diff --git a/source/portal/index.js b/source/portal/index.js
index ad32d1e37..cf64acb28 100644
--- a/source/portal/index.js
+++ b/source/portal/index.js
@@ -62,10 +62,7 @@ global.config = config;
 
 
 var amqper = require('./amqpClient')();
-var rpcClient;
-var socketio_server;
-var portal;
-var worker;
+
 
 var ip_address;
 (function getPublicIP() {
@@ -103,224 +100,275 @@ var ip_address;
   }
 })();
 
-var dropAll = function() {
-  socketio_server && socketio_server.drop('all');
-};
-
-var getTokenKey = function(id, on_key, on_error) {
-  var dataAccess = require('./data_access');
-  dataAccess.token.key(id).then(function (key) {
-    on_key(key);
-  }).catch(function (err) {
-    log.info('Failed to get token key. err:', (err && err.message) ? err.message : err);
-    on_error(err);
-  });
-};
-
-var joinCluster = function (on_ok) {
-  var joinOK = on_ok;
-
-  var joinFailed = function (reason) {
-    log.error('portal join cluster failed. reason:', reason);
-    worker && worker.quit();
-    process.exit();
-  };
+// Mutiple process setup
+const { setupMaster, setupWorker } = require("@socket.io/sticky");
+const { createAdapter, setupPrimary } = require("@socket.io/cluster-adapter");
+var cluster = require("cluster");
+var numCPUs = 4;
 
-  var loss = function () {
-    log.info('portal lost.');
-    dropAll();
-  };
-
-  var recovery = function () {
-    log.info('portal recovered.');
-  };
+if (cluster.isMaster) {
+  // Master Process
+  const httpServer = require('http').createServer();
 
-  var spec = {rpcClient: rpcClient,
-              purpose: 'portal',
-              clusterName: config.cluster.name,
-              joinRetry: config.cluster.join_retry,
-              info: {ip: ip_address,
-                     hostname: config.portal.hostname,
-                     port: config.portal.port,
-                     via_host: config.portal.via_host,
-                     ssl: config.portal.ssl,
-                     state: 2,
-                     max_load: config.cluster.max_load,
-                     capacity: config.capacity
-                    },
-              onJoinOK: joinOK,
-              onJoinFailed: joinFailed,
-              onLoss: loss,
-              onRecovery: recovery,
-              loadCollection: {period: config.cluster.report_load_interval,
-                               item: {name: 'cpu'}}
-             };
+  setupMaster(httpServer, {
+    loadBalancingMethod: "least-connection", // either "random", "round-robin" or "least-connection"
+  });
 
-  worker = require('./clusterWorker')(spec);
-};
+  setupPrimary();
+  
+  cluster.setupMaster({
+    serialization: "advanced",
+  });
 
-var refreshTokenKey = function(id, portal, tokenKey) {
-  var interval = setInterval(function() {
-    getTokenKey(id, function(newTokenKey) {
-      (socketio_server === undefined) && clearInterval(interval);
-      if (newTokenKey !== tokenKey) {
-        log.info('Token key updated!');
-        portal.updateTokenKey(newTokenKey);
-        tokenKey = newTokenKey;
-      }
-    }, function() {
-      (socketio_server === undefined) && clearInterval(interval);
-      log.warn('Keep trying...');
-    });
-  }, 6 * 1000);
-};
+  httpServer.listen(config.portal.port);
 
-var serviceObserver = {
-  onJoin: function(tokenCode) {
-    worker && worker.addTask(tokenCode);
-  },
-  onLeave: function(tokenCode) {
-    worker && worker.removeTask(tokenCode);
+  for (var i = 0; i < numCPUs; i++) {
+    cluster.fork();
   }
-};
-
-var startServers = function(id, tokenKey) {
-  var rpcChannel = require('./rpcChannel')(rpcClient);
-  var rpcReq = require('./rpcRequest')(rpcChannel);
 
-  portal = require('./portal')({tokenKey: tokenKey,
-                                tokenServer: 'ManagementApi',
-                                clusterName: config.cluster.name,
-                                selfRpcId: id},
-                                rpcReq);
-  socketio_server = require('./socketIOServer')({port: config.portal.port,
-                                                 cors: config.portal.cors,
-                                                 ssl: config.portal.ssl,
-                                                 forceTlsv12: config.portal.force_tls_v12,
-                                                 keystorePath: config.portal.keystorePath,
-                                                 reconnectionTicketLifetime: config.portal.reconnection_ticket_lifetime,
-                                                 reconnectionTimeout: config.portal.reconnection_timeout,
-                                                 pingInterval: config.portal.ping_interval,
-                                                 pingTimeout: config.portal.ping_timeout},
-                                                 portal,
-                                                 serviceObserver);
-  return socketio_server.start()
-    .then(function() {
-      log.info('start socket.io server ok.');
-      refreshTokenKey(id, portal, tokenKey);
-    })
-    .catch(function(err) {
-      log.error('Failed to start servers, reason:', err && err.message);
-      throw err;
+  cluster.on('exit', function(worker, code, signal) {
+      log.info(`Worker ${worker.process.pid} died`);
+  });  
+  
+  ['SIGINT', 'SIGTERM'].map(function (sig) {
+    process.on(sig, function () {
+            log.info('Master exiting on', sig);
+            process.exit();
+        });
     });
-};
 
-var stopServers = function() {
-  socketio_server && socketio_server.stop();
-  socketio_server = undefined;
-  worker && worker.quit();
-  worker = undefined;
-};
-
-var rpcPublic = {
-  drop: function(participantId, callback) {
-    socketio_server && socketio_server.drop(participantId);
-    callback('callback', 'ok');
-  },
-  notify: function(participantId, event, data, callback) {
-    // The "notify" is called on socket.io server,
-    // but one client ID should not be exists in both servers,
-    // there must be one failure, ignore this notify error here.
-    var notifyFail = (err) => {};
-    socketio_server && socketio_server.notify(participantId, event, data).catch(notifyFail);
-    callback('callback', 'ok');
-  },
-  validateAndDeleteWebTransportToken: (token, callback) => {
-    if(portal.validateAndDeleteWebTransportToken(token)) {
-      callback('callback','ok');
-    } else {
-      callback('callback', 'error', 'Invalid token for WebTransport.');
+    process.on('SIGUSR2', function() {
+        logger.reconfigure();
+    });
+}else{
+  // Worker Process
+  var rpcClient;
+  var socketio_server;
+  var portal;
+  var worker;
+  
+  var dropAll = function() {
+    socketio_server && socketio_server.drop('all');
+  };
+  
+  var getTokenKey = function(id, on_key, on_error) {
+    var dataAccess = require('./data_access');
+    dataAccess.token.key(id).then(function (key) {
+      on_key(key);
+    }).catch(function (err) {
+      log.info('Failed to get token key. err:', (err && err.message) ? err.message : err);
+      on_error(err);
+    });
+  };
+  
+  var joinCluster = function (on_ok) {
+    var joinOK = on_ok;
+  
+    var joinFailed = function (reason) {
+      log.error('portal join cluster failed. reason:', reason);
+      worker && worker.quit();
+      process.exit();
+    };
+  
+    var loss = function () {
+      log.info('portal lost.');
+      dropAll();
+    };
+  
+    var recovery = function () {
+      log.info('portal recovered.');
+    };
+  
+    var spec = {rpcClient: rpcClient,
+                purpose: 'portal',
+                clusterName: config.cluster.name,
+                joinRetry: config.cluster.join_retry,
+                info: {ip: ip_address,
+                       hostname: config.portal.hostname,
+                       port: config.portal.port,
+                       via_host: config.portal.via_host,
+                       ssl: config.portal.ssl,
+                       state: 2,
+                       max_load: config.cluster.max_load,
+                       capacity: config.capacity
+                      },
+                onJoinOK: joinOK,
+                onJoinFailed: joinFailed,
+                onLoss: loss,
+                onRecovery: recovery,
+                loadCollection: {period: config.cluster.report_load_interval,
+                                 item: {name: 'cpu'}}
+               };
+  
+    worker = require('./clusterWorker')(spec);
+  };
+  
+  var refreshTokenKey = function(id, portal, tokenKey) {
+    var interval = setInterval(function() {
+      getTokenKey(id, function(newTokenKey) {
+        (socketio_server === undefined) && clearInterval(interval);
+        if (newTokenKey !== tokenKey) {
+          log.info('Token key updated!');
+          portal.updateTokenKey(newTokenKey);
+          tokenKey = newTokenKey;
+        }
+      }, function() {
+        (socketio_server === undefined) && clearInterval(interval);
+        log.warn('Keep trying...');
+      });
+    }, 6 * 1000);
+  };
+  
+  var serviceObserver = {
+    onJoin: function(tokenCode) {
+      worker && worker.addTask(tokenCode);
+    },
+    onLeave: function(tokenCode) {
+      worker && worker.removeTask(tokenCode);
     }
-  },
-  broadcast: function(controller, excludeList, event, data, callback) {
-    socketio_server && socketio_server.broadcast(controller, excludeList, event, data);
-    callback('callback', 'ok');
-  }
-};
+  };
+  
+  var startServers = function(id, tokenKey) {
+    var rpcChannel = require('./rpcChannel')(rpcClient);
+    var rpcReq = require('./rpcRequest')(rpcChannel);
+  
+    portal = require('./portal')({tokenKey: tokenKey,
+                                  tokenServer: 'ManagementApi',
+                                  clusterName: config.cluster.name,
+                                  selfRpcId: id},
+                                  rpcReq);
+    socketio_server = require('./socketIOServer')({port: config.portal.port,
+                                                   cors: config.portal.cors,
+                                                   ssl: config.portal.ssl,
+                                                   forceTlsv12: config.portal.force_tls_v12,
+                                                   keystorePath: config.portal.keystorePath,
+                                                   reconnectionTicketLifetime: config.portal.reconnection_ticket_lifetime,
+                                                   reconnectionTimeout: config.portal.reconnection_timeout,
+                                                   pingInterval: config.portal.ping_interval,
+                                                   pingTimeout: config.portal.ping_timeout},
+                                                   portal,
+                                                   serviceObserver);
+    return socketio_server.start()
+      .then(function() {
+        log.info('start socket.io server ok.');
+        socketio_server.setupWorkerAdapter();
+        refreshTokenKey(id, portal, tokenKey);
+      })
+      .catch(function(err) {
+        log.error('Failed to start servers, reason:', err && err.message);
+        throw err;
+      });
+  };
+  
+  var stopServers = function() {
+    socketio_server && socketio_server.stop();
+    socketio_server = undefined;
+    worker && worker.quit();
+    worker = undefined;
+  };
+  
+  var rpcPublic = {
+    drop: function(participantId, callback) {
+      socketio_server && socketio_server.drop(participantId);
+      callback('callback', 'ok');
+    },
+    notify: function(participantId, event, data, callback) {
+      // The "notify" is called on socket.io server,
+      // but one client ID should not be exists in both servers,
+      // there must be one failure, ignore this notify error here.
+      var notifyFail = (err) => {};
+      socketio_server && socketio_server.notify(participantId, event, data).catch(notifyFail);
+      callback('callback', 'ok');
+    },
+    validateAndDeleteWebTransportToken: (token, callback) => {
+      if(portal.validateAndDeleteWebTransportToken(token)) {
+        callback('callback','ok');
+      } else {
+        callback('callback', 'error', 'Invalid token for WebTransport.');
+      }
+    },
+    broadcast: function(controller, excludeList, event, data, callback) {
+      socketio_server && socketio_server.broadcast(controller, excludeList, event, data);
+      callback('callback', 'ok');
+    }
+  };
 
-amqper.connect(config.rabbit, function () {
-  amqper.asRpcClient(function(rpcClnt) {
-    rpcClient = rpcClnt;
-    log.info('portal initializing as rpc client ok');
-    joinCluster(function(id) {
-      log.info('portal join cluster ok, with rpcID:', id);
-        amqper.asRpcServer(id, rpcPublic, function(rpcSvr) {
-          log.info('portal initializing as rpc server ok');
-            amqper.asMonitor(function (data) {
-              if (data.reason === 'abnormal' || data.reason === 'error' || data.reason === 'quit') {
-                if (portal !== undefined) {
-                  if (data.message.purpose === 'conference') {
-                    return portal.getParticipantsByController(data.message.type, data.message.id)
-                      .then(function (impactedParticipants) {
-                        impactedParticipants.forEach(function(participantId) {
-                          log.error('Fault on conference controller(type:', data.message.type, 'id:', data.message.id, ') of participant', participantId, 'was detected, drop it.');
-                          socketio_server && socketio_server.drop(participantId);
+  amqper.connect(config.rabbit, function () {
+    amqper.asRpcClient(function(rpcClnt) {
+      rpcClient = rpcClnt;
+      log.info('portal initializing as rpc client ok');
+      joinCluster(function(id) {
+        log.info('portal join cluster ok, with rpcID:', id);
+          amqper.asRpcServer(id, rpcPublic, function(rpcSvr) {
+            log.info('portal initializing as rpc server ok');
+              amqper.asMonitor(function (data) {
+                if (data.reason === 'abnormal' || data.reason === 'error' || data.reason === 'quit') {
+                  if (portal !== undefined) {
+                    if (data.message.purpose === 'conference') {
+                      return portal.getParticipantsByController(data.message.type, data.message.id)
+                        .then(function (impactedParticipants) {
+                          impactedParticipants.forEach(function(participantId) {
+                            log.error('Fault on conference controller(type:', data.message.type, 'id:', data.message.id, ') of participant', participantId, 'was detected, drop it.');
+                            socketio_server && socketio_server.drop(participantId);
+                          });
                         });
-                      });
+                    }
                   }
                 }
-              }
-            }, function (monitor) {
-              log.info(id + ' as monitor ready');
-              getTokenKey(id, function(tokenKey) {
-                startServers(id, tokenKey);
-              }, function() {
-                log.error('portal getting token failed.');
+              }, function (monitor) {
+                log.info(id + ' as monitor ready');
+                getTokenKey(id, function(tokenKey) {
+                  startServers(id, tokenKey);
+                }, function() {
+                  log.error('portal getting token failed.');
+                  stopServers();
+                  process.exit();
+                });
+              }, function(reason) {
+                log.error('portal initializing as monitor failed, reason:', reason);
                 stopServers();
                 process.exit();
               });
-            }, function(reason) {
-              log.error('portal initializing as rpc client failed, reason:', reason);
-              stopServers();
-              process.exit();
-            });
-      }, function(reason) {
-        log.error('portal initializing as rpc client failed, reason:', reason);
-        stopServers();
-        process.exit();
+        }, function(reason) {
+          log.error('portal initializing as rpc server failed, reason:', reason);
+          stopServers();
+          process.exit();
+        });
       });
+    }, function(reason) {
+      log.error('portal initializing as rpc client failed, reason:', reason);
+      stopServers();
+      process.exit();
     });
   }, function(reason) {
-    log.error('portal initializing as rpc client failed, reason:', reason);
-    stopServers();
-    process.exit();
+      log.error('portal connect to rabbitMQ server failed, reason:', reason);
+      process.exit();
   });
-}, function(reason) {
-    log.error('portal connect to rabbitMQ server failed, reason:', reason);
-    process.exit();
-});
 
-['SIGINT', 'SIGTERM'].map(function (sig) {
-  process.on(sig, async function () {
-    log.warn('Exiting on', sig);
-    stopServers();
-    amqper.disconnect();
-    process.exit();
+  log.info(`Worker ${process.pid} started`);
+
+  ['SIGINT', 'SIGTERM'].map(function (sig) {
+    process.on(sig, async function () {
+      log.warn('Worker exiting on', sig);
+      stopServers();
+      amqper.disconnect();
+      process.exit();
+    });
   });
-});
 
-process.on('SIGPIPE', function () {
-  log.warn('SIGPIPE!!');
-});
+  process.on('SIGPIPE', function () {
+    log.warn('SIGPIPE!!');
+  });
 
-process.on('exit', function () {
-  log.info('Process exit');
-});
+  process.on('exit', function () {
+    log.info('Process exit');
+  });
 
-process.on('unhandledRejection', (reason) => {
+  process.on('unhandledRejection', (reason) => {
     log.info('Reason: ' + reason);
-});
+  });
 
-process.on('SIGUSR2', function () {
-  logger.reconfigure();
-});
+  process.on('SIGUSR2', function() {
+      logger.reconfigure();
+  });
+}
diff --git a/source/portal/package.json b/source/portal/package.json
index 8898289d7..2ce6feea8 100644
--- a/source/portal/package.json
+++ b/source/portal/package.json
@@ -4,6 +4,8 @@
   "dependencies": {
     "amqplib": "^0.7.0",
     "socket.io": "^3.1.1",
+    "@socket.io/sticky": "*",
+    "@socket.io/cluster-adapter": "*",
     "log4js": "^1.1.1",
     "toml": "*",
     "sprintf-js": "^1.0.3",
diff --git a/source/portal/socketIOServer.js b/source/portal/socketIOServer.js
index e65f5417f..d8911c77a 100644
--- a/source/portal/socketIOServer.js
+++ b/source/portal/socketIOServer.js
@@ -369,6 +369,8 @@ var SocketIOServer = function(spec, portal, observer) {
   var that = {};
   var io;
   var clients = {};
+  const { setupMaster, setupWorker } = require("@socket.io/sticky");
+  const { createAdapter, setupPrimary } = require("@socket.io/cluster-adapter");
   // A Socket.IO server has a unique reconnection key. Client cannot reconnect to another Socket.IO server in the cluster.
   var reconnection_key = require('crypto').randomBytes(64).toString('hex');
   var sioOptions = {};
@@ -391,7 +393,7 @@ var SocketIOServer = function(spec, portal, observer) {
   }
 
   var startInsecure = function(port) {
-    var server = require('http').createServer().listen(port);
+    var server = require('http').createServer();//.listen(port);
     io = require('socket.io')(server, sioOptions);
     run();
     return Promise.resolve('ok');
@@ -408,7 +410,7 @@ var SocketIOServer = function(spec, portal, observer) {
             var constants = require('constants');
             option.secureOptions = (constants.SSL_OP_NO_TLSv1 | constants.SSL_OP_NO_TLSv1_1);
           }
-          var server = require('https').createServer(option).listen(port);
+          var server = require('https').createServer(option);//.listen(port);
           io = require('socket.io')(server, sioOptions);
           run();
           resolve('ok');
@@ -470,6 +472,11 @@ var SocketIOServer = function(spec, portal, observer) {
     io = undefined;
   };
 
+  that.setupWorkerAdapter = function() {
+    io && io.adapter(createAdapter());
+    setupWorker(io);
+  };
+
   that.notify = function(participantId, event, data) {
     log.debug('notify participant:', participantId, 'event:', event, 'data:', data);
     if (clients[participantId]) {