backoff

README

backoff

License

Pouch is licensed under the MIT License. See LICENSE for the full license text.

Documentation

Index

• type Constant
  • func (c *Constant) BackOff(retries uint) time.Duration
• type Exponential
  • func (e *Exponential) BackOff(retries uint) time.Duration
• type Jitter
  • func (j *Jitter) BackOff(retries uint) time.Duration
• type Linear
  • func (l *Linear) BackOff(retries uint) time.Duration
• type RandFloat64
• type Strategy
• type Superposition
  • func (s *Superposition) BackOff(retries uint) time.Duration

Types

type Constant

type Constant struct {
	// Delay is the amount of time to backoff after.
	Delay time.Duration
}

Constant implements the defined constant compensation algorithm.

func (*Constant) BackOff

func (c *Constant) BackOff(retries uint) time.Duration

BackOff returns the amount of time to wait before the next retry given the number of retries.

type Exponential

type Exponential struct {
	// BaseDelay is the amount of time to backoff after the first failure.
	BaseDelay time.Duration
	// Multiplier is the factor that exponentially multiplies the backoff after a retry failure.
	Multiplier float64
	// MaxDelay is the upper bound of backoff delay.
	MaxDelay time.Duration
}

Exponential implements the defined exponential compensation algorithm.

func (*Exponential) BackOff

func (e *Exponential) BackOff(retries uint) time.Duration

BackOff returns the amount of time to wait before the next retry given the number of retries.

type Jitter

type Jitter struct {
	// Jitter is the randomized backoff of jitter
	Jitter time.Duration
	// Rand is make random numbers for jitter
	Rand RandFloat64
}

Jitter implements the randomize backoff delays so that if a cluster of requests start at the same time, they won't operate in lockstep.

func (*Jitter) BackOff

func (j *Jitter) BackOff(retries uint) time.Duration

BackOff returns the amount of time to wait before the next retry given the number of retries.

type Linear

type Linear struct {
	// BaseDelay is the amount of time to backoff after.
	BaseDelay time.Duration
	// Multiplier is the factor with which to multiply backoffs after a failed retry.
	Multiplier float64
	// MaxDelay is the upper bound of backoff delay.
	MaxDelay time.Duration
}

Linear implements the defined linear compensation algorithm.

func (*Linear) BackOff

func (l *Linear) BackOff(retries uint) time.Duration

BackOff returns the amount of time to wait before the next retry given the number of retries.

type RandFloat64

type RandFloat64 interface {
	// Float64 returns, as a float64, a pseudo-random number in [0.0,1.0).
	Float64() float64
}

RandFloat64 defines the methodology for jitter.

type Strategy

type Strategy interface {
	// BackOff returns the amount of time to wait before the next retry given the number of consecutive failures.
	BackOff(retries uint) time.Duration
}

Strategy defines the methodology for backing off after.

var DefaultConstant Strategy = &Superposition{
	defaultJitter,
	&Constant{
		Delay: 1 * time.Second,
	},
}

var DefaultExponential Strategy = &Superposition{
	defaultJitter,
	&Exponential{
		BaseDelay:  1 * time.Second,
		Multiplier: 1.6,
		MaxDelay:   120 * time.Second,
	},
}

var DefaultLinear Strategy = &Superposition{
	defaultJitter,
	&Linear{
		BaseDelay:  1 * time.Second,
		Multiplier: 2,
		MaxDelay:   120 * time.Second,
	},
}

type Superposition

type Superposition []Strategy

func (*Superposition) BackOff

func (s *Superposition) BackOff(retries uint) time.Duration

BackOff returns the amount of time to wait before the next retry given the number of retries.