metrics

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Published: Oct 21, 2013 License: BSD-2-Clause-Views Imports: 16 Imported by: 0

README

go-metrics

Go port of Coda Hale's Metrics library: https://github.com/codahale/metrics.

Documentation: http://godoc.org/github.com/rcrowley/go-metrics.

Usage

Create and update metrics:

c := metrics.NewCounter()
metrics.Register("foo", c)
c.Inc(47)

g := metrics.NewGauge()
metrics.Register("bar", g)
g.Update(47)

s := metrics.NewExpDecaySample(1028, 0.015) // or metrics.NewUniformSample(1028)
h := metrics.NewHistogram(s)
metrics.Register("baz", h)
h.Update(47)

m := metrics.NewMeter()
metrics.Register("quux", m)
m.Mark(47)

t := metrics.NewTimer()
metrics.Register("bang", t)
t.Time(func() {})
t.Update(47)

Periodically log every metric in human-readable form to standard error:

go metrics.Log(metrics.DefaultRegistry, 60e9, log.New(os.Stderr, "metrics: ", log.Lmicroseconds))

Periodically log every metric in slightly-more-parseable form to syslog:

w, _ := syslog.Dial("unixgram", "/dev/log", syslog.LOG_INFO, "metrics")
go metrics.Syslog(metrics.DefaultRegistry, 60e9, w)

Periodically emit every metric to Graphite:

addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:2003")
go metrics.Graphite(metrics.DefaultRegistry, 10e9, "metrics", addr)

Periodically emit every metric to StatHat:

import "github.com/rcrowley/go-metrics/stathat"

stathat.Stathat(metrics.DefaultRegistry, 10e9, "example@example.com")

Installation

go get github.com/rcrowley/go-metrics

StatHat support additionally requires their Go client:

go get github.com/stathat/go

Documentation

Overview

Go port of Coda Hale's Metrics library

<https://github.com/rcrowley/go-metrics>

Coda Hale's original work: <https://github.com/codahale/metrics>

Index

Constants

This section is empty.

Variables

View Source
var UseNilMetrics bool = false

UseNilMetrics is checked by the constructor functions for all of the standard metrics. If it is true, the metric returned is a stub.

This global kill-switch helps quantify the observer effect and makes for less cluttered pprof profiles.

Functions

func CaptureDebugGCStats

func CaptureDebugGCStats(r Registry, d time.Duration)

Capture new values for the Go garbage collector statistics exported in debug.GCStats. This is designed to be called as a goroutine.

func CaptureDebugGCStatsOnce

func CaptureDebugGCStatsOnce(r Registry)

Capture new values for the Go garbage collector statistics exported in debug.GCStats. This is designed to be called in a background goroutine. Giving a registry which has not been given to RegisterDebugGCStats will panic.

func CaptureRuntimeMemStats

func CaptureRuntimeMemStats(r Registry, d time.Duration)

Capture new values for the Go runtime statistics exported in runtime.MemStats. This is designed to be called as a goroutine.

func CaptureRuntimeMemStatsOnce

func CaptureRuntimeMemStatsOnce(r Registry)

Capture new values for the Go runtime statistics exported in runtime.MemStats. This is designed to be called in a background goroutine. Giving a registry which has not been given to RegisterRuntimeMemStats will panic.

func Each

func Each(f func(string, interface{}))

Call the given function for each registered metric.

func Get

func Get(name string) interface{}

Get the metric by the given name or nil if none is registered.

func Graphite

func Graphite(r Registry, d time.Duration, prefix string, addr *net.TCPAddr)

func Log

func Log(r Registry, d time.Duration, l *log.Logger)

Output each metric in the given registry periodically using the given logger.

func Register

func Register(name string, i interface{})

Register the given metric under the given name.

func RegisterDebugGCStats

func RegisterDebugGCStats(r Registry)

Register metrics for the Go garbage collector statistics exported in debug.GCStats. The metrics are named by their fully-qualified Go symbols, i.e. debug.GCStats.PauseTotal.

func RegisterRuntimeMemStats

func RegisterRuntimeMemStats(r Registry)

Register runtimeMetrics for the Go runtime statistics exported in runtime and specifically runtime.MemStats. The runtimeMetrics are named by their fully-qualified Go symbols, i.e. runtime.MemStats.Alloc.

func RunHealthchecks

func RunHealthchecks()

Run all registered healthchecks.

func Syslog

func Syslog(r Registry, d time.Duration, w *syslog.Writer)

Output each metric in the given registry to syslog periodically using the given syslogger.

func Unregister

func Unregister(name string)

Unregister the metric with the given name.

func Write

func Write(r Registry, d time.Duration, w io.Writer)

Output each metric in the given registry periodically using the given io.Writer.

Types

type Counter

type Counter interface {
	Clear()
	Count() int64
	Dec(int64)
	Inc(int64)
}

Counters hold an int64 value that can be incremented and decremented.

This is an interface so as to encourage other structs to implement the Counter API as appropriate.

func NewCounter

func NewCounter() Counter

Create a new Counter.

type EWMA

type EWMA interface {
	Rate() float64
	Tick()
	Update(int64)
}

EWMAs continuously calculate an exponentially-weighted moving average based on an outside source of clock ticks.

This is an interface so as to encourage other structs to implement the EWMA API as appropriate.

func NewEWMA

func NewEWMA(alpha float64) EWMA

Create a new EWMA with the given alpha.

func NewEWMA1

func NewEWMA1() EWMA

Create a new EWMA with alpha set for a one-minute moving average.

func NewEWMA15

func NewEWMA15() EWMA

Create a new EWMA with alpha set for a fifteen-minute moving average.

func NewEWMA5

func NewEWMA5() EWMA

Create a new EWMA with alpha set for a five-minute moving average.

type ExpDecaySample

type ExpDecaySample struct {
	// contains filtered or unexported fields
}

An exponentially-decaying sample using a forward-decaying priority reservoir. See Cormode et al's "Forward Decay: A Practical Time Decay Model for Streaming Systems".

<http://www.research.att.com/people/Cormode_Graham/library/publications/CormodeShkapenyukSrivastavaXu09.pdf>

func (*ExpDecaySample) Clear

func (s *ExpDecaySample) Clear()

Clear all samples.

func (*ExpDecaySample) Size

func (s *ExpDecaySample) Size() int

Return the size of the sample, which is at most the reservoir size.

func (*ExpDecaySample) Update

func (s *ExpDecaySample) Update(v int64)

Update the sample with a new value.

func (*ExpDecaySample) Values

func (s *ExpDecaySample) Values() []int64

Return all the values in the sample.

type Gauge

type Gauge interface {
	Update(int64)
	Value() int64
}

Gauges hold an int64 value that can be set arbitrarily.

This is an interface so as to encourage other structs to implement the Gauge API as appropriate.

func NewGauge

func NewGauge() Gauge

Create a new Gauge.

type Healthcheck

type Healthcheck interface {
	Check()
	Error() error
	Healthy()
	Unhealthy(error)
}

Healthchecks hold an os.Error value describing an arbitrary up/down status.

This is an interface so as to encourage other structs to implement the Healthcheck API as appropriate.

func NewHealthcheck

func NewHealthcheck(f func(Healthcheck)) Healthcheck

Create a new Healthcheck, which will use the given function to update its status.

type Histogram

type Histogram interface {
	Clear()
	Count() int64
	Max() int64
	Mean() float64
	Min() int64
	Percentile(float64) float64
	Percentiles([]float64) []float64
	StdDev() float64
	Update(int64)
	Variance() float64
}

Histograms calculate distribution statistics from an int64 value.

This is an interface so as to encourage other structs to implement the Histogram API as appropriate.

func NewHistogram

func NewHistogram(s Sample) Histogram

Create a new Histogram with the given Sample. The initial values compare so that the first value will be both min and max and the variance is flagged for special treatment on its first iteration.

type Meter

type Meter interface {
	Count() int64
	Mark(int64)
	Rate1() float64
	Rate5() float64
	Rate15() float64
	RateMean() float64
}

Meters count events to produce exponentially-weighted moving average rates at one-, five-, and fifteen-minutes and a mean rate.

This is an interface so as to encourage other structs to implement the Meter API as appropriate.

func NewMeter

func NewMeter() Meter

Create a new Meter. Create the communication channels and start the synchronizing goroutine.

type NilCounter

type NilCounter struct{}

No-op Counter.

func (NilCounter) Clear

func (c NilCounter) Clear()

No-op.

func (NilCounter) Count

func (c NilCounter) Count() int64

No-op.

func (NilCounter) Dec

func (c NilCounter) Dec(i int64)

No-op.

func (NilCounter) Inc

func (c NilCounter) Inc(i int64)

No-op.

type NilEWMA

type NilEWMA struct{}

No-op EWMA.

func (NilEWMA) Rate

func (a NilEWMA) Rate() float64

No-op.

func (NilEWMA) Tick

func (a NilEWMA) Tick()

No-op.

func (NilEWMA) Update

func (a NilEWMA) Update(n int64)

No-op.

type NilGauge

type NilGauge struct{}

No-op Gauge.

func (NilGauge) Update

func (g NilGauge) Update(v int64)

No-op.

func (NilGauge) Value

func (g NilGauge) Value() int64

No-op.

type NilHealthcheck

type NilHealthcheck struct{}

No-op Healthcheck.

func (NilHealthcheck) Check

func (h NilHealthcheck) Check()

No-op.

func (NilHealthcheck) Error

func (h NilHealthcheck) Error() error

No-op.

func (NilHealthcheck) Healthy

func (h NilHealthcheck) Healthy()

No-op.

func (NilHealthcheck) Unhealthy

func (h NilHealthcheck) Unhealthy(err error)

No-op.

type NilHistogram

type NilHistogram struct{}

No-op Histogram.

func (NilHistogram) Clear

func (h NilHistogram) Clear()

No-op.

func (NilHistogram) Count

func (h NilHistogram) Count() int64

No-op.

func (NilHistogram) Max

func (h NilHistogram) Max() int64

No-op.

func (NilHistogram) Mean

func (h NilHistogram) Mean() float64

No-op.

func (NilHistogram) Min

func (h NilHistogram) Min() int64

No-op.

func (NilHistogram) Percentile

func (h NilHistogram) Percentile(p float64) float64

No-op.

func (NilHistogram) Percentiles

func (h NilHistogram) Percentiles(ps []float64) []float64

No-op.

func (NilHistogram) StdDev

func (h NilHistogram) StdDev() float64

No-op.

func (NilHistogram) Update

func (h NilHistogram) Update(v int64)

No-op.

func (NilHistogram) Variance

func (h NilHistogram) Variance() float64

No-op.

type NilMeter

type NilMeter struct{}

No-op Meter.

func (NilMeter) Count

func (m NilMeter) Count() int64

No-op.

func (NilMeter) Mark

func (m NilMeter) Mark(n int64)

No-op.

func (NilMeter) Rate1

func (m NilMeter) Rate1() float64

No-op.

func (NilMeter) Rate15

func (m NilMeter) Rate15() float64

No-op.

func (NilMeter) Rate5

func (m NilMeter) Rate5() float64

No-op.

func (NilMeter) RateMean

func (m NilMeter) RateMean() float64

No-op.

type NilSample

type NilSample struct{}

No-op Sample.

func (NilSample) Clear

func (s NilSample) Clear()

No-op.

func (NilSample) Size

func (s NilSample) Size() int

No-op.

func (NilSample) Update

func (s NilSample) Update(v int64)

No-op.

func (NilSample) Values

func (s NilSample) Values() []int64

No-op.

type NilTimer

type NilTimer struct {
	// contains filtered or unexported fields
}

No-op Timer.

func (NilTimer) Count

func (t NilTimer) Count() int64

No-op.

func (NilTimer) Max

func (t NilTimer) Max() int64

No-op.

func (NilTimer) Mean

func (t NilTimer) Mean() float64

No-op.

func (NilTimer) Min

func (t NilTimer) Min() int64

No-op.

func (NilTimer) Percentile

func (t NilTimer) Percentile(p float64) float64

No-op.

func (NilTimer) Percentiles

func (t NilTimer) Percentiles(ps []float64) []float64

No-op.

func (NilTimer) Rate1

func (t NilTimer) Rate1() float64

No-op.

func (NilTimer) Rate15

func (t NilTimer) Rate15() float64

No-op.

func (NilTimer) Rate5

func (t NilTimer) Rate5() float64

No-op.

func (NilTimer) RateMean

func (t NilTimer) RateMean() float64

No-op.

func (NilTimer) StdDev

func (t NilTimer) StdDev() float64

No-op.

func (NilTimer) Time

func (t NilTimer) Time(f func())

No-op.

func (NilTimer) Update

func (t NilTimer) Update(d time.Duration)

No-op.

func (NilTimer) UpdateSince

func (t NilTimer) UpdateSince(ts time.Time)

No-op.

type Registry

type Registry interface {

	// Call the given function for each registered metric.
	Each(func(string, interface{}))

	// Get the metric by the given name or nil if none is registered.
	Get(string) interface{}

	// Register the given metric under the given name.
	Register(string, interface{})

	// Run all registered healthchecks.
	RunHealthchecks()

	// Unregister the metric with the given name.
	Unregister(string)
}

A Registry holds references to a set of metrics by name and can iterate over them, calling callback functions provided by the user.

This is an interface so as to encourage other structs to implement the Registry API as appropriate.

var DefaultRegistry Registry = NewRegistry()

func NewRegistry

func NewRegistry() Registry

Create a new registry.

type Sample

type Sample interface {
	Clear()
	Size() int
	Update(int64)
	Values() []int64
}

Samples maintain a statistically-significant selection of values from a stream.

This is an interface so as to encourage other structs to implement the Sample API as appropriate.

func NewExpDecaySample

func NewExpDecaySample(reservoirSize int, alpha float64) Sample

Create a new exponentially-decaying sample with the given reservoir size and alpha.

func NewUniformSample

func NewUniformSample(reservoirSize int) Sample

Create a new uniform sample with the given reservoir size.

type StandardCounter

type StandardCounter struct {
	// contains filtered or unexported fields
}

The standard implementation of a Counter uses the sync/atomic package to manage a single int64 value.

func (*StandardCounter) Clear

func (c *StandardCounter) Clear()

Clear the counter: set it to zero.

func (*StandardCounter) Count

func (c *StandardCounter) Count() int64

Return the current count.

func (*StandardCounter) Dec

func (c *StandardCounter) Dec(i int64)

Decrement the counter by the given amount.

func (*StandardCounter) Inc

func (c *StandardCounter) Inc(i int64)

Increment the counter by the given amount.

type StandardEWMA

type StandardEWMA struct {
	// contains filtered or unexported fields
}

The standard implementation of an EWMA tracks the number of uncounted events and processes them on each tick. It uses the sync/atomic package to manage uncounted events.

func (*StandardEWMA) Rate

func (a *StandardEWMA) Rate() float64

Return the moving average rate of events per second.

func (*StandardEWMA) Tick

func (a *StandardEWMA) Tick()

Tick the clock to update the moving average.

func (*StandardEWMA) Update

func (a *StandardEWMA) Update(n int64)

Add n uncounted events.

type StandardGauge

type StandardGauge struct {
	// contains filtered or unexported fields
}

The standard implementation of a Gauge uses the sync/atomic package to manage a single int64 value.

func (*StandardGauge) Update

func (g *StandardGauge) Update(v int64)

Update the gauge's value.

func (*StandardGauge) Value

func (g *StandardGauge) Value() int64

Return the gauge's current value.

type StandardHealthcheck

type StandardHealthcheck struct {
	// contains filtered or unexported fields
}

The standard implementation of a Healthcheck stores the status and a function to call to update the status.

func (*StandardHealthcheck) Check

func (h *StandardHealthcheck) Check()

Update the healthcheck's status.

func (*StandardHealthcheck) Error

func (h *StandardHealthcheck) Error() error

Return the healthcheck's status, which will be nil if it is healthy.

func (*StandardHealthcheck) Healthy

func (h *StandardHealthcheck) Healthy()

Mark the healthcheck as healthy.

func (*StandardHealthcheck) Unhealthy

func (h *StandardHealthcheck) Unhealthy(err error)

Mark the healthcheck as unhealthy. The error should provide details.

type StandardHistogram

type StandardHistogram struct {
	// contains filtered or unexported fields
}

The standard implementation of a Histogram uses a Sample and a goroutine to synchronize its calculations.

func (*StandardHistogram) Clear

func (h *StandardHistogram) Clear()

Clear the histogram.

func (*StandardHistogram) Count

func (h *StandardHistogram) Count() int64

Return the count of inputs since the histogram was last cleared.

func (*StandardHistogram) Max

func (h *StandardHistogram) Max() int64

Return the maximal value seen since the histogram was last cleared.

func (*StandardHistogram) Mean

func (h *StandardHistogram) Mean() float64

Return the mean of all values seen since the histogram was last cleared.

func (*StandardHistogram) Min

func (h *StandardHistogram) Min() int64

Return the minimal value seen since the histogram was last cleared.

func (*StandardHistogram) Percentile

func (h *StandardHistogram) Percentile(p float64) float64

Return an arbitrary percentile of all values seen since the histogram was last cleared.

func (*StandardHistogram) Percentiles

func (h *StandardHistogram) Percentiles(ps []float64) []float64

Return a slice of arbitrary percentiles of all values seen since the histogram was last cleared.

func (*StandardHistogram) StdDev

func (h *StandardHistogram) StdDev() float64

Return the standard deviation of all values seen since the histogram was last cleared.

func (*StandardHistogram) Update

func (h *StandardHistogram) Update(v int64)

Update the histogram with a new value.

func (*StandardHistogram) Variance

func (h *StandardHistogram) Variance() float64

Return the variance of all values seen since the histogram was last cleared.

type StandardMeter

type StandardMeter struct {
	// contains filtered or unexported fields
}

The standard implementation of a Meter uses a goroutine to synchronize its calculations and another goroutine (via time.Ticker) to produce clock ticks.

func (*StandardMeter) Count

func (m *StandardMeter) Count() int64

Return the count of events seen.

func (*StandardMeter) Mark

func (m *StandardMeter) Mark(n int64)

Mark the occurance of n events.

func (*StandardMeter) Rate1

func (m *StandardMeter) Rate1() float64

Return the meter's one-minute moving average rate of events.

func (*StandardMeter) Rate15

func (m *StandardMeter) Rate15() float64

Return the meter's fifteen-minute moving average rate of events.

func (*StandardMeter) Rate5

func (m *StandardMeter) Rate5() float64

Return the meter's five-minute moving average rate of events.

func (*StandardMeter) RateMean

func (m *StandardMeter) RateMean() float64

Return the meter's mean rate of events.

type StandardRegistry

type StandardRegistry struct {
	// contains filtered or unexported fields
}

The standard implementation of a Registry is a mutex-protected map of names to metrics.

func (*StandardRegistry) Each

func (r *StandardRegistry) Each(f func(string, interface{}))

Call the given function for each registered metric.

func (*StandardRegistry) Get

func (r *StandardRegistry) Get(name string) interface{}

Get the metric by the given name or nil if none is registered.

func (StandardRegistry) MarshalJSON

func (r StandardRegistry) MarshalJSON() ([]byte, error)

MarshalJSON returns a byte slice containing a JSON representation of all the metrics in the Registry.

func (*StandardRegistry) Register

func (r *StandardRegistry) Register(name string, i interface{})

Register the given metric under the given name.

func (*StandardRegistry) RunHealthchecks

func (r *StandardRegistry) RunHealthchecks()

Run all registered healthchecks.

func (*StandardRegistry) Unregister

func (r *StandardRegistry) Unregister(name string)

Unregister the metric with the given name.

type StandardTimer

type StandardTimer struct {
	// contains filtered or unexported fields
}

The standard implementation of a Timer uses a Histogram and Meter directly.

func (*StandardTimer) Count

func (t *StandardTimer) Count() int64

Return the count of inputs.

func (*StandardTimer) Max

func (t *StandardTimer) Max() int64

Return the maximal value seen.

func (*StandardTimer) Mean

func (t *StandardTimer) Mean() float64

Return the mean of all values seen.

func (*StandardTimer) Min

func (t *StandardTimer) Min() int64

Return the minimal value seen.

func (*StandardTimer) Percentile

func (t *StandardTimer) Percentile(p float64) float64

Return an arbitrary percentile of all values seen.

func (*StandardTimer) Percentiles

func (t *StandardTimer) Percentiles(ps []float64) []float64

Return a slice of arbitrary percentiles of all values seen.

func (*StandardTimer) Rate1

func (t *StandardTimer) Rate1() float64

Return the meter's one-minute moving average rate of events.

func (*StandardTimer) Rate15

func (t *StandardTimer) Rate15() float64

Return the meter's fifteen-minute moving average rate of events.

func (*StandardTimer) Rate5

func (t *StandardTimer) Rate5() float64

Return the meter's five-minute moving average rate of events.

func (*StandardTimer) RateMean

func (t *StandardTimer) RateMean() float64

Return the meter's mean rate of events.

func (*StandardTimer) StdDev

func (t *StandardTimer) StdDev() float64

Return the standard deviation of all values seen.

func (*StandardTimer) Time

func (t *StandardTimer) Time(f func())

Record the duration of the execution of the given function.

func (*StandardTimer) Update

func (t *StandardTimer) Update(d time.Duration)

Record the duration of an event.

func (*StandardTimer) UpdateSince

func (t *StandardTimer) UpdateSince(ts time.Time)

Record the duration of an event that started at a time and ends now.

type Timer

type Timer interface {
	Count() int64
	Max() int64
	Mean() float64
	Min() int64
	Percentile(float64) float64
	Percentiles([]float64) []float64
	Rate1() float64
	Rate5() float64
	Rate15() float64
	RateMean() float64
	StdDev() float64
	Time(func())
	Update(time.Duration)
	UpdateSince(time.Time)
}

Timers capture the duration and rate of events.

This is an interface so as to encourage other structs to implement the Timer API as appropriate.

func NewCustomTimer

func NewCustomTimer(h Histogram, m Meter) Timer

Create a new timer with the given Histogram and Meter.

func NewTimer

func NewTimer() Timer

Create a new timer with a standard histogram and meter. The histogram will use an exponentially-decaying sample with the same reservoir size and alpha as UNIX load averages.

type UniformSample

type UniformSample struct {
	// contains filtered or unexported fields
}

A uniform sample using Vitter's Algorithm R.

<http://www.cs.umd.edu/~samir/498/vitter.pdf>

func (*UniformSample) Clear

func (s *UniformSample) Clear()

Clear all samples.

func (*UniformSample) Size

func (s *UniformSample) Size() int

Return the size of the sample, which is at most the reservoir size.

func (*UniformSample) Update

func (s *UniformSample) Update(v int64)

Update the sample with a new value.

func (*UniformSample) Values

func (s *UniformSample) Values() []int64

Return all the values in the sample.

Directories

Path Synopsis
cmd
Metrics output to StatHat.
Metrics output to StatHat.

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