balancer

Documentation

Overview

Package balancer provides a simple interface to create concrete balancer algorightms that can be used to choose an upstream

Index

• Variables
• type Balancer
  • func New(balance string) (Balancer, error)
• type RoundrobinBalancer
  • func NewRoundrobinBalancer() *RoundrobinBalancer
  • func (b *RoundrobinBalancer) Elect(hosts []*Target) (*Target, error)
• type Target
• type WeightBalancer
  • func NewWeightBalancer() *WeightBalancer
  • func (b *WeightBalancer) Elect(hosts []*Target) (*Target, error)

Variables

var (
	// ErrEmptyBackendList is used when the list of beckends is empty
	ErrEmptyBackendList = errors.New("can not elect backend, Backends empty")
	// ErrCannotElectBackend is used a backend cannot be elected
	ErrCannotElectBackend = errors.New("cant elect backend")
	// ErrUnsupportedAlgorithm is used when an unsupported algorithm is given
	ErrUnsupportedAlgorithm = errors.New("unsupported balancing algorithm")
)

var (
	// ErrZeroWeight is used when there a zero value weight was given
	ErrZeroWeight = errors.New("invalid backend, weight 0 given")
)

Types

type Balancer

type Balancer interface {
	Elect(hosts []*Target) (*Target, error)
}

Balancer holds the load balancer methods for many different algorithms

func New

func New(balance string) (Balancer, error)

New creates a new Balancer based on balancing strategy

type RoundrobinBalancer

type RoundrobinBalancer struct {
	// contains filtered or unexported fields
}

RoundrobinBalancer balancer

func NewRoundrobinBalancer

func NewRoundrobinBalancer() *RoundrobinBalancer

NewRoundrobinBalancer creates a new instance of Roundrobin

func (*RoundrobinBalancer) Elect

func (b *RoundrobinBalancer) Elect(hosts []*Target) (*Target, error)

Elect backend using roundrobin strategy

type Target

type Target struct {
	Target string
	Weight int
}

Target is an ip address/hostname with a port that identifies an instance of a backend service

type WeightBalancer

type WeightBalancer struct{}

WeightBalancer balancer

func NewWeightBalancer

func NewWeightBalancer() *WeightBalancer

NewWeightBalancer creates a new instance of WeightBalancer

func (*WeightBalancer) Elect

func (b *WeightBalancer) Elect(hosts []*Target) (*Target, error)

Elect backend using weight strategy