locator

Documentation

Index

• Constants
• func RegisterLocator(builder Builder)
• type Builder
• type StaticLocator
  • func NewStaticLocator(groupName string, nodes []*config.NodeWeight) *StaticLocator
  • func NewStaticLocatorFromStr(groupName string, nodes []string) (*StaticLocator, error)
  • func (s *StaticLocator) All() []*SupernodeGroup
  • func (s *StaticLocator) Get() *Supernode
  • func (s *StaticLocator) GetGroup(name string) *SupernodeGroup
  • func (s *StaticLocator) Next() *Supernode
  • func (s *StaticLocator) Refresh() bool
  • func (s *StaticLocator) Report(node string, metrics *SupernodeMetrics)
  • func (s *StaticLocator) Select(key interface{}) *Supernode
  • func (s *StaticLocator) Size() int
  • func (s *StaticLocator) String() string
• type SuperNodeEvent
  • func NewDisableEvent(node string) *SuperNodeEvent
  • func NewEnableEvent(node string) *SuperNodeEvent
• type Supernode
  • func (s *Supernode) String() string
• type SupernodeGroup
  • func (sg *SupernodeGroup) GetNode(idx int) *Supernode
• type SupernodeLocator
  • func CreateLocator(cfg *config.Config) SupernodeLocator
  • func NewHashCirclerLocator(groupName string, nodes []string, eventQueue queue.Queue) (SupernodeLocator, error)
• type SupernodeMetrics

Constants

const (
	// GroupDefaultName indicates all the supernodes in this group are set as
	// default value. It's only used when the supernode list from configuration
	// or CLI is empty.
	GroupDefaultName = "default"

	// GroupConfigName indicates all the supernodes in this group come from
	// configuration or CLI.
	GroupConfigName = "config"
)

Functions

func RegisterLocator

func RegisterLocator(builder Builder)

RegisterLocator provides a way for users to customize SupernodeLocator. This function should be invoked before CreateLocator.

Types

type Builder

type Builder func(cfg *config.Config) SupernodeLocator

Builder defines the constructor of SupernodeLocator.

var DefaultBuilder Builder = func(cfg *config.Config) SupernodeLocator {
	if cfg == nil || len(cfg.Nodes) == 0 {
		return NewStaticLocator(GroupDefaultName, config.GetDefaultSupernodesValue())
	}
	locator, _ := NewStaticLocatorFromStr(GroupConfigName, cfg.Nodes)
	return locator
}

DefaultBuilder returns a supernode locator with default value when supernodes in the config file is empty.

type StaticLocator

type StaticLocator struct {
	Group *SupernodeGroup
	// contains filtered or unexported fields
}

StaticLocator uses the nodes passed from configuration or CLI.

func NewStaticLocator

func NewStaticLocator(groupName string, nodes []*config.NodeWeight) *StaticLocator

NewStaticLocator constructs StaticLocator which uses the nodes passed from configuration or CLI.

func NewStaticLocatorFromStr

func NewStaticLocatorFromStr(groupName string, nodes []string) (*StaticLocator, error)

NewStaticLocatorFromStr constructs StaticLocator from string list. The format of nodes is: ip:port=weight

func (*StaticLocator) All

func (s *StaticLocator) All() []*SupernodeGroup

All returns all the supernodes.

func (*StaticLocator) Get

func (s *StaticLocator) Get() *Supernode

Get returns the current selected supernode, it should be idempotent. It should return nil before first calling the Next method.

func (*StaticLocator) GetGroup

func (s *StaticLocator) GetGroup(name string) *SupernodeGroup

GetGroup returns the group with the giving name.

func (*StaticLocator) Next

func (s *StaticLocator) Next() *Supernode

Next chooses the next available supernode for retrying or other purpose. The current supernode should be set as this result.

func (*StaticLocator) Refresh

func (s *StaticLocator) Refresh() bool

Refresh refreshes all the supernodes.

func (*StaticLocator) Report

func (s *StaticLocator) Report(node string, metrics *SupernodeMetrics)

Report records the metrics of the current supernode in order to choose a more appropriate supernode for the next time if necessary.

func (*StaticLocator) Select

func (s *StaticLocator) Select(key interface{}) *Supernode

Select chooses a supernode based on the giving key. It should not affect the result of method 'Get()'.

func (*StaticLocator) Size

func (s *StaticLocator) Size() int

Size returns the number of all supernodes.

func (*StaticLocator) String

func (s *StaticLocator) String() string

type SuperNodeEvent

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

func NewDisableEvent

func NewDisableEvent(node string) *SuperNodeEvent

func NewEnableEvent

func NewEnableEvent(node string) *SuperNodeEvent

type Supernode

type Supernode struct {
	Schema    string
	IP        string
	Port      int
	Weight    int
	GroupName string
	Metrics   *SupernodeMetrics
}

Supernode holds the basic information of supernodes.

func (*Supernode) String

func (s *Supernode) String() string

type SupernodeGroup

type SupernodeGroup struct {
	Name  string
	Nodes []*Supernode

	// Infos stores other information that user can customized.
	Infos map[string]string
}

SupernodeGroup groups supernodes which have same attributes. For example, we can group supernodes by region, business, version and so on. The implementation of SupernodeLocator can select a supernode based on the group.

func (*SupernodeGroup) GetNode

func (sg *SupernodeGroup) GetNode(idx int) *Supernode

GetNode return the node with the giving index.

type SupernodeLocator

type SupernodeLocator interface {
	// Get returns the current selected supernode, it should be idempotent.
	// It should return nil before first calling the Next method.
	Get() *Supernode

	// Next chooses the next available supernode for retrying or other
	// purpose. The current supernode should be set as this result.
	Next() *Supernode

	// Select chooses a supernode based on the giving key.
	// It should not affect the result of method 'Get()'.
	Select(key interface{}) *Supernode

	// GetGroup returns the group with the giving name.
	GetGroup(name string) *SupernodeGroup

	// All returns all the supernodes.
	All() []*SupernodeGroup

	// Size returns the number of all supernodes.
	Size() int

	// Report records the metrics of the current supernode in order to choose a
	// more appropriate supernode for the next time if necessary.
	Report(node string, metrics *SupernodeMetrics)

	// Refresh refreshes all the supernodes.
	Refresh() bool
}

SupernodeLocator defines the way how to get available supernodes. Developers can implement their own locator more flexibly , not just get the supernode list from configuration or CLI.

func CreateLocator

func CreateLocator(cfg *config.Config) SupernodeLocator

CreateLocator creates a supernode locator with the giving config.

func NewHashCirclerLocator

func NewHashCirclerLocator(groupName string, nodes []string, eventQueue queue.Queue) (SupernodeLocator, error)

type SupernodeMetrics

type SupernodeMetrics struct {
	Metrics map[string]interface{}
}

SupernodeMetrics holds metrics used for the locator to choose supernode.