# Instrumentation !!! info "Added in 19.1" Gunicorn exposes optional instrumentation for the arbiter and workers using the statsD protocol over UDP. The `gunicorn.instrument.statsd` module turns Gunicorn into a statsD client. UDP keeps Gunicorn isolated from slow statsD consumers, so metrics collection does not impact request handling. Tell Gunicorn where the statsD server is located: ```bash gunicorn --statsd-host=localhost:8125 --statsd-prefix=service.app ... ``` The `Statsd` logger subclasses `gunicorn.glogging.Logger` and tracks: - `gunicorn.requests` — request rate per second - `gunicorn.request.duration` — request duration histogram (milliseconds.md) - `gunicorn.workers` — number of workers managed by the arbiter (gauge.md) - `gunicorn.log.critical` — rate of critical log messages - `gunicorn.log.error` — rate of error log messages - `gunicorn.log.warning` — rate of warning log messages - `gunicorn.log.exception` — rate of exceptional log messages See the [`statsd_host`](reference/settings.md#statsd_host) setting for additional options. [statsD](https://github.com/etsy/statsd)