tiflash

Documentation

Index

• Constants
• func GetTiFlashReplicaRead(policy ReplicaRead) string
• type ReplicaRead
  • func GetTiFlashReplicaReadByStr(str string) ReplicaRead
  • func (policy ReplicaRead) IsAllReplicas() bool
  • func (policy ReplicaRead) IsClosestReplicas() bool

Constants

const (
	// AllReplicaStr is the string value of AllReplicas.
	AllReplicaStr = "all_replicas"
	// ClosestAdaptiveStr is the string value of ClosestAdaptive.
	ClosestAdaptiveStr = "closest_adaptive"
	// ClosestReplicasStr is the string value of ClosestReplicas.
	ClosestReplicasStr = "closest_replicas"
)

const (
	// MaxRemoteReadCountPerNodeForClosestReplicas is the max remote read count per node for "closest_replicas".
	MaxRemoteReadCountPerNodeForClosestReplicas = 3
)

Functions

func GetTiFlashReplicaRead

func GetTiFlashReplicaRead(policy ReplicaRead) string

GetTiFlashReplicaRead return corresponding policy string in integer.

Types

type ReplicaRead

type ReplicaRead int

ReplicaRead is the policy to select TiFlash nodes.

const (
	// AllReplicas  means using all the available nodes to do analytic computing, regardless of local zone or other zones.
	AllReplicas ReplicaRead = iota
	// ClosestAdaptive means using the nodes in the same zone as the entry TiDB. If not all the tiflash data can be accessed, the query will involve the tiflash nodes from other zones.
	ClosestAdaptive
	// ClosestReplicas means using only the nodes in the same zone as the entry TiDB. If not all the tiflash data can be accessed, the query will report an error, and show an error message. Because of the feature of TiFlash remote read, a small number of regions  in other zones is acceptable, but performance will be affected. The threshold is fixed, 3 regions per tiflash node.
	ClosestReplicas
)

func GetTiFlashReplicaReadByStr

func GetTiFlashReplicaReadByStr(str string) ReplicaRead

GetTiFlashReplicaReadByStr return corresponding policy in string.

func (ReplicaRead) IsAllReplicas

func (policy ReplicaRead) IsAllReplicas() bool

IsAllReplicas return whether the policy is AllReplicas.

func (ReplicaRead) IsClosestReplicas

func (policy ReplicaRead) IsClosestReplicas() bool

IsClosestReplicas return whether the policy is ClosestReplicas.