ring

Documentation

Index

• Constants
• Variables
• func GenerateTokens(numTokens int, takenTokens []uint32) []uint32
• func ProtoDescFactory() proto.Message
• type ByToken
  • func (ts ByToken) Len() int
  • func (ts ByToken) Less(i, j int) bool
  • func (ts ByToken) Swap(i, j int)
• type CASCallback
• type Codec
• type Config
  • func (cfg *Config) RegisterFlags(f *flag.FlagSet)
• type ConsulConfig
  • func (cfg *ConsulConfig) RegisterFlags(f *flag.FlagSet)
• type KVClient
  • func NewConsulClient(cfg ConsulConfig, codec Codec) (KVClient, error)
  • func NewInMemoryKVClient() KVClient
  • func PrefixClient(client KVClient, prefix string) KVClient
• type Operation
• type ProtoCodec
  • func (p ProtoCodec) Decode(bytes []byte) (interface{}, error)
  • func (p ProtoCodec) Encode(msg interface{}) ([]byte, error)
• type ReadRing
• type Ring
  • func New(cfg Config) (*Ring, error)
  • func (r *Ring) BatchGet(keys []uint32, n int, op Operation) ([][]*IngesterDesc, error)
  • func (r *Ring) Collect(ch chan<- prometheus.Metric)
  • func (r *Ring) Describe(ch chan<- *prometheus.Desc)
  • func (r *Ring) Get(key uint32, n int, op Operation) ([]*IngesterDesc, error)
  • func (r *Ring) GetAll() []*IngesterDesc
  • func (r *Ring) IsHealthy(ingester *IngesterDesc) bool
  • func (r *Ring) ServeHTTP(w http.ResponseWriter, req *http.Request)
  • func (r *Ring) Stop()

Constants

const (

	// ConsulKey is the key under which we store the ring in consul.
	ConsulKey = "ring"
)

Variables

var ErrEmptyRing = errors.New("empty circle")

ErrEmptyRing is the error returned when trying to get an element when nothing has been added to hash.

var (

	// ErrNotFound is returned by ConsulClient.Get.
	ErrNotFound = fmt.Errorf("Not found")
)

Functions

func GenerateTokens

func GenerateTokens(numTokens int, takenTokens []uint32) []uint32

GenerateTokens make numTokens random tokens, none of which clash with takenTokens. Assumes takenTokens is sorted.

func ProtoDescFactory

func ProtoDescFactory() proto.Message

ProtoDescFactory makes new Descs

Types

type ByToken

type ByToken []*TokenDesc

ByToken is a sortable list of TokenDescs

func (ByToken) Len

func (ts ByToken) Len() int

func (ByToken) Less

func (ts ByToken) Less(i, j int) bool

func (ByToken) Swap

func (ts ByToken) Swap(i, j int)

type CASCallback

type CASCallback func(in interface{}) (out interface{}, retry bool, err error)

CASCallback is the type of the callback to CAS. If err is nil, out must be non-nil.

type Codec

type Codec interface {
	Decode([]byte) (interface{}, error)
	Encode(interface{}) ([]byte, error)
}

Codec allows the consult client to serialise and deserialise values.

type Config

type Config struct {
	ConsulConfig

	HeartbeatTimeout time.Duration
	Mock             KVClient
	// contains filtered or unexported fields
}

Config for a Ring

func (*Config) RegisterFlags

func (cfg *Config) RegisterFlags(f *flag.FlagSet)

RegisterFlags adds the flags required to config this to the given FlagSet

type ConsulConfig

type ConsulConfig struct {
	Host              string
	Prefix            string
	HTTPClientTimeout time.Duration
}

ConsulConfig to create a ConsulClient

func (*ConsulConfig) RegisterFlags

func (cfg *ConsulConfig) RegisterFlags(f *flag.FlagSet)

RegisterFlags adds the flags required to config this to the given FlagSet

type KVClient

type KVClient interface {
	CAS(key string, f CASCallback) error
	WatchKey(ctx context.Context, key string, f func(interface{}) bool)
	Get(key string) (interface{}, error)
	PutBytes(key string, buf []byte) error
}

KVClient is a high-level client for Consul, that exposes operations such as CAS and Watch which take callbacks. It also deals with serialisation by having an instance factory passed in to methods and deserialising into that.

func NewConsulClient

func NewConsulClient(cfg ConsulConfig, codec Codec) (KVClient, error)

NewConsulClient returns a new ConsulClient.

func NewInMemoryKVClient

func NewInMemoryKVClient() KVClient

NewInMemoryKVClient makes a new mock consul client.

func PrefixClient

func PrefixClient(client KVClient, prefix string) KVClient

PrefixClient takes a ConsulClient and forces a prefix on all its operations.

type Operation

type Operation int

Operation can be Read or Write

const (
	Read Operation = iota
	Write
)

Values for Operation

type ProtoCodec

type ProtoCodec struct {
	Factory func() proto.Message
}

ProtoCodec is a Codec for proto/snappy

func (ProtoCodec) Decode

func (p ProtoCodec) Decode(bytes []byte) (interface{}, error)

Decode implements Codec

func (ProtoCodec) Encode

func (p ProtoCodec) Encode(msg interface{}) ([]byte, error)

Encode implements Codec

type ReadRing

type ReadRing interface {
	prometheus.Collector

	Get(key uint32, n int, op Operation) ([]*IngesterDesc, error)
	BatchGet(keys []uint32, n int, op Operation) ([][]*IngesterDesc, error)
	GetAll() []*IngesterDesc
	IsHealthy(*IngesterDesc) bool
}

ReadRing represents the read inferface to the ring.

type Ring

type Ring struct {
	KVClient KVClient
	// contains filtered or unexported fields
}

Ring holds the information about the members of the consistent hash circle.

func New

func New(cfg Config) (*Ring, error)

New creates a new Ring

func (*Ring) BatchGet

func (r *Ring) BatchGet(keys []uint32, n int, op Operation) ([][]*IngesterDesc, error)

BatchGet returns n (or more) ingesters which form the replicas for the given key. The order of the result matches the order of the input.

func (*Ring) Collect

func (r *Ring) Collect(ch chan<- prometheus.Metric)

Collect implements prometheus.Collector.

func (*Ring) Describe

func (r *Ring) Describe(ch chan<- *prometheus.Desc)

Describe implements prometheus.Collector.

func (*Ring) Get

func (r *Ring) Get(key uint32, n int, op Operation) ([]*IngesterDesc, error)

Get returns n (or more) ingesters which form the replicas for the given key.

func (*Ring) GetAll

func (r *Ring) GetAll() []*IngesterDesc

GetAll returns all available ingesters in the circle.

func (*Ring) IsHealthy

func (r *Ring) IsHealthy(ingester *IngesterDesc) bool

IsHealthy checks whether an ingester appears to be alive and heartbeating

func (*Ring) ServeHTTP

func (r *Ring) ServeHTTP(w http.ResponseWriter, req *http.Request)

func (*Ring) Stop

func (r *Ring) Stop()

Stop the distributor.