Alerts

Alert rules

Notify yourself when things break — without spamming yourself when they don't.

Alert rules trigger when a metric crosses a threshold for a sustained window. The defaults err on the side of fewer alerts; you can tune them per project.

Built-in rules

RuleDefault trigger
Method error rate> 1% errors over 5 min, sustained 10 min
Method p95 latency> 1s for 10 min
Observer leakobserver count rises 5+ min, > 50 leaked
MongoDB COLLSCANsustained COLLSCAN over 5 min
Event-loop lag> 200ms p95 for 5 min
Uptime monitor2 consecutive failures (configurable)

Custom rules

Create a custom rule from the dashboard:

when methods('orders.create').p99 > 800ms for 10m
notify slack:#oncall

The full DSL is documented in Custom alert DSL.

Channels

Email, Slack, Discord, generic webhook, PagerDuty. Configure under Settings → Channels.