cluster-proxy

Abstracts method calling on an object in the master process. The workers have a proxy object that abstracts all the message passing. The main limitation is that arguments and values must be JSON serializable.

Usage no npm install needed!

<script type="module">
  import clusterProxy from 'https://cdn.skypack.dev/cluster-proxy';
</script>

README

This module allows a clusterized node.js application to have a shared object between the master and worker processes.

Internally it uses message passing and JSON serialization of arguments and return values, so the abstraction is not perfect (objects like file references, sockets, bound functions, etc. cannot be passed around).

You can read the full generated jsdoc here: http://bazaarvoice.github.io/node-cluster-proxy/out/index.html

Example of usage

var cluster = require('cluster');
var clusterproxy = require('cluster-proxy');
if (cluster.isMaster) {
  var delegate = {
    a : 42,
    f : function(a, b) {
      return a + b;
    },
    g : function(a, cb) {
      cb(null, a*2, a*a);
    }
  };
  var master = new clusterproxy.Master({delegate: delegate});
  master.connectWorker(cluster.fork());
} else { //worker process
  var proxy = new clusterproxy.Worker();
  proxy.get('a', console.log);
  proxy.invoke('f', 1, 2, console.log);
  proxy.invokeAsync('g',//method name
                     21,//argument for the invoked method
                     function(proxyErr, delegateErr, double, square) {//callback: note that we have two error arguments, one for the cluster proxy itself (timeouts, etc.) and another for the delegate errors.
    if(!proxyErr && !delegateErr) {
      console.log('double:', double, 'square:', square);
    } else {
      console.log('error:', proxyErr || delegateErr);
    }
  });
}

Running tests

There is a monolithic test file that can be run as a normal nodejs script, or directly with npm test

TO-DO

  • Support for returned promises in delegate objects
  • Return promises in the clients