exponential_backoff

Documentation

Index

• Constants
• Variables
• func CalculateDelay(initialDelay time.Duration, retryCount int) time.Duration
• func CalculateDelayWithMax(initialDelay time.Duration, maxDelay time.Duration, retryCount int) time.Duration

Constants

const (
	MaxExponentialBackoffDelay         = 32 * time.Second
	ExponentialDelayFactor     float64 = 2.0  // Each delta delay is twice bigger.
	ExponentialDelayRandomMs           = 1000 // Each delay has random additional milliseconds.
)

Variables

var ExponentialCalculationsCount = int(math.Log(MaxExponentialBackoffDelay.Seconds()) / math.Log(ExponentialDelayFactor))

ExponentialCalculationsCount counts of exponential calculations before return max delay to prevent overflow with big numbers.

Functions

func CalculateDelay

func CalculateDelay(initialDelay time.Duration, retryCount int) time.Duration

CalculateDelay returns delay distributed from initialDelay to default maxDelay (32s)

Example:

Retry 0: 5s
Retry 1: 6s
Retry 2: 7.8s
Retry 3: 9.8s
Retry 4: 13s
Retry 5: 21s
Retry 6: 32s
Retry 7: 32s

func CalculateDelayWithMax

func CalculateDelayWithMax(initialDelay time.Duration, maxDelay time.Duration, retryCount int) time.Duration

CalculateDelayWithMax returns delay distributed from initialDelay to maxDelay based on retryCount number.

Delay for retry number 0 is an initialDelay.

Calculation of exponential delays starts from retry number 1.

After ExponentialCalculationsCount rounds of calculations, maxDelay is returned.