base

Documentation

Overview

Package base defines a balancer base that can be used to build balancers with different picking algorithms.

The base balancer creates a new SubConn for each resolved address. The provided picker will only be notified about READY SubConns.

This package is the base of round_robin balancer, its purpose is to be used to build round_robin like balancers with complex picking algorithms. Balancers with more complicated logic should try to implement a balancer builder from scratch.

All APIs in this package are experimental.

Index

• func NewBalancerBuilder(name string, pb PickerBuilder) balancer.Builder
• func NewBalancerBuilderV2(name string, pb V2PickerBuilder, config Config) balancer.Builder
• func NewBalancerBuilderWithConfig(name string, pb PickerBuilder, config Config) balancer.Builder
• func NewErrPicker(err error) balancer.Picker
• func NewErrPickerV2(err error) balancer.V2Picker
• type Config
• type PickerBuildInfo
• type PickerBuilder
• type SubConnInfo
• type V2PickerBuilder

Functions

func NewBalancerBuilder

func NewBalancerBuilder(name string, pb PickerBuilder) balancer.Builder

NewBalancerBuilder returns a balancer builder. The balancers built by this builder will use the picker builder to build pickers.

func NewBalancerBuilderV2

func NewBalancerBuilderV2(name string, pb V2PickerBuilder, config Config) balancer.Builder

NewBalancerBuilderV2 returns a base balancer builder configured by the provided config.

func NewBalancerBuilderWithConfig

func NewBalancerBuilderWithConfig(name string, pb PickerBuilder, config Config) balancer.Builder

NewBalancerBuilderWithConfig returns a base balancer builder configured by the provided config.

func NewErrPicker

func NewErrPicker(err error) balancer.Picker

NewErrPicker returns a picker that always returns err on Pick().

func NewErrPickerV2

func NewErrPickerV2(err error) balancer.V2Picker

NewErrPickerV2 returns a V2Picker that always returns err on Pick().

Types

type Config

type Config struct {
	// HealthCheck indicates whether health checking should be enabled for this specific balancer.
	HealthCheck bool
}

Config contains the config info about the base balancer builder.

type PickerBuildInfo

type PickerBuildInfo struct {
	// ReadySCs is a map from all ready SubConns to the Addresses used to
	// create them.
	ReadySCs map[balancer.SubConn]SubConnInfo
}

PickerBuildInfo contains information needed by the picker builder to construct a picker.

type PickerBuilder

type PickerBuilder interface {
	// Build takes a slice of ready SubConns, and returns a picker that will be
	// used by gRPC to pick a SubConn.
	Build(readySCs map[resolver.Address]balancer.SubConn) balancer.Picker
}

PickerBuilder creates balancer.Picker.

type SubConnInfo

type SubConnInfo struct {
	Address resolver.Address // the address used to create this SubConn
}

SubConnInfo contains information about a SubConn created by the base balancer.

type V2PickerBuilder

type V2PickerBuilder interface {
	// Build returns a picker that will be used by gRPC to pick a SubConn.
	Build(info PickerBuildInfo) balancer.V2Picker
}

V2PickerBuilder creates balancer.V2Picker.