retry

README

♻️ retry

The most advanced interruptible mechanism to perform actions repetitively until successful.

💡 Idea

The retry based on Rican7/retry but fully reworked and focused on integration with the 🚧 breaker and the built-in context package.

ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()

action := func(ctx context.Context) (err error) {
	req := req.Clone(ctx)
	resp, err = http.DefaultClient.Do(req)
	return err
}

how := []retry.How{
	strategy.Limit(5),
	strategy.BackoffWithJitter(
		backoff.Fibonacci(10*time.Millisecond),
		jitter.NormalDistribution(
			rand.New(rand.NewSource(time.Now().UnixNano())),
			0.25,
		),
	),
}

if err := retry.Do(ctx, action, how...); err != nil {
	log.Fatal(err)
}

A full description of the idea is available here.

🏆 Motivation

I developed distributed systems at Lazada, and later at Avito, which communicate with each other through a network, and I need a package to make these communications more reliable.

🤼‍♂️ How to

rewriting...

🧩 Integration

The library uses SemVer for versioning, and it is not BC-safe through major releases. You can use go modules to manage its version.

$ go get github.com/kamilsk/retry/v5@latest

🤲 Outcomes

Console tool to execute commands until successful

...

See more details here.

made with ❤️ for everyone

Documentation

Overview

Package retry provides the most advanced interruptible mechanism to perform actions repetitively until successful.

The retry based on https://github.com/Rican7/retry but fully reworked and focused on integration with the https://github.com/kamilsk/breaker and the built-in https://pkg.go.dev/context package.

Index

• func Do(breaker Breaker, action func(context.Context) error, ...) error
• func Go(breaker Breaker, action func(context.Context) error, ...) error
• type Action
• type Breaker
• type Error
  • func (err Error) Error() string
  • func (err Error) Unwrap() error
• type How

Functions

func Do

func Do(
	breaker Breaker,
	action func(context.Context) error,
	strategies ...func(Breaker, uint, error) bool,
) error

Do takes the action and performs it, repetitively, until successful.

Optionally, strategies may be passed that assess whether or not an attempt should be made.

func Go

func Go(
	breaker Breaker,
	action func(context.Context) error,
	strategies ...func(Breaker, uint, error) bool,
) error

Go takes the action and performs it, repetitively, until successful. It differs from the Do method in that it performs the action in a goroutine.

Optionally, strategies may be passed that assess whether or not an attempt should be made.

Types

type Action

type Action = func(context.Context) error

Action defines a callable function that package retry can handle.

type Breaker

type Breaker = interface {
	// Done returns a channel that's closed when a cancellation signal occurred.
	Done() <-chan struct{}
	// If Done is not yet closed, Err returns nil.
	// If Done is closed, Err returns a non-nil error.
	// After Err returns a non-nil error, successive calls to Err return the same error.
	Err() error
}

A Breaker carries a cancellation signal to interrupt an action execution.

It is a subset of the built-in context and github.com/kamilsk/breaker interfaces.

type Error

type Error string

Error defines a string-based error without a different root cause.

func (Error) Error

func (err Error) Error() string

Error returns a string representation of an error.

func (Error) Unwrap

func (err Error) Unwrap() error

Unwrap always returns nil means that an error doesn't have other root cause.

type How

type How = []func(Breaker, uint, error) bool

How is an alias for batch of Strategies.

how := retry.How{
	strategy.Limit(3),
}