consistent

Consistent hashing module for Node.JS

installation

npm install consistent

usage

var consistent = require('consistent');

var ring = consistent({
  members: [
    "member1",
    "member2",
    {
      key: "member3",
      weight: 1.5 // optional, default weight is 1
    }
  ],
  hash: 'md5' // can use 'md5' or 'murmurhash'
});

console.log(ring.get('some key'));
// outputs member1 or member2 or member3

api

add member

adds a new member

ring.add('member4');
// or
ring.add({
  key: "member4",
  weight: 3
})

remove member

removes a member

ring.remove("member2")

replace member

this preserves the hash slots of old member, if you want to recalculate hashes for the new member, just remove the old one and add the new one.

ring.replace('member1', 'member5');

get member for hash slot

ring.get('some key');
ring.getCached('some key'); //use lru cache

check if a member exists

ring.exists('member1') // returns true if a member has been added with name member1

get member count

ring.length; // returns number of members within the ring

author

Ekin Koc

license

MIT