cluster

Documentation

Overview

This file implements a cluster state machine. It relies on a cluster wide key-value store for coordinating the state of the cluster. It also stores the state of the cluster in this key-value store.

Index

• func Start() error
• type Cluster
• type ClusterListener
• type ClusterManager
  • func Inst() (*ClusterManager, error)
  • func New(cfg Config, kv kvdb.Kvdb) (*ClusterManager, error)
  • func (c *ClusterManager) AddEventListener(listener ClusterListener) error
  • func (c *ClusterManager) Enumerate() (api.Cluster, error)
  • func (c *ClusterManager) Init() error
  • func (c *ClusterManager) LocateNode(nodeID string) (api.Node, error)
  • func (c *ClusterManager) Remove(nodes []api.Node) error
  • func (c *ClusterManager) Shutdown(cluster bool, nodes []api.Node) error
  • func (c *ClusterManager) Start() error
• type Config
• type Database
• type NodeEntry

Functions

func Start

func Start() error

Start will run the cluster manager daemon.

Types

type Cluster

type Cluster interface {
	// LocateNode find the node given a UUID.
	LocateNode(string) (api.Node, error)

	// AddEventListener adds an event listener and exposes cluster events.
	AddEventListener(ClusterListener) error

	// Enumerate lists all the nodes in the cluster.
	Enumerate() (api.Cluster, error)

	// Remove node(s) from the cluster permanently.
	Remove(nodes []api.Node) error

	// Shutdown node(s) or the entire cluster.
	Shutdown(cluster bool, nodes []api.Node) error

	// Start starts the cluster manager and state machine.
	// It also causes this node to join the cluster.
	Start() error
}

Cluster is the API that a cluster provider will implement.

type ClusterListener

type ClusterListener interface {
	// String returns a string representation of this listener.
	String() string

	// ClusterInit is called when a brand new cluster is initialized.
	ClusterInit(self *api.Node, db *Database) error

	// Init is called when this node is joining an existing cluster for the first time.
	Init(self *api.Node, db *Database) error

	// Join is called when this node is joining an existing cluster.
	Join(self *api.Node, db *Database) error

	// Add is called when a new node joins the cluster.
	Add(node *api.Node) error

	// Remove is called when a node leaves the cluster
	Remove(node *api.Node) error

	// Update is called when a node status changes significantly
	// in the cluster changes.
	Update(node *api.Node) error

	// Leave is called when this node leaves the cluster.
	Leave(node *api.Node) error
}

ClusterListener is an interface to be implemented by a storage driver if it is participating in a multi host environment. It exposes events in the cluster state machine. Your driver can do the needful when these events are provided.

type ClusterManager

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

func Inst

func Inst() (*ClusterManager, error)

Inst returns an instance of an already instantiated cluster manager.

func New

func New(cfg Config, kv kvdb.Kvdb) (*ClusterManager, error)

New instantiates and starts a new cluster manager.

func (*ClusterManager) AddEventListener

func (c *ClusterManager) AddEventListener(listener ClusterListener) error

func (*ClusterManager) Enumerate

func (c *ClusterManager) Enumerate() (api.Cluster, error)

func (*ClusterManager) Init

func (c *ClusterManager) Init() error

func (*ClusterManager) LocateNode

func (c *ClusterManager) LocateNode(nodeID string) (api.Node, error)

func (*ClusterManager) Remove

func (c *ClusterManager) Remove(nodes []api.Node) error

func (*ClusterManager) Shutdown

func (c *ClusterManager) Shutdown(cluster bool, nodes []api.Node) error

func (*ClusterManager) Start

func (c *ClusterManager) Start() error

type Config

type Config struct {
	ClusterId string
	NodeId    string
}

type Database

type Database struct {
	Status      api.Status
	Id          string
	NodeEntries map[string]NodeEntry
}

type NodeEntry

type NodeEntry struct {
	Id string
	Ip string
}

NodeEntry is used to discover other nodes in the cluster and setup the gossip protocol with them.