lb

Documentation

Overview

Package lb implements the client-side load balancer pattern. When combined with a service discovery system of record, it enables a more decentralized architecture, removing the need for separate load balancers like HAProxy.

Index

• Variables
• func Retry(max int, timeout time.Duration, b Balancer) endpoint.Endpoint
• type Balancer
  • func NewRandom(s sd.Subscriber, seed int64) Balancer
  • func NewRoundRobin(s sd.Subscriber) Balancer

Variables

var ErrNoEndpoints = errors.New("no endpoints available")

ErrNoEndpoints is returned when no qualifying endpoints are available.

Functions

func Retry

func Retry(max int, timeout time.Duration, b Balancer) endpoint.Endpoint

Retry wraps a service load balancer and returns an endpoint oriented load balancer for the specified service method. Requests to the endpoint will be automatically load balanced via the load balancer. Requests that return errors will be retried until they succeed, up to max times, or until the timeout is elapsed, whichever comes first.

Types

type Balancer

type Balancer interface {
	Endpoint() (endpoint.Endpoint, error)
}

Balancer yields endpoints according to some heuristic.

func NewRandom

func NewRandom(s sd.Subscriber, seed int64) Balancer

NewRandom returns a load balancer that selects services randomly.

func NewRoundRobin

func NewRoundRobin(s sd.Subscriber) Balancer

NewRoundRobin returns a load balancer that returns services in sequence.