configures the backend the metrics values are sent to.

Possible values are:

  • <empty>: do not report metrics
  • stdout: report metrics to stdout
  • graphite: report metrics to Graphite on metrics.graphite.addr
  • statsd: legacy statsd support, used in v1.5.5 and lower - removed in v1.6
  • statsd_raw: report metrics to StatsD on metrics.statsd.addr - this was intentionally renamed because anyone upgrading to 1.6 will need to revisit their configuration anyway due to rewrite of this backend. It was quite broken before, the counters never reset, it did not follow the spec so the info was likely wrong or people using this were doing some workarounds they’ll need to remove anyway.
  • circonus: report metrics to Circonus (
  • prometheus: use prometheus metrics. ( Must be used in conjuction with a prometheus listener in proxy.addr
  • dogstatsd: use with datadog dogstatsd (

The default is =

Multiple metrics targets can be defined separated by comma.