Dnode cluster

cluster.js

var dnode = require('dnode');


var Cluster = function(options) { /* Options : local port, host, remote nodes, ... */
    var _self = this;
    this.options = options;

    /* the remote server connected with this server */
    this.connectedPeers = [];

    /* Exposed functions */
    this._server = dnode({

      /** 
       * Method called by other nodes to say hello 
       * and transmit their respective connectedPeers in order to merge
       * the cluster.
       */
      __hello: function(remote, remoteConnectedPeers) {
        //TODO try to share the connection remote to me === me to remote
        _self._connect(remote.host, remote.port);
        remoteConnectedPeers.forEach(function(peer) {
          _self._connect(peer.host, peer.port);
        });
      }
    });

    /** 
     * Start listening + try to join the other cluster members 
     * every `options.refresh` ms 
     */
    this.start = function() {
      _self._listen();
      setInterval(function() {
        _self.join.apply(_self);
      }, _self.options.refresh);
    };

    /** Start listening */
    this._listen = function() {
      console.log(_self.toString() + " listening");
      _self._server.listen(_self.options.local.port);
    };

    /** 
     * Connect to a remote server and send my connected peers to merge
     * the cluster.
     */
    this._connect = function(host, port) {
      if (!_self._isMe(host, port)) {
        if (!_self._isPeerConnected(host, port)) {
          console.log(_self.toString() + " tring to connect on " + host + ":" + port);
          dnode.connect(port, function(remote) {
            console.log(_self.toString() + " connected with " + host + ":" + port + " !");
            _self.connectedPeers.push({
              host: host,
              port: port
            });
            remote.__hello(_self.options.local, _self.connectedPeers);
          });
        }
      }
    };

    /** return true if this server is connected with this host:port */
    this._isPeerConnected = function(host, port) {
      var returnValue = false;
      _self.connectedPeers.forEach(function(peer){
        if (peer.host == host && peer.port == port) {
          returnValue = true;
        }
      });
      return returnValue;
    }; 
    
    /** return true if this server is connected with this host:port */
    this._isMe = function(host, port) {
      if (host == _self.options.local.host && port == _self.options.local.port) {
        return true;
      }

      return false;
    };

    /** Join the other nodes of the cluster */
    this.join = function() {
      _self.options.remote.forEach(function(remote) {

        _self._connect(remote.host, remote.port);
      });

    };

    /** return your-ip:port */
    this.toString = function() {
      return _self.options.local.host + ":" + _self.options.local.port;
    };

    };

module.exports = Cluster;

clusterExample

var cluster = require('./cluster');

console.log(cluster);

var a = new cluster({
  local: {
    host: '127.0.0.1',
    port: 3333
  },

  remote: [{
    host: '127.0.0.1',
    port: 4444
  }, {
    host: '127.0.0.1',
    port: 5555
  }],
  
  refresh: 1000
});

a.start();

var b = new cluster({
  local: {
    host: '127.0.0.1',
    port: 4444
  },

  remote: [],
  
  refresh: 1000
});

b.start();

var c = new cluster({
  local: {
    host: '127.0.0.1',
    port: 5555
  },

  remote: [],
  
  refresh: 1000
});

c.start();

The output is :

127.0.0.1:3333 listening
127.0.0.1:4444 listening
127.0.0.1:5555 listening
127.0.0.1:3333 tring to connect on 127.0.0.1:4444
127.0.0.1:3333 tring to connect on 127.0.0.1:5555
127.0.0.1:3333 connected with 127.0.0.1:5555 !
127.0.0.1:3333 connected with 127.0.0.1:4444 !
127.0.0.1:4444 tring to connect on 127.0.0.1:3333
127.0.0.1:4444 tring to connect on 127.0.0.1:5555
127.0.0.1:5555 tring to connect on 127.0.0.1:3333
127.0.0.1:5555 connected with 127.0.0.1:3333 !
127.0.0.1:4444 connected with 127.0.0.1:5555 !
127.0.0.1:4444 connected with 127.0.0.1:3333 !
127.0.0.1:5555 tring to connect on 127.0.0.1:4444
127.0.0.1:5555 connected with 127.0.0.1:4444 !