Documentation

Index

Constants

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const (
	// NoInterval represents Maximim interval
	NoInterval = 0

	// DefaultBackoffCoefficient is default backOffCoefficient for retryPolicy
	DefaultBackoffCoefficient = 2.0
)

Variables

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var SystemClock = systemClock{}

    SystemClock implements Clock interface that uses time.Now().

    Functions

    func IgnoreErrors

    func IgnoreErrors(errorsToExclude []error) func(error) bool

      IgnoreErrors can be used as IsRetryable handler for Retry function to exclude certain errors from the retry list

      func Retry

      func Retry(ctx context.Context, operation Operation, policy RetryPolicy, isRetryable IsRetryable) error

        Retry function can be used to wrap any call with retry logic using the passed in policy

        Types

        type Clock

        type Clock interface {
        	Now() time.Time
        }

          Clock used by ExponentialRetryPolicy implementation to get the current time. Mainly used for unit testing

          type ConcurrentRetrier

          type ConcurrentRetrier struct {
          	sync.Mutex
          	// contains filtered or unexported fields
          }

            ConcurrentRetrier is used for client-side throttling. It determines whether to throttle outgoing traffic in case downstream backend server rejects requests due to out-of-quota or server busy errors.

            func NewConcurrentRetrier

            func NewConcurrentRetrier(retryPolicy RetryPolicy) *ConcurrentRetrier

              NewConcurrentRetrier returns an instance of concurrent backoff retrier.

              func (*ConcurrentRetrier) Failed

              func (c *ConcurrentRetrier) Failed()

                Failed marks client request failed because backend is busy.

                func (*ConcurrentRetrier) Succeeded

                func (c *ConcurrentRetrier) Succeeded()

                  Succeeded marks client request succeeded.

                  func (*ConcurrentRetrier) Throttle

                  func (c *ConcurrentRetrier) Throttle()

                    Throttle Sleep if there were failures since the last success call.

                    type ExponentialRetryPolicy

                    type ExponentialRetryPolicy struct {
                    	// contains filtered or unexported fields
                    }

                      ExponentialRetryPolicy provides the implementation for retry policy using a coefficient to compute the next delay. Formula used to compute the next delay is: initialInterval * math.Pow(backoffCoefficient, currentAttempt)

                      func NewExponentialRetryPolicy

                      func NewExponentialRetryPolicy(initialInterval time.Duration) *ExponentialRetryPolicy

                        NewExponentialRetryPolicy returns an instance of ExponentialRetryPolicy using the provided initialInterval

                        func (*ExponentialRetryPolicy) ComputeNextDelay

                        func (p *ExponentialRetryPolicy) ComputeNextDelay(elapsedTime time.Duration, numAttempts int) time.Duration

                          ComputeNextDelay returns the next delay interval. This is used by Retrier to delay calling the operation again

                          func (*ExponentialRetryPolicy) SetBackoffCoefficient

                          func (p *ExponentialRetryPolicy) SetBackoffCoefficient(backoffCoefficient float64)

                            SetBackoffCoefficient sets the coefficient used by ExponentialRetryPolicy to compute next delay for each retry All retries are computed using the following formula: initialInterval * math.Pow(backoffCoefficient, currentAttempt)

                            func (*ExponentialRetryPolicy) SetExpirationInterval

                            func (p *ExponentialRetryPolicy) SetExpirationInterval(expirationInterval time.Duration)

                              SetExpirationInterval sets the absolute expiration interval for all retries

                              func (*ExponentialRetryPolicy) SetInitialInterval

                              func (p *ExponentialRetryPolicy) SetInitialInterval(initialInterval time.Duration)

                                SetInitialInterval sets the initial interval used by ExponentialRetryPolicy for the very first retry All later retries are computed using the following formula: initialInterval * math.Pow(backoffCoefficient, currentAttempt)

                                func (*ExponentialRetryPolicy) SetMaximumAttempts

                                func (p *ExponentialRetryPolicy) SetMaximumAttempts(maximumAttempts int)

                                  SetMaximumAttempts sets the maximum number of retry attempts

                                  func (*ExponentialRetryPolicy) SetMaximumInterval

                                  func (p *ExponentialRetryPolicy) SetMaximumInterval(maximumInterval time.Duration)

                                    SetMaximumInterval sets the maximum interval for each retry

                                    type IsRetryable

                                    type IsRetryable func(error) bool

                                      IsRetryable handler can be used to exclude certain errors during retry

                                      type Operation

                                      type Operation func() error

                                        Operation to retry

                                        type Retrier

                                        type Retrier interface {
                                        	NextBackOff() time.Duration
                                        	Reset()
                                        }

                                          Retrier manages the state of retry operation

                                          func NewRetrier

                                          func NewRetrier(policy RetryPolicy, clock Clock) Retrier

                                            NewRetrier is used for creating a new instance of Retrier

                                            type RetryPolicy

                                            type RetryPolicy interface {
                                            	ComputeNextDelay(elapsedTime time.Duration, numAttempts int) time.Duration
                                            }

                                              RetryPolicy is the API which needs to be implemented by various retry policy implementations