metrics

package module
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 Go to latest Published: Jan 4, 2014 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.

Be careful (but much less so) with this because debug.ReadGCStats calls the C function runtime·lock(runtime·mheap) which, while not a stop-the-world operation, isn't something you want to be doing all the time.

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.

Be very careful with this because runtime.ReadMemStats calls the C functions runtime·semacquire(&runtime·worldsema) and runtime·stoptheworld() and that last one does what it says on the tin.

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 GetOrRegister 

func GetOrRegister(name string, i interface{}) interface{}

Gets an existing metric or creates and registers a new one. Threadsafe alternative to calling Get and Register on failure.

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.

func WriteOnce 

func WriteOnce(r Registry, w 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 GetOrRegisterCounter 

func GetOrRegisterCounter(name string, r Registry) Counter

Get an existing or create and register a new Counter.

func NewCounter 

func NewCounter() Counter

Create a new Counter.

func NewRegisteredCounter 

func NewRegisteredCounter(name string, r Registry) Counter

Create and register 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://dimacs.rutgers.edu/~graham/pubs/papers/fwddecay.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 GetOrRegisterGauge 

func GetOrRegisterGauge(name string, r Registry) Gauge

Get an existing or create and register a new Gauge.

func NewGauge 

func NewGauge() Gauge

Create a new Gauge.

func NewRegisteredGauge 

func NewRegisteredGauge(name string, r Registry) Gauge

Create and register 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

	Snapshot() *Snapshot
}

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 GetOrRegisterHistogram 

func GetOrRegisterHistogram(name string, r Registry, s Sample) Histogram

Get an existing or create and register a new Histogram.

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.

func NewRegisteredHistogram 

func NewRegisteredHistogram(name string, r Registry, s Sample) Histogram

Create and register a new Histogram.

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 GetOrRegisterMeter 

func GetOrRegisterMeter(name string, r Registry) Meter

Get an existing or create and register a new Meter.

func NewMeter 

func NewMeter() Meter

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

func NewRegisteredMeter 

func NewRegisteredMeter(name string, r Registry) Meter

Create and register a new Meter.

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) Snapshot 

func (h NilHistogram) Snapshot() *Snapshot

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{}

	// Gets an existing metric or creates and registers a new one.
	GetOrRegister(string, interface{}) 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 Snapshot 

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

func NewSnapshot 

func NewSnapshot(sample Sample) *Snapshot

func (*Snapshot) Count 

func (snapshot *Snapshot) Count() int64

func (*Snapshot) Max 

func (snapshot *Snapshot) Max() int64

func (*Snapshot) Mean 

func (snapshot *Snapshot) Mean() float64

func (*Snapshot) Min 

func (snapshot *Snapshot) Min() int64

func (*Snapshot) Percentile 

func (snapshot *Snapshot) Percentile(quantile float64) float64

func (*Snapshot) SortedValues 

func (snapshot *Snapshot) SortedValues() []int64

func (*Snapshot) StdDev 

func (snapshot *Snapshot) StdDev() float64

func (*Snapshot) Sum 

func (snapshot *Snapshot) Sum() (sum int64)

func (*Snapshot) Variance 

func (snapshot *Snapshot) Variance() float64

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) Snapshot 

func (h *StandardHistogram) Snapshot() *Snapshot

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) GetOrRegister 

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

Gets an existing metric or creates and registers a new one. Threadsafe alternative to calling Get and Register on failure.

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 GetOrRegisterTimer 

func GetOrRegisterTimer(name string, r Registry) Timer

Get an existing or create and register a new Timer.

func NewCustomTimer 

func NewCustomTimer(h Histogram, m Meter) Timer

Create a new timer with the given Histogram and Meter.

func NewRegisteredTimer 

func NewRegisteredTimer(name string, r Registry) Timer

Create and register a new Timer.

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.

Source Files

View all Source files

Directories

Path Synopsis
cmd
metrics-bench
metrics-example
never-read
Metrics output to StatHat.
 Metrics output to StatHat.

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