cluster

Documentation

Overview

Package cluster provides an elastic peer discovery and gossip layer.

Ingest and store instances join the same cluster and know about each other. Store instances consume segments from each ingest instance, and broadcast queries to each store instance. In the future, ingest instances will share load information to potentially refuse connections and balance writes.

Index

• Constants
• func CalculateAdvertiseIP(bindHost, advertiseHost string, resolver Resolver, logger log.Logger) (net.IP, error)
• type Peer
  • func NewPeer(bindAddr string, bindPort int, advertiseAddr string, advertisePort int, ...) (*Peer, error)
  • func (p *Peer) ClusterSize() int
  • func (p *Peer) Current(t PeerType) []string
  • func (p *Peer) Leave(timeout time.Duration) error
  • func (p *Peer) Name() string
  • func (p *Peer) State() map[string]interface{}
• type PeerType
• type Resolver

Constants

const (
	// PeerTypeIngest serves the ingest API.
	PeerTypeIngest PeerType = "ingest"

	// PeerTypeStore serves the store API.
	PeerTypeStore = "store"

	// PeerTypeIngestStore serves both ingest and store APIs.
	PeerTypeIngestStore = "ingeststore"
)

Functions

func CalculateAdvertiseIP

func CalculateAdvertiseIP(bindHost, advertiseHost string, resolver Resolver, logger log.Logger) (net.IP, error)

CalculateAdvertiseIP deduces the best IP on which to advertise our API based on a user-provided bind host and advertise host. This code lifts some logic out of the memberlist internals, and augments it with extra logic to resolve hostnames. (Memberlist demands pure IPs.)

Types

type Peer

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

Peer represents this node in the cluster.

func NewPeer

func NewPeer(
	bindAddr string, bindPort int,
	advertiseAddr string, advertisePort int,
	existing []string,
	t PeerType, apiPort int,
	logger log.Logger,
) (*Peer, error)

NewPeer creates or joins a cluster with the existing peers. We will listen for cluster communications on the bind addr:port. We advertise a PeerType HTTP API, reachable on apiPort.

If advertiseAddr is not empty, we will advertise ourself as reachable for cluster communications on that address; otherwise, memberlist will extract the IP from the bound addr:port and advertise on that.

func (*Peer) ClusterSize

func (p *Peer) ClusterSize() int

ClusterSize returns the total size of the cluster from this node's perspective.

func (*Peer) Current

func (p *Peer) Current(t PeerType) []string

Current API host:ports for the given type of node.

func (*Peer) Leave

func (p *Peer) Leave(timeout time.Duration) error

Leave the cluster, waiting up to timeout.

func (*Peer) Name

func (p *Peer) Name() string

Name returns the unique ID of this peer in the cluster.

func (*Peer) State

func (p *Peer) State() map[string]interface{}

State returns a JSON-serializable dump of cluster state. Useful for debug.

type PeerType

type PeerType string

PeerType enumerates the types of nodes in the cluster.

type Resolver

type Resolver interface {
	LookupIPAddr(ctx context.Context, address string) ([]net.IPAddr, error)
}

Resolver models net.DefaultResolver.