added cluster module to node-windshaft

cluster.js

@@ -0,0 +1,44 @@
+/*
+ * Windshaft-CartoDB
+ * ===============
+ *
+ * ./app.js [environment]
+ *
+ * environments: [development, production]
+ */
+
+var cluster = require('cluster');
+
+// sanity check
+var ENV = process.argv[2]
+if (ENV != 'development' && ENV != 'production'){
+    console.error("\nnode app.js [environment]");
+    console.error("environments: [development, production]\n");
+    process.exit(1);
+}
+
+var _ = require('underscore')
+    , Step       = require('step')
+    , cartoData  = require('./lib/cartodb/carto_data')
+	, CartodbWindshaft = require('./lib/cartodb/cartodb_windshaft');
+    
+
+
+// set environment specific variables
+global.settings     = require(__dirname + '/config/settings');
+global.environment  = require(__dirname + '/config/environments/' + ENV);
+_.extend(global.settings, global.environment);
+
+var Windshaft = require('windshaft');
+var serverOptions = require('./lib/cartodb/server_options');
+
+ws = CartodbWindshaft(serverOptions);
+cluster(ws)
+  .use(cluster.logger('logs'))
+  .use(cluster.stats())
+  .use(cluster.pidfiles('pids'))
+  .set('workers', 1)
+  .listen(global.environment.windshaft_port);
+
+//ws.listen(global.environment.windshaft_port);
+console.log("Windshaft tileserver started on port " + global.environment.windshaft_port);

package.json

@@ -15,6 +15,7 @@
       "email": "simon@vizzuality.com"
     },
     "dependencies": {
+        "cluster": "0.6.4",
         "node-varnish": "0.1.0",
         "underscore"  : "1.1.x",
         "windshaft"  : "0.4.3",