diff --git a/bin/www b/bin/www
index f0289d3..d0ac0c2 100644
--- a/bin/www
+++ b/bin/www
@@ -15,102 +15,114 @@ config.https = config.https || {};
 const logger = require('morgan');
 const debug = require('debug')('pep-proxy:app');
 const express = require('express');
+const os = require('os');
+const cluster = require('cluster');
+const clusterWorkerSize = os.cpus().length;
 
-process.on('uncaughtException', function(err) {
+process.on('uncaughtException', function (err) {
   debug('Caught exception: ' + err);
 });
 process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0';
 
-const app = express();
-
-// Set logs in development
-if (config.debug) {
-  app.use(logger('dev'));
-}
-
-//app.use(express.bodyParser());
-
-app.use(function(req, res, next) {
-  const bodyChunks = [];
-  req.on('data', function(chunk) {
-    bodyChunks.push(chunk);
-  });
-
-  req.on('end', function() {
-    if (bodyChunks.length > 0) {
-      req.body = Buffer.concat(bodyChunks);
-    }
-    next();
-  });
-});
-
-app.disable('x-powered-by');
-app.use(errorhandler({ log: debug}));
-app.use(cors(config.cors));
-
 let port = config.pep_port || 80;
 if (config.https.enabled) {
   port = config.https.port || 443;
 }
-app.set('port', port);
 
-for (const p in config.public_paths) {
-  debug('Public paths', config.public_paths[p]);
-  app.all(config.public_paths[p], Root.public);
-}
+function start_server() {
+  const app = express();
 
-app.all('/*', Root.pep);
+  // Set logs in development
+  if (config.debug) {
+    app.use(logger('dev'));
+  }
 
+  app.use(function (req, res, next) {
+    const bodyChunks = [];
+    req.on('data', function (chunk) {
+      bodyChunks.push(chunk);
+    });
 
-function connectIDM(callback) {
-  IDM.authenticate(
-    function(token) {
-      debug('Success authenticating PEP proxy. Proxy Auth-token: ', token);
-      callback();
-    },
-    function(status, e) {
-      debug('Error in IDM communication', e);
-      callback(e);
-    }
-  );
-}
+    req.on('end', function () {
+      if (bodyChunks.length > 0) {
+        req.body = Buffer.concat(bodyChunks);
+      }
+      next();
+    });
+  });
 
-if (config.https.enabled === true) {
-  const options = {
-    key: fs.readFileSync(config.https.key_file),
-    cert: fs.readFileSync(config.https.cert_file),
-  };
-
-  https
-    .createServer(options, function(req, res) {
-      app.handle(req, res);
-    })
-    .listen(app.get('port'));
-} else {
-  app.listen(app.get('port'));
+  app.disable('x-powered-by');
+  app.use(errorhandler({ log: debug }));
+  app.use(cors(config.cors));
+  app.set('port', port);
+
+  for (const p in config.public_paths) {
+    debug('Public paths', config.public_paths[p]);
+    app.all(config.public_paths[p], Root.public);
+  }
+
+  app.all('/*', Root.pep);
+
+  if (config.https.enabled === true) {
+    const options = {
+      key: fs.readFileSync(config.https.key_file),
+      cert: fs.readFileSync(config.https.cert_file)
+    };
+
+    https
+      .createServer(options, function (req, res) {
+        app.handle(req, res);
+      })
+      .listen(app.get('port'));
+  } else {
+    app.listen(app.get('port'));
+  }
 }
 
-let retry = 20;
 function connect() {
-  const connect_with_retry = () => {
-    connectIDM((err) => {
-      if (err) {
-        retry--;
-        if (retry === 0) {
-          debug('Error found after [%d] attempts: %s', 20, error);
-          process.exit(1);
-        } else {
-          console.log('retry after 5 seconds.');
-          //eslint-disable-next-line snakecase/snakecase
-          setTimeout(connect_with_retry, 5000);
+  let retry = 20;
+  return new Promise((resolve, reject) => {
+    const connect_with_retry = () => {
+      IDM.authenticate(
+        (token) => {
+          debug('Success authenticating PEP proxy.');
+          resolve(token);
+        },
+        (status, e) => {
+          debug('Error in IDM communication', e);
+          retry--;
+          if (retry === 0) {
+            reject(e);
+          } else {
+            debug('retry after 5 seconds.');
+            //eslint-disable-next-line snakecase/snakecase
+            setTimeout(connect_with_retry, 5000);
+          }
         }
-      } else {
-        debug('Success authenticating PEP proxy.');
-      }
-    });
-  };
-  connect_with_retry();
+      );
+    };
+    connect_with_retry();
+  });
 }
 
 debug('Starting PEP proxy in port ' + port + '. IdM authentication ...');
-connect();
+connect().then(
+  (token) => {
+    debug('Success authenticating PEP proxy. Proxy Auth-token: ', token);
+    if (clusterWorkerSize > 1) {
+      if (cluster.isMaster) {
+        for (let i = 0; i < clusterWorkerSize; i++) {
+          cluster.fork();
+        }
+      } else {
+        start_server();
+      }
+    } else {
+      start_server();
+    }
+  },
+  (err) => {
+    debug('Error found after [%d] attempts: %s', 20, err);
+    process.exit(1);
+  }
+);