/hashring

Consistent hashing "hashring" implementation in golang (using the same algorithm as libketama)

Primary LanguageGoMIT LicenseMIT

hashring

Implements consistent hashing that can be used when the number of server nodes can increase or decrease (like in memcached). The hashing ring is built using the same algorithm as libketama.

This is a port of Python hash_ring library https://pypi.python.org/pypi/hash_ring/ in Go with the extra methods to add and remove nodes.

Using

Importing ::

import "github.com/serialx/hashring"

Basic example usage ::

memcacheServers := []string{"192.168.0.246:11212",
                            "192.168.0.247:11212",
                            "192.168.0.249:11212"}

ring := hashring.New(memcacheServers)
server := ring.GetNode("my_key")

Using weights example ::

weights := make(map[string]int)
weights["192.168.0.246:11212"] = 1
weights["192.168.0.247:11212"] = 2
weights["192.168.0.249:11212"] = 1

ring := hashring.NewWithWeights(weights)
server := ring.GetNode("my_key")

Adding and removing nodes example ::

memcacheServers := []string{"192.168.0.246:11212",
                            "192.168.0.247:11212",
                            "192.168.0.249:11212"}

ring := hashring.New(memcacheServers)
ring = ring.RemoveNode("192.168.0.246:11212")
ring = ring.AddNode("192.168.0.250:11212")
server := ring.GetNode("my_key")