metrics

Documentation

Overview

Package metrics contains a ready to use instance of patan. This instance can be used as the sole active instance of patan within the application. Clients are advised to use this. example: metrics.AddSample("key", 123)

Example

sw := StartStopwatch()

IncrementCounter("active.connections")
AddSample("shopping.basket.total", 143.26)
AddSample("shopping.basket.total", 167.16)
AddSample("shopping.basket.total", 23.98)
DecrementCounter("active.connections")
RecordElapsedTime("order.processing.duration", sw)

snapshot := SnapshotAndReset() //Returns a snapshot of all recorded counters, samples and durations and clears the store!

_ = snapshot.Counters()["active.connections"] // 0    (1 increment, 1 decrement, counters start at 0)

basketTotal := snapshot.Samples()["shopping.basket.total"] // baskedTotal = a distribution with a min, max, avg and stddev
basketTotal.SampleCount()                                  // 3
basketTotal.Avg()                                          // 111,46
basketTotal.StdDev()                                       // ...

processingDuration := snapshot.Durations()["order.processing.duration"] //  returns a distribution as well
processingDuration.SampleCount()                                        // 1
processingDuration.Avg()                                                // ...
//...

timeWindow := snapshot.CreatedTimestamp() - snapshot.StartedTimestamp() // time window in which measurements were recorded in millis
_ = timeWindow

Index

• func AddSample(key string, value float64)
• func AddToCounter(key string, value int64)
• func DecrementCounter(key string)
• func IncrementCounter(key string)
• func MeasureFunc(key string, subject func()) float64
• func MeasureFuncCanPanic(key string, subject func()) float64
• func New() api.Facade
• func RecordElapsedTime(key string, stopwatch api.Stopwatch) float64
• func Reset()
• func Snapshot() api.Snapshot
• func SnapshotAndReset() api.Snapshot
• func StartStopwatch() api.Stopwatch

Examples

• Package

Functions

func AddSample

func AddSample(key string, value float64)

AddSample adds a sample to the distribution identified by value, if the distribution doesn't exist, it will be created

func AddToCounter

func AddToCounter(key string, value int64)

AddToCounter adds value to the counter identified by key, value can be negative

func DecrementCounter

func DecrementCounter(key string)

DecrementCounter decrements the counter identified by key by 1

func IncrementCounter

func IncrementCounter(key string)

IncrementCounter increments the counter identified by key by 1

func MeasureFunc

func MeasureFunc(key string, subject func()) float64

MeasureFunc runs the subject function and records it's execution duration under the distribution identified with key

func MeasureFuncCanPanic

func MeasureFuncCanPanic(key string, subject func()) float64

MeasureFuncCanPanic runs the subject function and records it's execution duration under the distribution identified with key. When subject() panics, the measurement is recored under the same key with .panic appended. This function itself will panic with the same error as the inner function.

func New

func New() api.Facade

New returns a new API facade with a new and empty underlying store.

func RecordElapsedTime

func RecordElapsedTime(key string, stopwatch api.Stopwatch) float64

RecordElapsedTime records the elapsed time of the stopwatch under the distribution identified with key

func Reset

func Reset()

Reset clears the store

func Snapshot

func Snapshot() api.Snapshot

Snapshot returns a snapshot of all the counters, durations and samples recorded since creation or the last reset.

func SnapshotAndReset

func SnapshotAndReset() api.Snapshot

SnapshotAndReset returns a snapshot of all the counters, durations and samples recorded since creation or the last reset, and then clears the internal state

func StartStopwatch

func StartStopwatch() api.Stopwatch

StartStopwatch starts a new stopwatch