rolling

Documentation

Overview

Package rolling contains a MetricsCollector that tracks in memory rolling stats about a circuit.

Index

• type FallbackStats
  • func FindFallbackMetrics(c *circuit.Circuit) *FallbackStats
  • func (r *FallbackStats) ErrConcurrencyLimitReject(_ context.Context, now time.Time)
  • func (r *FallbackStats) ErrFailure(_ context.Context, now time.Time, _ time.Duration)
  • func (r *FallbackStats) SetConfigNotThreadSafe(config FallbackStatsConfig)
  • func (r *FallbackStats) Success(_ context.Context, now time.Time, _ time.Duration)
  • func (r *FallbackStats) Var() expvar.Var
• type FallbackStatsConfig
  • func (r *FallbackStatsConfig) Merge(other FallbackStatsConfig)
• type RunStats
  • func FindCommandMetrics(c *circuit.Circuit) *RunStats
  • func (r *RunStats) Config() RunStatsConfig
  • func (r *RunStats) ErrBadRequest(_ context.Context, now time.Time, duration time.Duration)
  • func (r *RunStats) ErrConcurrencyLimitReject(_ context.Context, now time.Time)
  • func (r *RunStats) ErrFailure(_ context.Context, now time.Time, duration time.Duration)
  • func (r *RunStats) ErrInterrupt(_ context.Context, now time.Time, duration time.Duration)
  • func (r *RunStats) ErrShortCircuit(_ context.Context, now time.Time)
  • func (r *RunStats) ErrTimeout(_ context.Context, now time.Time, duration time.Duration)
  • func (r *RunStats) ErrorPercentage() float64
  • func (r *RunStats) ErrorPercentageAt(now time.Time) float64
  • func (r *RunStats) ErrorsAt(now time.Time) int64
  • func (r *RunStats) LegitimateAttemptsAt(now time.Time) int64
  • func (r *RunStats) SetConfigNotThreadSafe(config RunStatsConfig)
  • func (r *RunStats) Success(_ context.Context, now time.Time, duration time.Duration)
  • func (r *RunStats) Var() expvar.Var
• type RunStatsConfig
  • func (r *RunStatsConfig) Merge(other RunStatsConfig)
• type StatFactory
  • func (s *StatFactory) CreateConfig(circuitName string) circuit.Config
  • func (s *StatFactory) FallbackStats(circuitName string) *FallbackStats
  • func (s *StatFactory) RunStats(circuitName string) *RunStats

Types

type FallbackStats

type FallbackStats struct {
	Successes                  faststats.RollingCounter
	ErrConcurrencyLimitRejects faststats.RollingCounter
	ErrFailures                faststats.RollingCounter
}

FallbackStats tracks fallback metrics in rolling buckets

func FindFallbackMetrics

func FindFallbackMetrics(c *circuit.Circuit) *FallbackStats

FindFallbackMetrics searches a circuit for the previously stored fallback stats. Returns nil if never set.

func (*FallbackStats) ErrConcurrencyLimitReject

func (r *FallbackStats) ErrConcurrencyLimitReject(_ context.Context, now time.Time)

ErrConcurrencyLimitReject increments the ErrConcurrencyLimitReject bucket

func (*FallbackStats) ErrFailure

func (r *FallbackStats) ErrFailure(_ context.Context, now time.Time, _ time.Duration)

ErrFailure increments the ErrFailure bucket

func (*FallbackStats) SetConfigNotThreadSafe

func (r *FallbackStats) SetConfigNotThreadSafe(config FallbackStatsConfig)

SetConfigNotThreadSafe sets the configuration for fallback stats

func (*FallbackStats) Success

func (r *FallbackStats) Success(_ context.Context, now time.Time, _ time.Duration)

Success increments the Success bucket

func (*FallbackStats) Var

func (r *FallbackStats) Var() expvar.Var

Var allows FallbackStats on expvar

type FallbackStatsConfig

type FallbackStatsConfig struct {
	// Rolling Stats size is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingstatstimeinmilliseconds
	RollingStatsDuration time.Duration
	// Now should simulate time.Now
	Now func() time.Time
	// RollingStatsNumBuckets is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingstatsnumbuckets
	RollingStatsNumBuckets int
}

FallbackStatsConfig configures how to track fallback stats

func (*FallbackStatsConfig) Merge

func (r *FallbackStatsConfig) Merge(other FallbackStatsConfig)

Merge this config with another

type RunStats

type RunStats struct {
	Successes                  faststats.RollingCounter
	ErrConcurrencyLimitRejects faststats.RollingCounter
	ErrFailures                faststats.RollingCounter
	ErrShortCircuits           faststats.RollingCounter
	ErrTimeouts                faststats.RollingCounter
	ErrBadRequests             faststats.RollingCounter
	ErrInterrupts              faststats.RollingCounter

	// It is analogous to https://github.com/Netflix/Hystrix/wiki/Metrics-and-Monitoring#latency-percentiles-hystrixcommandrun-execution-gauge
	Latencies faststats.RollingPercentile
	// contains filtered or unexported fields
}

RunStats tracks rolling windows of callback counts

func FindCommandMetrics

func FindCommandMetrics(c *circuit.Circuit) *RunStats

FindCommandMetrics searches a circuit for the previously stored run stats. Returns nil if never set.

func (*RunStats) Config

func (r *RunStats) Config() RunStatsConfig

Config returns the current configuration

func (*RunStats) ErrBadRequest

func (r *RunStats) ErrBadRequest(_ context.Context, now time.Time, duration time.Duration)

ErrBadRequest increments the ErrBadRequest bucket

func (*RunStats) ErrConcurrencyLimitReject

func (r *RunStats) ErrConcurrencyLimitReject(_ context.Context, now time.Time)

ErrConcurrencyLimitReject increments the ErrConcurrencyLimitReject bucket

func (*RunStats) ErrFailure

func (r *RunStats) ErrFailure(_ context.Context, now time.Time, duration time.Duration)

ErrFailure increments the ErrFailure bucket

func (*RunStats) ErrInterrupt

func (r *RunStats) ErrInterrupt(_ context.Context, now time.Time, duration time.Duration)

ErrInterrupt increments the ErrInterrupts bucket

func (*RunStats) ErrShortCircuit

func (r *RunStats) ErrShortCircuit(_ context.Context, now time.Time)

ErrShortCircuit increments the ErrShortCircuit bucket

func (*RunStats) ErrTimeout

func (r *RunStats) ErrTimeout(_ context.Context, now time.Time, duration time.Duration)

ErrTimeout increments the ErrTimeout bucket

func (*RunStats) ErrorPercentage

func (r *RunStats) ErrorPercentage() float64

ErrorPercentage returns [0.0 - 1.0] what % of request are considered failing in the rolling window.

func (*RunStats) ErrorPercentageAt

func (r *RunStats) ErrorPercentageAt(now time.Time) float64

ErrorPercentageAt is [0.0 - 1.0] errors/legitimate

func (*RunStats) ErrorsAt

func (r *RunStats) ErrorsAt(now time.Time) int64

ErrorsAt returns the # of errors at a moment in time (errors are timeouts and failures)

func (*RunStats) LegitimateAttemptsAt

func (r *RunStats) LegitimateAttemptsAt(now time.Time) int64

LegitimateAttemptsAt returns the sum of errors and successes

func (*RunStats) SetConfigNotThreadSafe

func (r *RunStats) SetConfigNotThreadSafe(config RunStatsConfig)

SetConfigNotThreadSafe updates the RunStats buckets

func (*RunStats) Success

func (r *RunStats) Success(_ context.Context, now time.Time, duration time.Duration)

Success increments the Successes bucket

func (*RunStats) Var

func (r *RunStats) Var() expvar.Var

Var allows exposing RunStats on expvar

type RunStatsConfig

type RunStatsConfig struct {
	// Now should simulate time.Now
	Now func() time.Time
	// Rolling Stats size is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingstatstimeinmilliseconds
	RollingStatsDuration time.Duration
	// RollingStatsNumBuckets is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingstatsnumbuckets
	RollingStatsNumBuckets int
	// RollingPercentileDuration is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingpercentiletimeinmilliseconds
	RollingPercentileDuration time.Duration
	// RollingPercentileNumBuckets is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingpercentilenumbuckets
	RollingPercentileNumBuckets int
	// RollingPercentileBucketSize is https://github.com/Netflix/Hystrix/wiki/Configuration#metricsrollingpercentilebucketsize
	RollingPercentileBucketSize int
}

RunStatsConfig configures a RunStats

func (*RunStatsConfig) Merge

func (r *RunStatsConfig) Merge(other RunStatsConfig)

Merge this config with another

type StatFactory

type StatFactory struct {
	RunConfig      RunStatsConfig
	FallbackConfig FallbackStatsConfig
	// contains filtered or unexported fields
}

StatFactory helps the process of making stat collectors for circuit breakers

func (*StatFactory) CreateConfig

func (s *StatFactory) CreateConfig(circuitName string) circuit.Config

CreateConfig is a config factory that associates stat collection with the circuit

func (*StatFactory) FallbackStats

func (s *StatFactory) FallbackStats(circuitName string) *FallbackStats

FallbackStats returns the fallback stats for a circuit, or nil if there is none

func (*StatFactory) RunStats

func (s *StatFactory) RunStats(circuitName string) *RunStats

RunStats returns the run stats for a circuit, or nil if there is none