metrics

Documentation

Overview

Package metrics provides functions for collecting and managing metrics through different metrics libraries.

Metrics library implementations must implement the Registry interface in the package.

Index

• Constants
• func TargetName(service, host, path string, targetURL *url.URL) (string, error)
• type Counter
• type NoopCounter
  • func (c NoopCounter) Inc(n int64)
• type NoopRegistry
  • func (p NoopRegistry) GetCounter(name string) Counter
  • func (p NoopRegistry) GetTimer(name string) Timer
  • func (p NoopRegistry) Names() []string
  • func (p NoopRegistry) Unregister(name string)
  • func (p NoopRegistry) UnregisterAll()
• type NoopTimer
  • func (t NoopTimer) Percentile(nth float64) float64
  • func (t NoopTimer) Rate1() float64
  • func (t NoopTimer) UpdateSince(start time.Time)
• type Registry
  • func NewRegistry(cfg config.Metrics) (r Registry, err error)
• type Timer

Constants

const DefaultNames = "{{clean .Service}}.{{clean .Host}}.{{clean .Path}}.{{clean .TargetURL.Host}}"

DefaultNames contains the default template for route metric names.

const DefaultPrefix = "{{clean .Hostname}}.{{clean .Exec}}"

DefaulPrefix contains the default template for metrics prefix.

Functions

func TargetName

func TargetName(service, host, path string, targetURL *url.URL) (string, error)

TargetName returns the metrics name from the given parameters.

Types

type Counter

type Counter interface {
	// Inc increases the counter value by 'n'.
	Inc(n int64)
}

Counter defines a metric for counting events.

type NoopCounter

type NoopCounter struct{}

NoopCounter is a stub implementation of the Counter interface.

func (NoopCounter) Inc

func (c NoopCounter) Inc(n int64)

type NoopRegistry

type NoopRegistry struct{}

NoopRegistry is a stub implementation of the Registry interface.

func (NoopRegistry) GetCounter

func (p NoopRegistry) GetCounter(name string) Counter

func (NoopRegistry) GetTimer

func (p NoopRegistry) GetTimer(name string) Timer

func (NoopRegistry) Names

func (p NoopRegistry) Names() []string

func (NoopRegistry) Unregister

func (p NoopRegistry) Unregister(name string)

func (NoopRegistry) UnregisterAll

func (p NoopRegistry) UnregisterAll()

type NoopTimer

type NoopTimer struct{}

NoopTimer is a stub implementation of the Timer interface.

func (NoopTimer) Percentile

func (t NoopTimer) Percentile(nth float64) float64

func (NoopTimer) Rate1

func (t NoopTimer) Rate1() float64

func (NoopTimer) UpdateSince

func (t NoopTimer) UpdateSince(start time.Time)

type Registry

type Registry interface {
	// Names returns the list of registered metrics acquired
	// through the GetXXX() functions. It should return them
	// sorted in alphabetical order.
	Names() []string

	// Unregister removes the registered metric and stops
	// reporting it to an external backend.
	Unregister(name string)

	// UnregisterAll removes all registered metrics and stops
	// reporting  them to an external backend.
	UnregisterAll()

	// GetCounter returns a counter metric for the given name.
	// If the metric does not exist yet it should be created
	// otherwise the existing metric should be returned.
	GetCounter(name string) Counter

	// GetTimer returns a timer metric for the given name.
	// If the metric does not exist yet it should be created
	// otherwise the existing metric should be returned.
	GetTimer(name string) Timer
}

Registry defines an interface for metrics values which can be implemented by different metrics libraries. An implementation must be safe to be used by multiple go routines.

var DefaultRegistry Registry = NoopRegistry{}

DefaultRegistry stores the metrics library provider.

func NewRegistry

func NewRegistry(cfg config.Metrics) (r Registry, err error)

NewRegistry creates a new metrics registry.

type Timer

type Timer interface {
	// Percentile returns the nth percentile of the duration.
	Percentile(nth float64) float64

	// Rate1 returns the 1min rate.
	Rate1() float64

	// UpdateSince counts an event and records the duration
	// as the delta between 'start' and the function is called.
	UpdateSince(start time.Time)
}

Timer defines a metric for counting and timing durations for events.