metrics

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 Go to latest Published: Jun 12, 2019 License: GPL-3.0, BSD-2-Clause-Views Imports: 20 Imported by: 12

README

go-metrics

travis build status

Go port of Coda Hale's Metrics library: https://github.com/dropwizard/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)

r := NewRegistry()
g := metrics.NewRegisteredFunctionalGauge("cache-evictions", r, func() int64 { return cache.getEvictionsCount() })

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)

Register() is not threadsafe. For threadsafe metric registration use GetOrRegister:

t := metrics.GetOrRegisterTimer("account.create.latency", nil)
t.Time(func() {})
t.Update(47)

NOTE: Be sure to unregister short-lived meters and timers otherwise they will leak memory:

// Will call Stop() on the Meter to allow for garbage collection
metrics.Unregister("quux")
// Or similarly for a Timer that embeds a Meter
metrics.Unregister("bang")

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

go metrics.Log(metrics.DefaultRegistry, 5 * time.Second, 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 using the Graphite client:


import "github.com/cyberdelia/go-metrics-graphite"

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

Periodically emit every metric into InfluxDB:

NOTE: this has been pulled out of the library due to constant fluctuations in the InfluxDB API. In fact, all client libraries are on their way out. see issues #121 and #124 for progress and details.

import "github.com/vrischmann/go-metrics-influxdb"

go influxdb.InfluxDB(metrics.DefaultRegistry,
  10e9, 
  "127.0.0.1:8086", 
  "database-name", 
  "username", 
  "password"
)

Periodically upload every metric to Librato using the Librato client:

Note: the client included with this repository under the librato package has been deprecated and moved to the repository linked above.

import "github.com/mihasya/go-metrics-librato"

go librato.Librato(metrics.DefaultRegistry,
    10e9,                  // interval
    "example@example.com", // account owner email address
    "token",               // Librato API token
    "hostname",            // source
    []float64{0.95},       // percentiles to send
    time.Millisecond,      // time unit
)

Periodically emit every metric to StatHat:

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

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

Maintain all metrics along with expvars at /debug/metrics:

This uses the same mechanism as the official expvar but exposed under /debug/metrics, which shows a json representation of all your usual expvars as well as all your go-metrics.

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

exp.Exp(metrics.DefaultRegistry)

Installation

go get github.com/rcrowley/go-metrics

StatHat support additionally requires their Go client:

go get github.com/stathat/go

Publishing Metrics

Clients are available for the following destinations:

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>

Example 
c := NewCounter()
Register("money", c)
c.Inc(17)

// Threadsafe registration
t := GetOrRegisterTimer("db.get.latency", nil)
t.Time(func() { time.Sleep(10 * time.Millisecond) })
t.Update(1)

fmt.Println(c.Count())
fmt.Println(t.Min())

Output:

17
1

Index

Examples

Constants

View Source 
const InitialResettingTimerSliceCap = 10

Initial slice capacity for the values stored in chain ResettingTimer

Variables

View Source 
var (
	MetricsEnabled       = false
	InfluxDBExportEnable = false
)

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

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

View Source 
var (
	CodexecRegistry       = NewPrefixedChildRegistry(DefaultRegistry, "/codexec")
	BranchRegistry        = NewPrefixedChildRegistry(CodexecRegistry, "/branch")
	TimeConsumingRegistry = NewPrefixedChildRegistry(CodexecRegistry, "/timeconsuming")
)

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 chain 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 chain background goroutine. Giving chain 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 chain 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 chain 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 chain background goroutine. Giving chain 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 CollectProcessMetrics 

func CollectProcessMetrics(refresh time.Duration)

CollectProcessMetrics periodically collects various metrics about the running process.

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 chain new one. Threadsafe alternative to calling Get and Register on failure.

func InitMetrics 

func InitMetrics(metricFlag, influxDBFlag bool)

func Log 

func Log(r Registry, freq time.Duration, l Logger)

func LogScaled 

func LogScaled(r Registry, freq time.Duration, scale time.Duration, l Logger)

Output each metric in the given registry periodically using the given logger. Print timings in `scale` units (eg time.Millisecond) rather than nanos.

func MustRegister 

func MustRegister(name string, i interface{})

Register the given metric under the given name. Panics if chain metric by the given name is already registered.

func ReadDiskStats 

func ReadDiskStats(stats *DiskStats) error

ReadDiskStats retrieves the disk IO stats belonging to the current process.

func RefreshCpuStats 

func RefreshCpuStats(refresh time.Duration, prevProcessCPUTime float64, prevSystemCPUUsage gosigar.Cpu) (float64, gosigar.Cpu)

func Register 

func Register(name string, i interface{}) error

Register the given metric under the given name. Returns chain DuplicateMetric if chain metric by the given name is already registered.

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 SampleMax 

func SampleMax(values []int64) int64

SampleMax returns the maximum value of the slice of int64.

func SampleMean 

func SampleMean(values []int64) float64

SampleMean returns the mean value of the slice of int64.

func SampleMin 

func SampleMin(values []int64) int64

SampleMin returns the minimum value of the slice of int64.

func SamplePercentile 

func SamplePercentile(values int64Slice, p float64) float64

SamplePercentiles returns an arbitrary percentile of the slice of int64.

func SamplePercentiles 

func SamplePercentiles(values int64Slice, ps []float64) []float64

SamplePercentiles returns chain slice of arbitrary percentiles of the slice of int64.

func SampleStdDev 

func SampleStdDev(values []int64) float64

SampleStdDev returns the standard deviation of the slice of int64.

func SampleSum 

func SampleSum(values []int64) int64

SampleSum returns the sum of the slice of int64.

func SampleVariance 

func SampleVariance(values []int64) float64

SampleVariance returns the variance of the slice of int64.

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 TimeConsuming 

func TimeConsuming(names []string, sinceTime time.Time)

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)

Write sorts writes each metric in the given registry periodically to the given io.Writer.

func WriteOnce 

func WriteOnce(r Registry, w io.Writer)

WriteOnce sorts and writes metrics in the given registry to the given io.Writer.

Types

type Config 

type Config struct {
	IsEnable         bool
	IsInfluxDBEnable bool
	InfluxDBInfo     *InfluxDBConfig
}

type Counter 

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

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

func GetOrRegisterCounter 

func GetOrRegisterCounter(name string, r Registry) Counter

GetOrRegisterCounter returns an existing Counter or constructs and registers chain new StandardCounter.

func GetOrRegisterCounterForced 

func GetOrRegisterCounterForced(name string, r Registry) Counter

GetOrRegisterCounterForced returns an existing Counter or constructs and registers chain new Counter no matter the global switch is enabled or not. Be sure to unregister the counter from the registry once it is of no use to allow for garbage collection.

func NewCounter 

func NewCounter() Counter

NewCounter constructs chain new StandardCounter.

func NewCounterForced 

func NewCounterForced() Counter

NewCounterForced constructs chain new StandardCounter and returns it no matter if the global switch is enabled or not.

func NewRegisteredCounter 

func NewRegisteredCounter(name string, r Registry) Counter

NewRegisteredCounter constructs and registers chain new StandardCounter.

func NewRegisteredCounterForced 

func NewRegisteredCounterForced(name string, r Registry) Counter

NewRegisteredCounterForced constructs and registers chain new StandardCounter and launches chain goroutine no matter the global switch is enabled or not. Be sure to unregister the counter from the registry once it is of no use to allow for garbage collection.

type CounterSnapshot 

type CounterSnapshot int64

CounterSnapshot is chain read-only copy of another Counter.

func (CounterSnapshot) Clear 

func (CounterSnapshot) Clear()

Clear panics.

func (CounterSnapshot) Count 

func (c CounterSnapshot) Count() int64

Count returns the count at the time the snapshot was taken.

func (CounterSnapshot) Dec 

func (CounterSnapshot) Dec(int64)

Dec panics.

func (CounterSnapshot) Inc 

func (CounterSnapshot) Inc(int64)

Inc panics.

func (CounterSnapshot) Snapshot 

func (c CounterSnapshot) Snapshot() Counter

Snapshot returns the snapshot.

type DiskStats 

type DiskStats struct {
	ReadCount  int64 // Number of read operations executed
	ReadBytes  int64 // Total number of bytes read
	WriteCount int64 // Number of write operations executed
	WriteBytes int64 // Total number of byte written
}

DiskStats is the per process disk io stats.

type DuplicateMetric 

type DuplicateMetric string

DuplicateMetric is the error returned by Registry.Register when chain metric already exists. If you mean to Register that metric you must first Unregister the existing metric.

func (DuplicateMetric) Error 

func (err DuplicateMetric) Error() string

type EWMA 

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

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

func NewEWMA 

func NewEWMA(alpha float64) EWMA

NewEWMA constructs chain new EWMA with the given alpha.

func NewEWMA1 

func NewEWMA1() EWMA

NewEWMA1 constructs chain new EWMA for chain one-minute moving average.

func NewEWMA15 

func NewEWMA15() EWMA

NewEWMA15 constructs chain new EWMA for chain fifteen-minute moving average.

func NewEWMA5 

func NewEWMA5() EWMA

NewEWMA5 constructs chain new EWMA for chain five-minute moving average.

type EWMASnapshot 

type EWMASnapshot float64

EWMASnapshot is chain read-only copy of another EWMA.

func (EWMASnapshot) Rate 

func (a EWMASnapshot) Rate() float64

Rate returns the rate of events per second at the time the snapshot was taken.

func (EWMASnapshot) Snapshot 

func (a EWMASnapshot) Snapshot() EWMA

Snapshot returns the snapshot.

func (EWMASnapshot) Tick 

func (EWMASnapshot) Tick()

Tick panics.

func (EWMASnapshot) Update 

func (EWMASnapshot) Update(int64)

Update panics.

type ExpDecaySample 

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

ExpDecaySample is an exponentially-decaying sample using chain 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 clears all samples.

func (*ExpDecaySample) Count 

func (s *ExpDecaySample) Count() int64

Count returns the number of samples recorded, which may exceed the reservoir size.

func (*ExpDecaySample) Max 

func (s *ExpDecaySample) Max() int64

Max returns the maximum value in the sample, which may not be the maximum value ever to be part of the sample.

func (*ExpDecaySample) Mean 

func (s *ExpDecaySample) Mean() float64

Mean returns the mean of the values in the sample.

func (*ExpDecaySample) Min 

func (s *ExpDecaySample) Min() int64

Min returns the minimum value in the sample, which may not be the minimum value ever to be part of the sample.

func (*ExpDecaySample) Percentile 

func (s *ExpDecaySample) Percentile(p float64) float64

Percentile returns an arbitrary percentile of values in the sample.

func (*ExpDecaySample) Percentiles 

func (s *ExpDecaySample) Percentiles(ps []float64) []float64

Percentiles returns chain slice of arbitrary percentiles of values in the sample.

func (*ExpDecaySample) Size 

func (s *ExpDecaySample) Size() int

Size returns the size of the sample, which is at most the reservoir size.

func (*ExpDecaySample) Snapshot 

func (s *ExpDecaySample) Snapshot() Sample

Snapshot returns chain read-only copy of the sample.

func (*ExpDecaySample) StdDev 

func (s *ExpDecaySample) StdDev() float64

StdDev returns the standard deviation of the values in the sample.

func (*ExpDecaySample) Sum 

func (s *ExpDecaySample) Sum() int64

Sum returns the sum of the values in the sample.

func (*ExpDecaySample) Update 

func (s *ExpDecaySample) Update(v int64)

Update samples chain new value.

func (*ExpDecaySample) Values 

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

Values returns chain copy of the values in the sample.

func (*ExpDecaySample) Variance 

func (s *ExpDecaySample) Variance() float64

Variance returns the variance of the values in the sample.

type FunctionalGauge 

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

FunctionalGauge returns value from given function

func (FunctionalGauge) Snapshot 

func (g FunctionalGauge) Snapshot() Gauge

Snapshot returns the snapshot.

func (FunctionalGauge) Update 

func (FunctionalGauge) Update(int64)

Update panics.

func (FunctionalGauge) Value 

func (g FunctionalGauge) Value() int64

Value returns the gauge's current value.

type FunctionalGaugeFloat64 

type FunctionalGaugeFloat64 struct {
	// contains filtered or unexported fields
}

FunctionalGaugeFloat64 returns value from given function

func (FunctionalGaugeFloat64) Snapshot 

func (g FunctionalGaugeFloat64) Snapshot() GaugeFloat64

Snapshot returns the snapshot.

func (FunctionalGaugeFloat64) Update 

func (FunctionalGaugeFloat64) Update(float64)

Update panics.

func (FunctionalGaugeFloat64) Value 

func (g FunctionalGaugeFloat64) Value() float64

Value returns the gauge's current value.

type Gauge 

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

Gauges hold an int64 value that can be set arbitrarily.

func GetOrRegisterGauge 

func GetOrRegisterGauge(name string, r Registry) Gauge

GetOrRegisterGauge returns an existing Gauge or constructs and registers chain new StandardGauge.

Example 
m := "server.bytes_sent"
g := GetOrRegisterGauge(m, nil)
g.Update(47)
fmt.Println(g.Value()) 

Output:

47

func NewFunctionalGauge 

func NewFunctionalGauge(f func() int64) Gauge

NewFunctionalGauge constructs chain new FunctionalGauge.

func NewGauge 

func NewGauge() Gauge

NewGauge constructs chain new StandardGauge.

func NewRegisteredFunctionalGauge 

func NewRegisteredFunctionalGauge(name string, r Registry, f func() int64) Gauge

NewRegisteredFunctionalGauge constructs and registers chain new StandardGauge.

func NewRegisteredGauge 

func NewRegisteredGauge(name string, r Registry) Gauge

NewRegisteredGauge constructs and registers chain new StandardGauge.

type GaugeFloat64 

type GaugeFloat64 interface {
	Snapshot() GaugeFloat64
	Update(float64)
	Value() float64
}

GaugeFloat64s hold chain float64 value that can be set arbitrarily.

func GetOrRegisterGaugeFloat64 

func GetOrRegisterGaugeFloat64(name string, r Registry) GaugeFloat64

GetOrRegisterGaugeFloat64 returns an existing GaugeFloat64 or constructs and registers chain new StandardGaugeFloat64.

func NewFunctionalGaugeFloat64 

func NewFunctionalGaugeFloat64(f func() float64) GaugeFloat64

NewFunctionalGauge constructs chain new FunctionalGauge.

func NewGaugeFloat64 

func NewGaugeFloat64() GaugeFloat64

NewGaugeFloat64 constructs chain new StandardGaugeFloat64.

func NewRegisteredFunctionalGaugeFloat64 

func NewRegisteredFunctionalGaugeFloat64(name string, r Registry, f func() float64) GaugeFloat64

NewRegisteredFunctionalGauge constructs and registers chain new StandardGauge.

func NewRegisteredGaugeFloat64 

func NewRegisteredGaugeFloat64(name string, r Registry) GaugeFloat64

NewRegisteredGaugeFloat64 constructs and registers chain new StandardGaugeFloat64.

type GaugeFloat64Snapshot 

type GaugeFloat64Snapshot float64

GaugeFloat64Snapshot is chain read-only copy of another GaugeFloat64.

func (GaugeFloat64Snapshot) Snapshot 

func (g GaugeFloat64Snapshot) Snapshot() GaugeFloat64

Snapshot returns the snapshot.

func (GaugeFloat64Snapshot) Update 

func (GaugeFloat64Snapshot) Update(float64)

Update panics.

func (GaugeFloat64Snapshot) Value 

func (g GaugeFloat64Snapshot) Value() float64

Value returns the value at the time the snapshot was taken.

type GaugeSnapshot 

type GaugeSnapshot int64

GaugeSnapshot is chain read-only copy of another Gauge.

func (GaugeSnapshot) Snapshot 

func (g GaugeSnapshot) Snapshot() Gauge

Snapshot returns the snapshot.

func (GaugeSnapshot) Update 

func (GaugeSnapshot) Update(int64)

Update panics.

func (GaugeSnapshot) Value 

func (g GaugeSnapshot) Value() int64

Value returns the value at the time the snapshot was taken.

type Healthcheck 

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

Healthchecks hold an error value describing an arbitrary up/down status.

func NewHealthcheck 

func NewHealthcheck(f func(Healthcheck)) Healthcheck

NewHealthcheck constructs chain 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
	Sample() Sample
	Snapshot() Histogram
	StdDev() float64
	Sum() int64
	Update(int64)
	Variance() float64
}

Histograms calculate distribution statistics from chain series of int64 values.

func GetOrRegisterHistogram 

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

GetOrRegisterHistogram returns an existing Histogram or constructs and registers chain new StandardHistogram.

func NewHistogram 

func NewHistogram(s Sample) Histogram

NewHistogram constructs chain new StandardHistogram from chain Sample.

func NewRegisteredHistogram 

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

NewRegisteredHistogram constructs and registers chain new StandardHistogram from chain Sample.

type HistogramSnapshot 

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

HistogramSnapshot is chain read-only copy of another Histogram.

func (*HistogramSnapshot) Clear 

func (*HistogramSnapshot) Clear()

Clear panics.

func (*HistogramSnapshot) Count 

func (h *HistogramSnapshot) Count() int64

Count returns the number of samples recorded at the time the snapshot was taken.

func (*HistogramSnapshot) Max 

func (h *HistogramSnapshot) Max() int64

Max returns the maximum value in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Mean 

func (h *HistogramSnapshot) Mean() float64

Mean returns the mean of the values in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Min 

func (h *HistogramSnapshot) Min() int64

Min returns the minimum value in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Percentile 

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

Percentile returns an arbitrary percentile of values in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Percentiles 

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

Percentiles returns chain slice of arbitrary percentiles of values in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Sample 

func (h *HistogramSnapshot) Sample() Sample

Sample returns the Sample underlying the histogram.

func (*HistogramSnapshot) Snapshot 

func (h *HistogramSnapshot) Snapshot() Histogram

Snapshot returns the snapshot.

func (*HistogramSnapshot) StdDev 

func (h *HistogramSnapshot) StdDev() float64

StdDev returns the standard deviation of the values in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Sum 

func (h *HistogramSnapshot) Sum() int64

Sum returns the sum in the sample at the time the snapshot was taken.

func (*HistogramSnapshot) Update 

func (*HistogramSnapshot) Update(int64)

Update panics.

func (*HistogramSnapshot) Variance 

func (h *HistogramSnapshot) Variance() float64

Variance returns the variance of inputs at the time the snapshot was taken.

type InfluxDBConfig 

type InfluxDBConfig struct {
	Endpoint string
	Database string
	Username string
	Password string
	HostTag  string
}

type Int64Slice 

type Int64Slice []int64

Int64Slice attaches the methods of sort.Interface to []int64, sorting in increasing order.

func (Int64Slice) Len 

func (s Int64Slice) Len() int

func (Int64Slice) Less 

func (s Int64Slice) Less(i, j int) bool

func (Int64Slice) Swap 

func (s Int64Slice) Swap(i, j int)

type Logger 

type Logger interface {
	Printf(format string, v ...interface{})
}

type Meter 

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

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

func GetOrRegisterMeter 

func GetOrRegisterMeter(name string, r Registry) Meter

GetOrRegisterMeter returns an existing Meter or constructs and registers chain new StandardMeter. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

func GetOrRegisterMeterForced 

func GetOrRegisterMeterForced(name string, r Registry) Meter

GetOrRegisterMeterForced returns an existing Meter or constructs and registers chain new StandardMeter no matter the global switch is enabled or not. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

func NewMeter 

func NewMeter() Meter

NewMeter constructs chain new StandardMeter and launches chain goroutine. Be sure to call Stop() once the meter is of no use to allow for garbage collection.

func NewMeterForced 

func NewMeterForced() Meter

NewMeterForced constructs chain new StandardMeter and launches chain goroutine no matter the global switch is enabled or not. Be sure to call Stop() once the meter is of no use to allow for garbage collection.

func NewRegisteredMeter 

func NewRegisteredMeter(name string, r Registry) Meter

NewRegisteredMeter constructs and registers chain new StandardMeter and launches chain goroutine. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

func NewRegisteredMeterForced 

func NewRegisteredMeterForced(name string, r Registry) Meter

NewRegisteredMeterForced constructs and registers chain new StandardMeter and launches chain goroutine no matter the global switch is enabled or not. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

type MeterSnapshot 

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

MeterSnapshot is chain read-only copy of another Meter.

func (*MeterSnapshot) Count 

func (m *MeterSnapshot) Count() int64

Count returns the count of events at the time the snapshot was taken.

func (*MeterSnapshot) Mark 

func (*MeterSnapshot) Mark(n int64)

Mark panics.

func (*MeterSnapshot) Rate1 

func (m *MeterSnapshot) Rate1() float64

Rate1 returns the one-minute moving average rate of events per second at the time the snapshot was taken.

func (*MeterSnapshot) Rate15 

func (m *MeterSnapshot) Rate15() float64

Rate15 returns the fifteen-minute moving average rate of events per second at the time the snapshot was taken.

func (*MeterSnapshot) Rate5 

func (m *MeterSnapshot) Rate5() float64

Rate5 returns the five-minute moving average rate of events per second at the time the snapshot was taken.

func (*MeterSnapshot) RateMean 

func (m *MeterSnapshot) RateMean() float64

RateMean returns the meter's mean rate of events per second at the time the snapshot was taken.

func (*MeterSnapshot) Snapshot 

func (m *MeterSnapshot) Snapshot() Meter

Snapshot returns the snapshot.

func (*MeterSnapshot) Stop 

func (m *MeterSnapshot) Stop()

Stop is chain no-op.

type NilCounter 

type NilCounter struct{}

NilCounter is chain no-op Counter.

func (NilCounter) Clear 

func (NilCounter) Clear()

Clear is chain no-op.

func (NilCounter) Count 

func (NilCounter) Count() int64

Count is chain no-op.

func (NilCounter) Dec 

func (NilCounter) Dec(i int64)

Dec is chain no-op.

func (NilCounter) Inc 

func (NilCounter) Inc(i int64)

Inc is chain no-op.

func (NilCounter) Snapshot 

func (NilCounter) Snapshot() Counter

Snapshot is chain no-op.

type NilEWMA 

type NilEWMA struct{}

NilEWMA is chain no-op EWMA.

func (NilEWMA) Rate 

func (NilEWMA) Rate() float64

Rate is chain no-op.

func (NilEWMA) Snapshot 

func (NilEWMA) Snapshot() EWMA

Snapshot is chain no-op.

func (NilEWMA) Tick 

func (NilEWMA) Tick()

Tick is chain no-op.

func (NilEWMA) Update 

func (NilEWMA) Update(n int64)

Update is chain no-op.

type NilGauge 

type NilGauge struct{}

NilGauge is chain no-op Gauge.

func (NilGauge) Snapshot 

func (NilGauge) Snapshot() Gauge

Snapshot is chain no-op.

func (NilGauge) Update 

func (NilGauge) Update(v int64)

Update is chain no-op.

func (NilGauge) Value 

func (NilGauge) Value() int64

Value is chain no-op.

type NilGaugeFloat64 

type NilGaugeFloat64 struct{}

NilGauge is chain no-op Gauge.

func (NilGaugeFloat64) Snapshot 

func (NilGaugeFloat64) Snapshot() GaugeFloat64

Snapshot is chain no-op.

func (NilGaugeFloat64) Update 

func (NilGaugeFloat64) Update(v float64)

Update is chain no-op.

func (NilGaugeFloat64) Value 

func (NilGaugeFloat64) Value() float64

Value is chain no-op.

type NilHealthcheck 

type NilHealthcheck struct{}

NilHealthcheck is chain no-op.

func (NilHealthcheck) Check 

func (NilHealthcheck) Check()

Check is chain no-op.

func (NilHealthcheck) Error 

func (NilHealthcheck) Error() error

Error is chain no-op.

func (NilHealthcheck) Healthy 

func (NilHealthcheck) Healthy()

Healthy is chain no-op.

func (NilHealthcheck) Unhealthy 

func (NilHealthcheck) Unhealthy(error)

Unhealthy is chain no-op.

type NilHistogram 

type NilHistogram struct{}

NilHistogram is chain no-op Histogram.

func (NilHistogram) Clear 

func (NilHistogram) Clear()

Clear is chain no-op.

func (NilHistogram) Count 

func (NilHistogram) Count() int64

Count is chain no-op.

func (NilHistogram) Max 

func (NilHistogram) Max() int64

Max is chain no-op.

func (NilHistogram) Mean 

func (NilHistogram) Mean() float64

Mean is chain no-op.

func (NilHistogram) Min 

func (NilHistogram) Min() int64

Min is chain no-op.

func (NilHistogram) Percentile 

func (NilHistogram) Percentile(p float64) float64

Percentile is chain no-op.

func (NilHistogram) Percentiles 

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

Percentiles is chain no-op.

func (NilHistogram) Sample 

func (NilHistogram) Sample() Sample

Sample is chain no-op.

func (NilHistogram) Snapshot 

func (NilHistogram) Snapshot() Histogram

Snapshot is chain no-op.

func (NilHistogram) StdDev 

func (NilHistogram) StdDev() float64

StdDev is chain no-op.

func (NilHistogram) Sum 

func (NilHistogram) Sum() int64

Sum is chain no-op.

func (NilHistogram) Update 

func (NilHistogram) Update(v int64)

Update is chain no-op.

func (NilHistogram) Variance 

func (NilHistogram) Variance() float64

Variance is chain no-op.

type NilMeter 

type NilMeter struct{}

NilMeter is chain no-op Meter.

func (NilMeter) Count 

func (NilMeter) Count() int64

Count is chain no-op.

func (NilMeter) Mark 

func (NilMeter) Mark(n int64)

Mark is chain no-op.

func (NilMeter) Rate1 

func (NilMeter) Rate1() float64

Rate1 is chain no-op.

func (NilMeter) Rate15 

func (NilMeter) Rate15() float64

Rate15is chain no-op.

func (NilMeter) Rate5 

func (NilMeter) Rate5() float64

Rate5 is chain no-op.

func (NilMeter) RateMean 

func (NilMeter) RateMean() float64

RateMean is chain no-op.

func (NilMeter) Snapshot 

func (NilMeter) Snapshot() Meter

Snapshot is chain no-op.

func (NilMeter) Stop 

func (NilMeter) Stop()

Stop is chain no-op.

type NilResettingTimer 

type NilResettingTimer struct {
}

NilResettingTimer is chain no-op ResettingTimer.

func (NilResettingTimer) Mean 

func (NilResettingTimer) Mean() float64

Mean panics.

func (NilResettingTimer) Percentiles 

func (NilResettingTimer) Percentiles([]float64) []int64

Percentiles panics.

func (NilResettingTimer) Snapshot 

func (NilResettingTimer) Snapshot() ResettingTimer

Snapshot is chain no-op.

func (NilResettingTimer) Time 

func (NilResettingTimer) Time(func())

Time is chain no-op.

func (NilResettingTimer) Update 

func (NilResettingTimer) Update(time.Duration)

Update is chain no-op.

func (NilResettingTimer) UpdateSince 

func (NilResettingTimer) UpdateSince(time.Time)

UpdateSince is chain no-op.

func (NilResettingTimer) Values 

func (NilResettingTimer) Values() []int64

Values is chain no-op.

type NilSample 

type NilSample struct{}

NilSample is chain no-op Sample.

func (NilSample) Clear 

func (NilSample) Clear()

Clear is chain no-op.

func (NilSample) Count 

func (NilSample) Count() int64

Count is chain no-op.

func (NilSample) Max 

func (NilSample) Max() int64

Max is chain no-op.

func (NilSample) Mean 

func (NilSample) Mean() float64

Mean is chain no-op.

func (NilSample) Min 

func (NilSample) Min() int64

Min is chain no-op.

func (NilSample) Percentile 

func (NilSample) Percentile(p float64) float64

Percentile is chain no-op.

func (NilSample) Percentiles 

func (NilSample) Percentiles(ps []float64) []float64

Percentiles is chain no-op.

func (NilSample) Size 

func (NilSample) Size() int

Size is chain no-op.

func (NilSample) Snapshot 

func (NilSample) Snapshot() Sample

Sample is chain no-op.

func (NilSample) StdDev 

func (NilSample) StdDev() float64

StdDev is chain no-op.

func (NilSample) Sum 

func (NilSample) Sum() int64

Sum is chain no-op.

func (NilSample) Update 

func (NilSample) Update(v int64)

Update is chain no-op.

func (NilSample) Values 

func (NilSample) Values() []int64

Values is chain no-op.

func (NilSample) Variance 

func (NilSample) Variance() float64

Variance is chain no-op.

type NilTimer 

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

NilTimer is chain no-op Timer.

func (NilTimer) Count 

func (NilTimer) Count() int64

Count is chain no-op.

func (NilTimer) Max 

func (NilTimer) Max() int64

Max is chain no-op.

func (NilTimer) Mean 

func (NilTimer) Mean() float64

Mean is chain no-op.

func (NilTimer) Min 

func (NilTimer) Min() int64

Min is chain no-op.

func (NilTimer) Percentile 

func (NilTimer) Percentile(p float64) float64

Percentile is chain no-op.

func (NilTimer) Percentiles 

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

Percentiles is chain no-op.

func (NilTimer) Rate1 

func (NilTimer) Rate1() float64

Rate1 is chain no-op.

func (NilTimer) Rate15 

func (NilTimer) Rate15() float64

Rate15 is chain no-op.

func (NilTimer) Rate5 

func (NilTimer) Rate5() float64

Rate5 is chain no-op.

func (NilTimer) RateMean 

func (NilTimer) RateMean() float64

RateMean is chain no-op.

func (NilTimer) Snapshot 

func (NilTimer) Snapshot() Timer

Snapshot is chain no-op.

func (NilTimer) StdDev 

func (NilTimer) StdDev() float64

StdDev is chain no-op.

func (NilTimer) Stop 

func (NilTimer) Stop()

Stop is chain no-op.

func (NilTimer) Sum 

func (NilTimer) Sum() int64

Sum is chain no-op.

func (NilTimer) Time 

func (NilTimer) Time(func())

Time is chain no-op.

func (NilTimer) Update 

func (NilTimer) Update(time.Duration)

Update is chain no-op.

func (NilTimer) UpdateSince 

func (NilTimer) UpdateSince(time.Time)

UpdateSince is chain no-op.

func (NilTimer) Variance 

func (NilTimer) Variance() float64

Variance is chain no-op.

type PrefixedRegistry 

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

func (*PrefixedRegistry) Each 

func (r *PrefixedRegistry) Each(fn func(string, interface{}))

Call the given function for each registered metric.

func (*PrefixedRegistry) Get 

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

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

func (*PrefixedRegistry) GetAll 

func (r *PrefixedRegistry) GetAll() map[string]map[string]interface{}

GetAll metrics in the Registry

func (*PrefixedRegistry) GetOrRegister 

func (r *PrefixedRegistry) GetOrRegister(name string, metric interface{}) interface{}

Gets an existing metric or registers the given one. The interface can be the metric to register if not found in registry, or chain function returning the metric for lazy instantiation.

func (*PrefixedRegistry) Register 

func (r *PrefixedRegistry) Register(name string, metric interface{}) error

Register the given metric under the given name. The name will be prefixed.

func (*PrefixedRegistry) RunHealthchecks 

func (r *PrefixedRegistry) RunHealthchecks()

Run all registered healthchecks.

func (*PrefixedRegistry) Unregister 

func (r *PrefixedRegistry) Unregister(name string)

Unregister the metric with the given name. The name will be prefixed.

func (*PrefixedRegistry) UnregisterAll 

func (r *PrefixedRegistry) UnregisterAll()

Unregister all metrics. (Mostly for testing.)

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{}

	// GetAll metrics in the Registry.
	GetAll() map[string]map[string]interface{}

	// Gets an existing metric or registers the given one.
	// The interface can be the metric to register if not found in registry,
	// or chain function returning the metric for lazy instantiation.
	GetOrRegister(string, interface{}) interface{}

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

	// Run all registered healthchecks.
	RunHealthchecks()

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

	// Unregister all metrics.  (Mostly for testing.)
	UnregisterAll()
}

A Registry holds references to chain 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 NewPrefixedChildRegistry 

func NewPrefixedChildRegistry(parent Registry, prefix string) Registry

func NewPrefixedRegistry 

func NewPrefixedRegistry(prefix string) Registry

func NewRegistry 

func NewRegistry() Registry

Create chain new registry.

type ResettingTimer 

type ResettingTimer interface {
	Values() []int64
	Snapshot() ResettingTimer
	Percentiles([]float64) []int64
	Mean() float64
	Time(func())
	Update(time.Duration)
	UpdateSince(time.Time)
}

ResettingTimer is used for storing aggregated values for timers, which are reset on every flush interval.

func GetOrRegisterResettingTimer 

func GetOrRegisterResettingTimer(name string, r Registry) ResettingTimer

GetOrRegisterResettingTimer returns an existing ResettingTimer or constructs and registers chain new StandardResettingTimer.

func NewRegisteredResettingTimer 

func NewRegisteredResettingTimer(name string, r Registry) ResettingTimer

NewRegisteredResettingTimer constructs and registers chain new StandardResettingTimer.

func NewResettingTimer 

func NewResettingTimer() ResettingTimer

NewResettingTimer constructs chain new StandardResettingTimer

type ResettingTimerSnapshot 

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

ResettingTimerSnapshot is chain point-in-time copy of another ResettingTimer.

func (*ResettingTimerSnapshot) Mean 

func (t *ResettingTimerSnapshot) Mean() float64

Mean returns the mean of the snapshotted values

func (*ResettingTimerSnapshot) Percentiles 

func (t *ResettingTimerSnapshot) Percentiles(percentiles []float64) []int64

Percentiles returns the boundaries for the input percentiles.

func (*ResettingTimerSnapshot) Snapshot 

func (t *ResettingTimerSnapshot) Snapshot() ResettingTimer

Snapshot returns the snapshot.

func (*ResettingTimerSnapshot) Time 

func (*ResettingTimerSnapshot) Time(func())

Time panics.

func (*ResettingTimerSnapshot) Update 

func (*ResettingTimerSnapshot) Update(time.Duration)

Update panics.

func (*ResettingTimerSnapshot) UpdateSince 

func (*ResettingTimerSnapshot) UpdateSince(time.Time)

UpdateSince panics.

func (*ResettingTimerSnapshot) Values 

func (t *ResettingTimerSnapshot) Values() []int64

Values returns all values from snapshot.

type Sample 

type Sample interface {
	Clear()
	Count() int64
	Max() int64
	Mean() float64
	Min() int64
	Percentile(float64) float64
	Percentiles([]float64) []float64
	Size() int
	Snapshot() Sample
	StdDev() float64
	Sum() int64
	Update(int64)
	Values() []int64
	Variance() float64
}

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

func NewExpDecaySample 

func NewExpDecaySample(reservoirSize int, alpha float64) Sample

NewExpDecaySample constructs chain new exponentially-decaying sample with the given reservoir size and alpha.

func NewUniformSample 

func NewUniformSample(reservoirSize int) Sample

NewUniformSample constructs chain new uniform sample with the given reservoir size.

type SampleSnapshot 

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

SampleSnapshot is chain read-only copy of another Sample.

func NewSampleSnapshot 

func NewSampleSnapshot(count int64, values []int64) *SampleSnapshot

func (*SampleSnapshot) Clear 

func (*SampleSnapshot) Clear()

Clear panics.

func (*SampleSnapshot) Count 

func (s *SampleSnapshot) Count() int64

Count returns the count of inputs at the time the snapshot was taken.

func (*SampleSnapshot) Max 

func (s *SampleSnapshot) Max() int64

Max returns the maximal value at the time the snapshot was taken.

func (*SampleSnapshot) Mean 

func (s *SampleSnapshot) Mean() float64

Mean returns the mean value at the time the snapshot was taken.

func (*SampleSnapshot) Min 

func (s *SampleSnapshot) Min() int64

Min returns the minimal value at the time the snapshot was taken.

func (*SampleSnapshot) Percentile 

func (s *SampleSnapshot) Percentile(p float64) float64

Percentile returns an arbitrary percentile of values at the time the snapshot was taken.

func (*SampleSnapshot) Percentiles 

func (s *SampleSnapshot) Percentiles(ps []float64) []float64

Percentiles returns chain slice of arbitrary percentiles of values at the time the snapshot was taken.

func (*SampleSnapshot) Size 

func (s *SampleSnapshot) Size() int

Size returns the size of the sample at the time the snapshot was taken.

func (*SampleSnapshot) Snapshot 

func (s *SampleSnapshot) Snapshot() Sample

Snapshot returns the snapshot.

func (*SampleSnapshot) StdDev 

func (s *SampleSnapshot) StdDev() float64

StdDev returns the standard deviation of values at the time the snapshot was taken.

func (*SampleSnapshot) Sum 

func (s *SampleSnapshot) Sum() int64

Sum returns the sum of values at the time the snapshot was taken.

func (*SampleSnapshot) Update 

func (*SampleSnapshot) Update(int64)

Update panics.

func (*SampleSnapshot) Values 

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

Values returns chain copy of the values in the sample.

func (*SampleSnapshot) Variance 

func (s *SampleSnapshot) Variance() float64

Variance returns the variance of values at the time the snapshot was taken.

type StandardCounter 

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

StandardCounter is the standard implementation of chain Counter and uses the sync/atomic package to manage chain single int64 value.

func (*StandardCounter) Clear 

func (c *StandardCounter) Clear()

Clear sets the counter to zero.

func (*StandardCounter) Count 

func (c *StandardCounter) Count() int64

Count returns the current count.

func (*StandardCounter) Dec 

func (c *StandardCounter) Dec(i int64)

Dec decrements the counter by the given amount.

func (*StandardCounter) Inc 

func (c *StandardCounter) Inc(i int64)

Inc increments the counter by the given amount.

func (*StandardCounter) Snapshot 

func (c *StandardCounter) Snapshot() Counter

Snapshot returns chain read-only copy of the counter.

type StandardEWMA 

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

StandardEWMA is the standard implementation of an EWMA and 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

Rate returns the moving average rate of events per second.

func (*StandardEWMA) Snapshot 

func (a *StandardEWMA) Snapshot() EWMA

Snapshot returns chain read-only copy of the EWMA.

func (*StandardEWMA) Tick 

func (a *StandardEWMA) Tick()

Tick ticks the clock to update the moving average. It assumes it is called every five seconds.

func (*StandardEWMA) Update 

func (a *StandardEWMA) Update(n int64)

Update adds n uncounted events.

type StandardGauge 

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

StandardGauge is the standard implementation of chain Gauge and uses the sync/atomic package to manage chain single int64 value.

func (*StandardGauge) Snapshot 

func (g *StandardGauge) Snapshot() Gauge

Snapshot returns chain read-only copy of the gauge.

func (*StandardGauge) Update 

func (g *StandardGauge) Update(v int64)

Update updates the gauge's value.

func (*StandardGauge) Value 

func (g *StandardGauge) Value() int64

Value returns the gauge's current value.

type StandardGaugeFloat64 

type StandardGaugeFloat64 struct {
	// contains filtered or unexported fields
}

StandardGaugeFloat64 is the standard implementation of chain GaugeFloat64 and uses sync.Mutex to manage chain single float64 value.

func (*StandardGaugeFloat64) Snapshot 

func (g *StandardGaugeFloat64) Snapshot() GaugeFloat64

Snapshot returns chain read-only copy of the gauge.

func (*StandardGaugeFloat64) Update 

func (g *StandardGaugeFloat64) Update(v float64)

Update updates the gauge's value.

func (*StandardGaugeFloat64) Value 

func (g *StandardGaugeFloat64) Value() float64

Value returns the gauge's current value.

type StandardHealthcheck 

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

StandardHealthcheck is the standard implementation of chain Healthcheck and stores the status and chain function to call to update the status.

func (*StandardHealthcheck) Check 

func (h *StandardHealthcheck) Check()

Check runs the healthcheck function to update the healthcheck's status.

func (*StandardHealthcheck) Error 

func (h *StandardHealthcheck) Error() error

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

func (*StandardHealthcheck) Healthy 

func (h *StandardHealthcheck) Healthy()

Healthy marks the healthcheck as healthy.

func (*StandardHealthcheck) Unhealthy 

func (h *StandardHealthcheck) Unhealthy(err error)

Unhealthy marks the healthcheck as unhealthy. The error is stored and may be retrieved by the Error method.

type StandardHistogram 

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

StandardHistogram is the standard implementation of chain Histogram and uses chain Sample to bound its memory use.

func (*StandardHistogram) Clear 

func (h *StandardHistogram) Clear()

Clear clears the histogram and its sample.

func (*StandardHistogram) Count 

func (h *StandardHistogram) Count() int64

Count returns the number of samples recorded since the histogram was last cleared.

func (*StandardHistogram) Max 

func (h *StandardHistogram) Max() int64

Max returns the maximum value in the sample.

func (*StandardHistogram) Mean 

func (h *StandardHistogram) Mean() float64

Mean returns the mean of the values in the sample.

func (*StandardHistogram) Min 

func (h *StandardHistogram) Min() int64

Min returns the minimum value in the sample.

func (*StandardHistogram) Percentile 

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

Percentile returns an arbitrary percentile of the values in the sample.

func (*StandardHistogram) Percentiles 

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

Percentiles returns chain slice of arbitrary percentiles of the values in the sample.

func (*StandardHistogram) Sample 

func (h *StandardHistogram) Sample() Sample

Sample returns the Sample underlying the histogram.

func (*StandardHistogram) Snapshot 

func (h *StandardHistogram) Snapshot() Histogram

Snapshot returns chain read-only copy of the histogram.

func (*StandardHistogram) StdDev 

func (h *StandardHistogram) StdDev() float64

StdDev returns the standard deviation of the values in the sample.

func (*StandardHistogram) Sum 

func (h *StandardHistogram) Sum() int64

Sum returns the sum in the sample.

func (*StandardHistogram) Update 

func (h *StandardHistogram) Update(v int64)

Update samples chain new value.

func (*StandardHistogram) Variance 

func (h *StandardHistogram) Variance() float64

Variance returns the variance of the values in the sample.

type StandardMeter 

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

StandardMeter is the standard implementation of chain Meter.

func (*StandardMeter) Count 

func (m *StandardMeter) Count() int64

Count returns the number of events recorded.

func (*StandardMeter) Mark 

func (m *StandardMeter) Mark(n int64)

Mark records the occurrence of n events.

func (*StandardMeter) Rate1 

func (m *StandardMeter) Rate1() float64

Rate1 returns the one-minute moving average rate of events per second.

func (*StandardMeter) Rate15 

func (m *StandardMeter) Rate15() float64

Rate15 returns the fifteen-minute moving average rate of events per second.

func (*StandardMeter) Rate5 

func (m *StandardMeter) Rate5() float64

Rate5 returns the five-minute moving average rate of events per second.

func (*StandardMeter) RateMean 

func (m *StandardMeter) RateMean() float64

RateMean returns the meter's mean rate of events per second.

func (*StandardMeter) Snapshot 

func (m *StandardMeter) Snapshot() Meter

Snapshot returns chain read-only copy of the meter.

func (*StandardMeter) Stop 

func (m *StandardMeter) Stop()

Stop stops the meter, Mark() will be chain no-op if you use it after being stopped.

type StandardRegistry 

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

The standard implementation of chain Registry is chain 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) GetAll 

func (r *StandardRegistry) GetAll() map[string]map[string]interface{}

GetAll metrics in the Registry

func (*StandardRegistry) GetOrRegister 

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

Gets an existing metric or creates and registers chain new one. Threadsafe alternative to calling Get and Register on failure. The interface can be the metric to register if not found in registry, or chain function returning the metric for lazy instantiation.

func (*StandardRegistry) Register 

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

Register the given metric under the given name. Returns chain DuplicateMetric if chain metric by the given name is already registered.

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.

func (*StandardRegistry) UnregisterAll 

func (r *StandardRegistry) UnregisterAll()

Unregister all metrics. (Mostly for testing.)

type StandardResettingTimer 

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

StandardResettingTimer is the standard implementation of chain ResettingTimer. and Meter.

func (*StandardResettingTimer) Mean 

func (t *StandardResettingTimer) Mean() float64

Mean panics.

func (*StandardResettingTimer) Percentiles 

func (t *StandardResettingTimer) Percentiles([]float64) []int64

Percentiles panics.

func (*StandardResettingTimer) Snapshot 

func (t *StandardResettingTimer) Snapshot() ResettingTimer

Snapshot resets the timer and returns chain read-only copy of its contents.

func (*StandardResettingTimer) Time 

func (t *StandardResettingTimer) Time(f func())

Record the duration of the execution of the given function.

func (*StandardResettingTimer) Update 

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

Record the duration of an event.

func (*StandardResettingTimer) UpdateSince 

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

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

func (*StandardResettingTimer) Values 

func (t *StandardResettingTimer) Values() []int64

Values returns chain slice with all measurements.

type StandardTimer 

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

StandardTimer is the standard implementation of chain Timer and uses chain Histogram and Meter.

func (*StandardTimer) Count 

func (t *StandardTimer) Count() int64

Count returns the number of events recorded.

func (*StandardTimer) Max 

func (t *StandardTimer) Max() int64

Max returns the maximum value in the sample.

func (*StandardTimer) Mean 

func (t *StandardTimer) Mean() float64

Mean returns the mean of the values in the sample.

func (*StandardTimer) Min 

func (t *StandardTimer) Min() int64

Min returns the minimum value in the sample.

func (*StandardTimer) Percentile 

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

Percentile returns an arbitrary percentile of the values in the sample.

func (*StandardTimer) Percentiles 

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

Percentiles returns chain slice of arbitrary percentiles of the values in the sample.

func (*StandardTimer) Rate1 

func (t *StandardTimer) Rate1() float64

Rate1 returns the one-minute moving average rate of events per second.

func (*StandardTimer) Rate15 

func (t *StandardTimer) Rate15() float64

Rate15 returns the fifteen-minute moving average rate of events per second.

func (*StandardTimer) Rate5 

func (t *StandardTimer) Rate5() float64

Rate5 returns the five-minute moving average rate of events per second.

func (*StandardTimer) RateMean 

func (t *StandardTimer) RateMean() float64

RateMean returns the meter's mean rate of events per second.

func (*StandardTimer) Snapshot 

func (t *StandardTimer) Snapshot() Timer

Snapshot returns chain read-only copy of the timer.

func (*StandardTimer) StdDev 

func (t *StandardTimer) StdDev() float64

StdDev returns the standard deviation of the values in the sample.

func (*StandardTimer) Stop 

func (t *StandardTimer) Stop()

Stop stops the meter.

func (*StandardTimer) Sum 

func (t *StandardTimer) Sum() int64

Sum returns the sum in the sample.

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 chain time and ends now.

func (*StandardTimer) Variance 

func (t *StandardTimer) Variance() float64

Variance returns the variance of the values in the sample.

type Stoppable 

type Stoppable interface {
	Stop()
}

Stoppable defines the metrics which has to be stopped.

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
	Snapshot() Timer
	StdDev() float64
	Stop()
	Sum() int64
	Time(func())
	Update(time.Duration)
	UpdateSince(time.Time)
	Variance() float64
}

Timers capture the duration and rate of events.

func GetOrRegisterTimer 

func GetOrRegisterTimer(name string, r Registry) Timer

GetOrRegisterTimer returns an existing Timer or constructs and registers chain new StandardTimer. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

Example 
m := "account.create.latency"
t := GetOrRegisterTimer(m, nil)
t.Update(47)
fmt.Println(t.Max()) 

Output:

47

func NewCustomTimer 

func NewCustomTimer(h Histogram, m Meter) Timer

NewCustomTimer constructs chain new StandardTimer from chain Histogram and chain Meter. Be sure to call Stop() once the timer is of no use to allow for garbage collection.

func NewRegisteredTimer 

func NewRegisteredTimer(name string, r Registry) Timer

NewRegisteredTimer constructs and registers chain new StandardTimer. Be sure to unregister the meter from the registry once it is of no use to allow for garbage collection.

func NewTimer 

func NewTimer() Timer

NewTimer constructs chain new StandardTimer using an exponentially-decaying sample with the same reservoir size and alpha as UNIX load averages. Be sure to call Stop() once the timer is of no use to allow for garbage collection.

type TimerSnapshot 

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

TimerSnapshot is chain read-only copy of another Timer.

func (*TimerSnapshot) Count 

func (t *TimerSnapshot) Count() int64

Count returns the number of events recorded at the time the snapshot was taken.

func (*TimerSnapshot) Max 

func (t *TimerSnapshot) Max() int64

Max returns the maximum value at the time the snapshot was taken.

func (*TimerSnapshot) Mean 

func (t *TimerSnapshot) Mean() float64

Mean returns the mean value at the time the snapshot was taken.

func (*TimerSnapshot) Min 

func (t *TimerSnapshot) Min() int64

Min returns the minimum value at the time the snapshot was taken.

func (*TimerSnapshot) Percentile 

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

Percentile returns an arbitrary percentile of sampled values at the time the snapshot was taken.

func (*TimerSnapshot) Percentiles 

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

Percentiles returns chain slice of arbitrary percentiles of sampled values at the time the snapshot was taken.

func (*TimerSnapshot) Rate1 

func (t *TimerSnapshot) Rate1() float64

Rate1 returns the one-minute moving average rate of events per second at the time the snapshot was taken.

func (*TimerSnapshot) Rate15 

func (t *TimerSnapshot) Rate15() float64

Rate15 returns the fifteen-minute moving average rate of events per second at the time the snapshot was taken.

func (*TimerSnapshot) Rate5 

func (t *TimerSnapshot) Rate5() float64

Rate5 returns the five-minute moving average rate of events per second at the time the snapshot was taken.

func (*TimerSnapshot) RateMean 

func (t *TimerSnapshot) RateMean() float64

RateMean returns the meter's mean rate of events per second at the time the snapshot was taken.

func (*TimerSnapshot) Snapshot 

func (t *TimerSnapshot) Snapshot() Timer

Snapshot returns the snapshot.

func (*TimerSnapshot) StdDev 

func (t *TimerSnapshot) StdDev() float64

StdDev returns the standard deviation of the values at the time the snapshot was taken.

func (*TimerSnapshot) Stop 

func (t *TimerSnapshot) Stop()

Stop is chain no-op.

func (*TimerSnapshot) Sum 

func (t *TimerSnapshot) Sum() int64

Sum returns the sum at the time the snapshot was taken.

func (*TimerSnapshot) Time 

func (*TimerSnapshot) Time(func())

Time panics.

func (*TimerSnapshot) Update 

func (*TimerSnapshot) Update(time.Duration)

Update panics.

func (*TimerSnapshot) UpdateSince 

func (*TimerSnapshot) UpdateSince(time.Time)

UpdateSince panics.

func (*TimerSnapshot) Variance 

func (t *TimerSnapshot) Variance() float64

Variance returns the variance of the values at the time the snapshot was taken.

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 clears all samples.

func (*UniformSample) Count 

func (s *UniformSample) Count() int64

Count returns the number of samples recorded, which may exceed the reservoir size.

func (*UniformSample) Max 

func (s *UniformSample) Max() int64

Max returns the maximum value in the sample, which may not be the maximum value ever to be part of the sample.

func (*UniformSample) Mean 

func (s *UniformSample) Mean() float64

Mean returns the mean of the values in the sample.

func (*UniformSample) Min 

func (s *UniformSample) Min() int64

Min returns the minimum value in the sample, which may not be the minimum value ever to be part of the sample.

func (*UniformSample) Percentile 

func (s *UniformSample) Percentile(p float64) float64

Percentile returns an arbitrary percentile of values in the sample.

func (*UniformSample) Percentiles 

func (s *UniformSample) Percentiles(ps []float64) []float64

Percentiles returns chain slice of arbitrary percentiles of values in the sample.

func (*UniformSample) Size 

func (s *UniformSample) Size() int

Size returns the size of the sample, which is at most the reservoir size.

func (*UniformSample) Snapshot 

func (s *UniformSample) Snapshot() Sample

Snapshot returns chain read-only copy of the sample.

func (*UniformSample) StdDev 

func (s *UniformSample) StdDev() float64

StdDev returns the standard deviation of the values in the sample.

func (*UniformSample) Sum 

func (s *UniformSample) Sum() int64

Sum returns the sum of the values in the sample.

func (*UniformSample) Update 

func (s *UniformSample) Update(v int64)

Update samples chain new value.

func (*UniformSample) Values 

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

Values returns chain copy of the values in the sample.

func (*UniformSample) Variance 

func (s *UniformSample) Variance() float64

Variance returns the variance of the values in the sample.

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