bully

Implementation of the Bully Algorithm to elect a master among equal peers in a distributed system

Bully

node.js module to elect a master peer in a distributed system. This module uses the Bully Algorithm for the election process. Unresponsive/offline peers will be recognized through heartbeat timeouts.

Install via npm:

npm install bully

Include in your project

var Bully = require('bully');
 
var opts = { id: "id", /* unique identifier of this peer */
             peers: [], /* event emitter instances of other peers */
             me: me /* event emitter instance of local peer */
           }
 
var bully = new Bully(opts);
 
bully.on("master", function () {
    console.dir('I am now the master');
});
bully.on("stepped_down", function () {
    console.dir('Unfortunately I had to step down from my responsibilities');
});
 
var EventEmitter = require('events').EventEmitter;
 
var peer = new EventEmitter();
peer.id = 'anoter_unique_id';
 
bully.addPeer(peer);
bully.removePeer("peers_unique_id");
bully.on("error", function (err) {
    // handle error here 
});

Errors:

  • Unknown Peer: triggered once a message is received from an unknown

See example.js. Run with full debug information as follows:

DEBUG=bully npm test