go.uber.org/yarpc@v1.72.1/yarpcconfig/backoff.go (about)

     1  // Copyright (c) 2022 Uber Technologies, Inc.
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    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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    19  // THE SOFTWARE.
    20  
    21  package yarpcconfig
    22  
    23  import (
    24  	"time"
    25  
    26  	backoffapi "go.uber.org/yarpc/api/backoff"
    27  	"go.uber.org/yarpc/internal/backoff"
    28  )
    29  
    30  // Backoff specifies a backoff strategy, particularly for retries.
    31  // The only supported strategy at time of writing is "exponential" with full
    32  // jitter. This structure may be extended in the future to support registering
    33  // alternate backoff strategies.
    34  //
    35  //  exponential:
    36  //    first: 100ms
    37  //    max: 30s
    38  type Backoff struct {
    39  	Exponential ExponentialBackoff `config:"exponential"`
    40  }
    41  
    42  // Strategy returns a backoff strategy constructor (in terms of the number of
    43  // attempts already made) and the given configuration, or an error.
    44  func (c Backoff) Strategy() (backoffapi.Strategy, error) {
    45  	return c.Exponential.Strategy()
    46  }
    47  
    48  // ExponentialBackoff details the exponential with full jitter backoff
    49  // strategy.
    50  // "first" defines the range of possible durations for the first attempt.
    51  // Each subsequent attempt has twice the range of possible jittered delay
    52  // duration.
    53  // The range of possible values will not exceed "max", inclusive.
    54  //
    55  //   first: 100ms
    56  //   max: 30s
    57  type ExponentialBackoff struct {
    58  	First time.Duration `config:"first"`
    59  	Max   time.Duration `config:"max"`
    60  }
    61  
    62  // Strategy returns an exponential backoff strategy (in terms of the number of
    63  // attempts already made) and the given configuration.
    64  func (c ExponentialBackoff) Strategy() (backoffapi.Strategy, error) {
    65  	var opts []backoff.ExponentialOption
    66  
    67  	if c.First > 0 {
    68  		opts = append(opts, backoff.FirstBackoff(c.First))
    69  	}
    70  	if c.Max > 0 {
    71  		opts = append(opts, backoff.MaxBackoff(c.Max))
    72  	}
    73  
    74  	return backoff.NewExponential(opts...)
    75  }