Documentation
¶
Overview ¶
Package retrier allow to retry execute a function in case of errors.
Index ¶
Examples ¶
Constants ¶
const ( // DefaultAttempts is the default maximum number of retry attempts. DefaultAttempts = 4 // DefaultDelay is the default delay to apply after the first failed attempt. DefaultDelay = 1 * time.Second // DefaultDelayFactor is the default multiplication factor to get the successive delay value. DefaultDelayFactor = 2 // DefaultJitter is the default maximum random Jitter time between retries. DefaultJitter = 1 * time.Millisecond // DefaultTimeout is the default timeout applied to each function call via context. DefaultTimeout = 1 * time.Second )
Variables ¶
This section is empty.
Functions ¶
func DefaultRetryIf ¶
DefaultRetryIf is the default function to check the retry condition.
Types ¶
type Option ¶
Option is the interface that allows to set the options.
func WithAttempts ¶
WithAttempts set the maximum number of retries.
func WithDelayFactor ¶
WithDelayFactor set the multiplication factor to get the successive delay value. A delay factor greater than 1 means an exponential delay increase. if the delay factor is 2 and the first delay is 1, then the delays will be: [1, 2, 4, 8, ...].
func WithJitter ¶
WithJitter sets the maximum random Jitter time between retries. This is useful to avoid the Thundering herd problem (https://en.wikipedia.org/wiki/Thundering_herd_problem).
func WithRetryIfFn ¶
WithRetryIfFn set the function used to decide when retry.
func WithTimeout ¶
WithTimeout sets the timeout applied to each function call via context.
type Retrier ¶
type Retrier struct {
// contains filtered or unexported fields
}
Retrier represents an instance of the HTTP retrier.
func (*Retrier) Run ¶
Run attempts to execute the task according to the retry rules.
Example ¶
package main
import (
"context"
"fmt"
"log"
"time"
"github.com/Vonage/gosrvlib/pkg/retrier"
)
func main() {
var count int
// example function that returns nil only at the third attempt.
task := func(_ context.Context) error {
if count == 2 {
return nil
}
count++
return fmt.Errorf("ERROR")
}
opts := []retrier.Option{
retrier.WithRetryIfFn(retrier.DefaultRetryIf),
retrier.WithAttempts(5),
retrier.WithDelay(10 * time.Millisecond),
retrier.WithDelayFactor(1.1),
retrier.WithJitter(5 * time.Millisecond),
retrier.WithTimeout(2 * time.Millisecond),
}
r, err := retrier.New(opts...)
if err != nil {
log.Fatal(err)
}
timeout := 1 * time.Second
ctx, cancel := context.WithTimeout(context.TODO(), timeout)
err = r.Run(ctx, task)
cancel()
if err != nil {
log.Fatal(err)
}
fmt.Println(count)
}
Output: 2
Source Files