds of statements) without raising the global threshold, use enabled-when:

pulse:
  db:
    enabled-when:
      path-excludes:
        - /admin/bulk-import
        - /admin/reconcile

Requests excluded by the matcher don't open the per-request statement scope at all — no pulse.db.* metrics, no warning, no trace event.

Source: io.github.arun0009.pulse.db · Status: Stable since 1.0.0