sd

Documentation

Overview

Package sd defines some interfaces and implementations for service discovery

Index

• Variables
• type Balancer
  • func NewRandomLB(subscriber Subscriber, seed int64) Balancer
  • func NewRoundRobinLB(subscriber Subscriber) Balancer
• type FixedSubscriber
  • func (s FixedSubscriber) Hosts() ([]string, error)
• type Subscriber
  • func FixedSubscriberFactory(cfg *config.Backend) Subscriber
• type SubscriberFactory

Variables

var ErrNoHosts = errors.New("no hosts available")

ErrNoHosts is the error the balancer must return when there are 0 hosts ready

Types

type Balancer

type Balancer interface {
	Host() (string, error)
}

Balancer applys a balancing stategy in order to select the backend host to be used

func NewRandomLB

func NewRandomLB(subscriber Subscriber, seed int64) Balancer

NewRandomLB returns a new balancer using a pseudo-random strategy

func NewRoundRobinLB

func NewRoundRobinLB(subscriber Subscriber) Balancer

NewRoundRobinLB returns a new balancer using a round robin strategy

type FixedSubscriber

type FixedSubscriber []string

FixedSubscriber has a constant set of backend hosts and they never get updated

func (FixedSubscriber) Hosts

func (s FixedSubscriber) Hosts() ([]string, error)

Hosts implements the subscriber interface

type Subscriber

type Subscriber interface {
	Hosts() ([]string, error)
}

Subscriber keeps the set of backend hosts up to date

func FixedSubscriberFactory

func FixedSubscriberFactory(cfg *config.Backend) Subscriber

FixedSubscriberFactory builds a FixedSubscriber with the received config

type SubscriberFactory

type SubscriberFactory func(*config.Backend) Subscriber

SubscriberFactory builds subscribers with the received config