# LedgerlineHighErrorRatio

**Fires when:** a service's 5xx ratio is above 5% for 5 minutes, with more than
0.05 requests/s (so it is not one failed request on an idle service).
**Severity:** warning · **Team:** payments

## What it means

A meaningful share of the requests this service serves are failing with a server
error. 4xx responses (for example a 404) are deliberately not counted.

## First five minutes

1. **Look at the `RED: <service>` dashboard** (linked in the alert). Is the error
   ratio still elevated, or already back to normal? Did the request rate or the
   latency change at the same time?
2. **Find a failing request.** In Tempo, search for the service with an error
   status, or in Loki: `{service_name="<service>"} | json | level="ERROR"`.
3. **Follow one trace.** The `trace_id` in the log line opens the whole request
   across services. Look for the first span in the trace with an error status.
4. **Is it only this service?** The System overview's service graph shows whether
   its callers or callees are failing as well.

## Escalate when

The ratio is still rising after ten minutes, or the failing requests are on the
critical path (transactions), not a side route.