Consistent Hashing Package

Description

The consistenthash package implements Consistent Hashing, a key technique in distributed systems for distributing data across a cluster in a way that minimizes reorganization when nodes are added or removed. This is particularly useful for load balancing and caching strategies.

Installation

To use the consistenthash package in your Go project, install it using the go get command:

go get github.com/starton-io/go-dispatch/consistenthash

Usage

Below is as simple example demonstrating how to use the consistenthash package to distribute data across a cluster of nodes:

import (
    "fmt"
    "github.com/starton-io/go-dispatch/consistenthash"
)

func main() {
    // Initialize the consistent hash with a specified number of replicas and an optional hash function.
    ch := consistenthash.New(consistenthash.WithReplicas(50)) // Here, 50 is the number of replicas.

    // Add nodes to the hash ring.
    ch.Add("Node1")
    ch.Add("Node2")
    ch.Add("Node3")

    // Retrieve the node responsible for a given key.
    node := ch.Get("myKey")
    fmt.Println("Node for key 'myKey':", node)

    // Retrieve the node responsible for a given key by using the least loaded node
    node, _ := ch.GetLeast("myKey")
    fmt.Println("Node for key 'myKey' by using the least loaded node:", node)

	// Use inc to increase the load of a node
    ch.Inc(node)

    // Example of removing a node from the hash ring.
    ch.Remove("Node2")

    // Retrieve the node for the same key after removing a node.
    nodeAfterRemoval := ch.Get("myKey")
    fmt.Println("Node for key 'myKey' after removal:", nodeAfterRemoval)
}

This example covers initializing the hash ring, adding nodes, finding the node for a specific key, and observing the effect of removing a node from the hash ring.