balancer

Documentation

Index

• Constants
• Variables
• func NewConsistentHashBalancerBuilder() balancer.Builder
• type ConsistentHashPicker
  • func NewConsistentHashPicker(subConns map[string]balancer.SubConn) *ConsistentHashPicker
  • func (p *ConsistentHashPicker) Pick(info balancer.PickInfo) (balancer.PickResult, error)
• type PickResult
• type Queue
  • func NewQueue() *Queue
  • func (q *Queue) DeQueue() (interface{}, bool)
  • func (q *Queue) EnQueue(value interface{})
  • func (q *Queue) IsEmpty() bool
  • func (q *Queue) Len() int

Constants

const (
	// Policy defines the name or identifier for the consistent hashing load balancing policy.
	Policy = "consistenthashpolicy"

	// Key is the context key used to retrieve the hash key for consistent hashing.
	Key = "consistenthashkey"

	// ConnectionLifetime specifies the duration for which a connection is maintained
	// before being considered for termination or renewal.
	ConnectionLifetime = time.Second * 5
)

Variables

var (
	// ErrSubConnMissing indicates that a SubConn (sub-connection) was expected but not found.
	ErrSubConnMissing = fmt.Errorf("sub-connection is missing or not found")
	// ErrSubConnResetFailure indicates an error occurred while trying to reset the SubConn.
	ErrSubConnResetFailure = fmt.Errorf("failed to reset the sub-connection")
)

Functions

func NewConsistentHashBalancerBuilder

func NewConsistentHashBalancerBuilder() balancer.Builder

NewConsistentHashBalancerBuilder returns a consistentHashBalancerBuilder.

Types

type ConsistentHashPicker

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

ConsistentHashPicker is a custom gRPC picker that uses consistent hashing to determine which backend server should handle the request.

func NewConsistentHashPicker

func NewConsistentHashPicker(subConns map[string]balancer.SubConn) *ConsistentHashPicker

NewConsistentHashPicker initializes and returns a new ConsistentHashPicker. It creates a hash ring from the provided set of backend server addresses.

func (*ConsistentHashPicker) Pick

func (p *ConsistentHashPicker) Pick(info balancer.PickInfo) (balancer.PickResult, error)

Pick selects an appropriate backend server (SubConn) for the incoming request. If a custom key is provided in the context, it will be used for consistent hashing; otherwise, the full method name of the request will be used.

type PickResult

type PickResult struct {
	Ctx context.Context
	SC  balancer.SubConn
}

PickResult represents the result of a pick operation. It contains the context and the selected SubConn for the request.

type Queue

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

Queue is a basic FIFO queue based on a doubly linked list.

func NewQueue

func NewQueue() *Queue

NewQueue returns a new queue.

func (*Queue) DeQueue

func (q *Queue) DeQueue() (interface{}, bool)

DeQueue removes and returns the first item in the queue.

func (*Queue) EnQueue

func (q *Queue) EnQueue(value interface{})

EnQueue adds an item to the end of the queue.

func (*Queue) IsEmpty

func (q *Queue) IsEmpty() bool

IsEmpty returns true if the queue is empty.

func (*Queue) Len

func (q *Queue) Len() int

Len returns the number of items in the queue.