statsd

Documentation

Overview

Package statsd implements a statsd backend for package metrics.

The current implementation ignores fields. In the future, it would be good to have an implementation that accepted a set of predeclared field names at construction time, and used field values to produce delimiter-separated bucket (key) names. That is,

c := NewFieldedCounter(..., "path", "status")
c.Add(1) // "myprefix.unknown.unknown:1|c\n"
c2 := c.With("path", "foo").With("status": "200")
c2.Add(1) // "myprefix.foo.200:1|c\n"

Index

• func NewCallbackGauge(w io.Writer, key string, reportInterval, scrapeInterval time.Duration, ...)
• func NewCounter(w io.Writer, key string, reportInterval time.Duration) metrics.Counter
• func NewGauge(w io.Writer, key string, reportInterval time.Duration) metrics.Gauge
• func NewHistogram(w io.Writer, key string, reportInterval time.Duration) metrics.Histogram

Functions

func NewCallbackGauge

func NewCallbackGauge(w io.Writer, key string, reportInterval, scrapeInterval time.Duration, callback func() float64)

NewCallbackGauge emits values in the statsd protocol to the passed writer. It collects values every scrape interval from the callback. Values are buffered for the report interval or until the buffer exceeds a max packet size, whichever comes first. The report and scrape intervals may be the same. The callback determines the value, and fields are ignored, so NewCallbackGauge returns nothing.

func NewCounter

func NewCounter(w io.Writer, key string, reportInterval time.Duration) metrics.Counter

NewCounter returns a Counter that emits observations in the statsd protocol to the passed writer. Observations are buffered for the report interval or until the buffer exceeds a max packet size, whichever comes first. Fields are ignored.

TODO: support for sampling.

func NewGauge

func NewGauge(w io.Writer, key string, reportInterval time.Duration) metrics.Gauge

NewGauge returns a Gauge that emits values in the statsd protocol to the passed writer. Values are buffered for the report interval or until the buffer exceeds a max packet size, whichever comes first. Fields are ignored.

TODO: support for sampling.

func NewHistogram

func NewHistogram(w io.Writer, key string, reportInterval time.Duration) metrics.Histogram

NewHistogram returns a Histogram that emits observations in the statsd protocol to the passed writer. Observations are buffered for the reporting interval or until the buffer exceeds a max packet size, whichever comes first. Fields are ignored.

NewHistogram is mapped to a statsd Timing, so observations should represent milliseconds. If you observe in units of nanoseconds, you can make the translation with a ScaledHistogram:

NewScaledHistogram(statsdHistogram, time.Millisecond)

You can also enforce the constraint in a typesafe way with a millisecond TimeHistogram:

NewTimeHistogram(statsdHistogram, time.Millisecond)

TODO: support for sampling.