Timer metric

JSON object metric combining a summary with other statistics.

Timer values have the following fields:

{
  "count": (number) events recorded for this metric,
  "total": (number) sum of the durations of events recorded for this metric,
  "mean_rate": (number) average rate,
  "m1_rate": (number) one-minute average rate,
  "m5_rate": (number) five-minute average rate,
  "m15_rate": (number) fifteen-minute average rate,
  "mean": (number) total/count, or 0 if count is 0,
  "min": (number) minimum duration recorded,
  "max": (number) maximum duration recorded,
  "stddev": (number) standard deviation of recorded durations,
  "p50": (number) 50% at or below this value,
  "p75": (number) 75% at or below this value,
  "p95": (number) 95% at or below this value,
  "p98": (number) 98% at or below this value,
  "p99": (number) 99% at or below this value,
  "p999": (number) 99.9% at or below this value,
  "p9999": (number) 99.99% at or below this value,
  "p99999": (number) 99.999% at or below this value
}