Kyle Isom 9d1e3ab2f0 | ||
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LICENSE | ||
README.md | ||
backoff.go | ||
backoff_test.go |
README.md
backoff
Go implementation of "Exponential Backoff And Jitter"
This package implements the backoff strategy described in the AWS
Architecture Blog article
"Exponential Backoff And Jitter". Essentially,
the backoff has an interval time.Duration
; the nth call
to backoff will return an a time.Duration
that is 2 n *
interval. If jitter is enabled (which is the default behaviour), the
duration is a random value between 0 and 2 n * interval.
The backoff is configured with a maximum duration that will not be
exceeded; e.g., by default, the longest duration returned is
backoff.DefaultMaxDuration
.
Usage
A Backoff
is initialised with a call to New
. Using zero values
causes it to use DefaultMaxDuration
and DefaultInterval
as the
maximum duration and interval.
package something
import "github.com/cloudflare/backoff"
func retryable() {
b := backoff.New(0, 0)
for {
err := someOperation()
if err == nil {
break
}
log.Printf("error in someOperation: %v", err)
<-time.After(b.Duration())
}
log.Printf("succeeded after %d tries", b.Tries()+1)
b.Reset()
}
It can also be used to rate limit code that should retry infinitely, but which does not
use Backoff
itself.
package something
import (
"time"
"github.com/cloudflare/backoff"
)
func retryable() {
b := backoff.New(0, 0)
b.SetDecay(30 * time.Second)
for {
// b will reset if someOperation returns later than
// the last call to b.Duration() + 30s.
err := someOperation()
if err == nil {
break
}
log.Printf("error in someOperation: %v", err)
<-time.After(b.Duration())
}
}
Tunables
NewWithoutJitter
creates a Backoff that doesn't use jitter.
The default behaviour is controlled by two variables:
DefaultInterval
sets the base interval for backoffs created with the zerotime.Duration
value in theInterval
field.DefaultMaxDuration
sets the maximum duration for backoffs created with the zerotime.Duration
value in theMaxDuration
field.