Support binary messages over websocket

For now Zaqar's websocket transport can only send and receive text
messages in JSON format.
By using messages in binary format it's possible to reduce network
traffic between Zaqar server and it's clients. In most cases it's also
possible to increase performance.

This patch implements support for binary messages over websocket
transport in Zaqar server.
The MessagePack format was chosen for encoding/decoding messages as it's
effective enough and available in convenient libraries for most
programming languages.

This patch also modifies "examples/websockets.html" example to be able
to send and receive binary messages.

All "print" function calls are substituted to local logger calls.

DocImpact
APIImpact The patch adds new functionality. Now sending binary request
over websocket doesn't automatically return response with code 400,
because now websocket transport is able to process binary requests
encoded in MessagePack.
blueprint: websocket-binary-support
Change-Id: I07a7c46795e3b510ee397a6d2c4665e770c2c4b2

examples/websocket.html

@@ -6,6 +6,11 @@
         <meta charset='utf-8' />
         <link rel='stylesheet'  href='http://yui.yahooapis.com/pure/0.6.0/pure-nr-min.css' />
         <script type='text/javascript' src='http://code.jquery.com/jquery-2.1.4.min.js'></script>
+        <!--[if lte IE 9]>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/es5-shim/4.1.10/es5-shim.min.js"></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/json3/3.3.2/json3.min.js"></script>
+        <![endif]-->
+        <script src="https://rawgithub.com/kawanet/msgpack-lite/master/dist/msgpack.min.js"></script>
         <style>
         .pure-g > div {
             box-sizing: border-box;
@@ -39,28 +44,76 @@
         }
         </style>
         <script type='text/javascript'>
-        var socket = new WebSocket('ws://localhost:9000/');
-        var project = 'cf38008b72d04b89a505b9d66d1d5768';
+        // Parameters:
+        var server_url = 'ws://localhost:9000/';
+        var project_id = 'cf38008b72d04b89a505b9d66d1d5768';
         var client_id = '31209ff3-ba03-4cec-b4ca-655f4899f8f4';
-        socket.onopen = function(evt) {
+        var send_binary = true;
+
+        var socket = new WebSocket(server_url);
+        socket.binaryType = 'arraybuffer';
+
+        if (send_binary == true) {
+            // Use MessagePack(binary) for encoding messages
+            encode = function(data) {
+                return msgpack.encode(data);
+            }
+        } else {
+            // Use JSON(text) for encoding messages
+            encode = function(data) {
+                return JSON.stringify(data);
+            }
+        }
+        msgpack_decode = function(enc_data) {
+            return msgpack.decode(new Uint8Array(enc_data));
+        }
+        json_decode = function(enc_data) {
+            return JSON.parse(enc_data);
+        }
+        add_connection_info = function(msg) {
+            msg += ". Using parameters: Server URL: " + server_url;
+            msg += ". Project ID: " + project_id;
+            msg += ". Client ID: " + client_id;
+            msg += ". Binary communication: " + send_binary;
+            return msg
+        }
+        log_info = function(msg) {
             var node = document.createElement('div');
-            var msg = new Date().toUTCString();
-            msg += " Connection opened"
+            var date = new Date().toUTCString();
+            msg = date + " " + msg;
             node.appendChild(document.createTextNode(msg));
             $('#log').append(node);
         }
+        socket.onopen = function(evt) {
+            msg = "Connection opened";
+            msg = add_connection_info(msg);
+            log_info(msg);
+        }
+        socket.onclose = function(evt) {
+            msg = "Connection closed";
+            log_info(msg);
+        }
+        socket.onerror = function(evt) {
+            msg = "Connection error";
+            msg = add_connection_info(msg);
+            log_info(msg);
+        }
         socket.onmessage = function(evt) {
-            var node = document.createElement('div');
-            var msg = new Date().toUTCString();
-            var data = JSON.parse(evt.data);
+            if (evt.data instanceof ArrayBuffer) {
+                // Received payload in MessagePack(binary) format
+                var data = msgpack_decode(evt.data);
+            }
+            if (typeof evt.data === "string") {
+                // Received payload in JSON(text) format
+                var data = json_decode(evt.data);
+            }
             if ('request' in data && 'headers' in data) {
                 // Response received
                 var action = data["request"]["action"];
-                msg += " action: " + action;
+                msg = "action: " + action;
                 msg += " status: " + data["headers"]["status"];
                 msg += " body: " + JSON.stringify(data["body"]);
-                node.appendChild(document.createTextNode(msg));
-                $('#log').append(node);
+                log_info(msg);
                 if (action == 'queue_list') {
                     var queues = data['body']['queues'];
                     display_queues(queues);
@@ -75,12 +128,15 @@
                    list_messages();
                 }
             } else {
-                // Notification received
-                msg += " Got notification."
-                msg += " body: " + JSON.stringify(data["body"]);
-                node.appendChild(document.createTextNode(msg));
-                $('#log').append(node);
-                list_messages();
+                // Can be notification or unexpected data
+                if(data.hasOwnProperty('body')){
+                    msg = "notification: " + JSON.stringify(data);
+                    log_info(msg)
+                    list_messages();
+                } else {
+                    msg = "unexpected data: " + JSON.stringify(data);
+                    log_info(msg)
+                }
             }
         }
         login = function(frm) {
@@ -106,26 +162,43 @@
                 'dataType': 'json',
                 'success': function(data, code, response) {
                     var token = response.getResponseHeader('X-Subject-Token')
-                    var msg = {'action': 'authenticate',
-                               'headers': {'X-Auth-Token': token,
-                                           'Client-ID': client_id,
-                                           'X-Project-ID': project}}
-                    socket.send(JSON.stringify(msg));
+                    if (token == null){
+                        log_info("Connected to Keystone, but no 'X-Subject-Token' "
+                        + "header was provided. Keystone's CORS filter is probably "
+                        + "not configured to expose this header.");
+                    } else {
+                        log_info("Got token from Keystone. " +
+                        "Sending authentication request to Zaqar.");
+                        var msg = {'action': 'authenticate',
+                                   'headers': {'X-Auth-Token': token,
+                                               'Client-ID': client_id,
+                                               'X-Project-ID': project_id}}
+                        socket.send(encode(msg));
+                     };
+                },
+                'error': function(data, code, errorThrown) {
+                    if (errorThrown) {
+                        log_info("Keystone error: " + errorThrown);
+                    } else {
+                        log_info("Failed to connect to Keystone. Keystone is either" +
+                        " offline, or CORS is not enabled in Keystone.");
+                    }
+
                 }
             });
             return false;
         }
         send_message = function(action, body) {
             var msg = {'action': action,
-                       'headers': {'Client-ID': client_id, 'X-Project-ID': project}}
+                       'headers': {'Client-ID': client_id, 'X-Project-ID':
+                       project_id}};
             if (body) {
                 msg['body'] = body;
-            }
-
-            socket.send(JSON.stringify(msg));
+            };
+            socket.send(encode(msg));
         }
         list_queues = function() {
-            send_message('queue_list')
+            send_message('queue_list');
         }
         create_queue = function(frm) {
             send_message('queue_create', {'queue_name': frm['queue'].value});
@@ -153,19 +226,19 @@
             send_message('queue_delete', {'queue_name': get_selected_queue()});
         }
         list_messages = function() {
-            send_message('message_list', {'queue_name': get_selected_queue(), 'echo': true})
+            send_message('message_list', {'queue_name': get_selected_queue(), 'echo': true});
         }
         queue_message = function(frm) {
             var body = frm['body'].value;
             var ttl = parseInt(frm['ttl'].value);
-            send_message('message_post', {'queue_name': get_selected_queue(), 'messages': [{'body': body, 'ttl': ttl}]})
+            send_message('message_post', {'queue_name': get_selected_queue(), 'messages': [{'body': body, 'ttl': ttl}]});
             return false;
         }
         delete_message = function(message_id) {
             send_message('message_delete', {'queue_name': get_selected_queue(), 'message_id': message_id});
         }
         subscribe_queue = function() {
-            send_message('subscription_create', {'queue_name': get_selected_queue(), 'ttl': 3600})
+            send_message('subscription_create', {'queue_name': get_selected_queue(), 'ttl': 3600});
         }
         </script>
     </head>

zaqar/tests/etc/websocket_mongodb_subscriptions.conf

@@ -0,0 +1,23 @@
+[DEFAULT]
+unreliable = True
+
+[drivers]
+
+# Transport driver to use (string value)
+transport = websocket
+
+# Storage driver to use (string value)
+message_store = mongodb
+
+[drivers:management_store:mongodb]
+
+# Mongodb Connection URI
+uri = mongodb://127.0.0.1:27017
+
+[drivers:message_store:mongodb]
+
+# Mongodb Connection URI
+uri = mongodb://127.0.0.1:27017
+
+[storage]
+message_pipeline = zaqar.notification.notifier

zaqar/tests/unit/transport/websocket/test_protocol.py

@@ -14,22 +14,27 @@
 #    under the License.
 
 import json
+import uuid
 
+import ddt
 import mock
 
 from zaqar.tests.unit.transport.websocket import base
+from zaqar.tests.unit.transport.websocket import utils as test_utils
 
 
+@ddt.ddt
 class TestMessagingProtocol(base.TestBase):
     config_file = "websocket_mongodb.conf"
 
     def setUp(self):
         super(TestMessagingProtocol, self).setUp()
         self.protocol = self.transport.factory()
-        self.defaults = self.api.get_defaults()
-
-    def tearDown(self):
-        super(TestMessagingProtocol, self).tearDown()
+        self.project_id = 'protocol-test'
+        self.headers = {
+            'Client-ID': str(uuid.uuid4()),
+            'X-Project-ID': self.project_id
+        }
 
     def test_on_message_with_invalid_input(self):
         payload = u'\ufeff'
@@ -45,3 +50,45 @@ class TestMessagingProtocol(base.TestBase):
         self.protocol.onMessage(payload, False)
         resp = json.loads(send_mock.call_args[0][0])
         self.assertEqual(400, resp['headers']['status'])
+
+    def test_on_message_with_invalid_input_binary(self):
+        dumps, loads, create_req = test_utils.get_pack_tools(binary=True)
+        send_mock = mock.Mock()
+        self.protocol.sendMessage = send_mock
+
+        # Test error response, when the request can't be deserialized.
+        req = "123"
+        self.protocol.onMessage(req, True)
+        resp = loads(send_mock.call_args[0][0])
+        self.assertEqual(400, resp['headers']['status'])
+        self.assertIn('Can\'t decode binary', resp['body']['error'])
+
+        # Test error response, when request body is not a dictionary.
+        req = dumps("Apparently, I'm not a dictionary")
+        self.protocol.onMessage(req, True)
+        resp = loads(send_mock.call_args[0][0])
+        self.assertEqual(400, resp['headers']['status'])
+        self.assertIn('Unexpected body type. Expected dict',
+                      resp['body']['error'])
+
+        # Test error response, when validation fails.
+        action = 'queue_glorify'
+        body = {}
+        req = create_req(action, body, self.headers)
+        self.protocol.onMessage(req, True)
+        resp = loads(send_mock.call_args[0][0])
+        self.assertEqual(400, resp['headers']['status'])
+        self.assertEqual('queue_glorify is not a valid action',
+                         resp['body']['error'])
+
+    @ddt.data(True, False)
+    def test_on_message_with_input_in_different_format(self, in_binary):
+        dumps, loads, create_req = test_utils.get_pack_tools(binary=in_binary)
+        action = 'queue_get'
+        body = {'queue_name': 'beautiful-non-existing-queue'}
+        req = create_req(action, body, self.headers)
+        send_mock = mock.Mock()
+        self.protocol.sendMessage = send_mock
+        self.protocol.onMessage(req, in_binary)
+        resp = loads(send_mock.call_args[0][0])
+        self.assertEqual(200, resp['headers']['status'])

zaqar/tests/unit/transport/websocket/utils.py

@@ -12,8 +12,37 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
+import functools
 import json
+import msgpack
 
 
 def create_request(action, body, headers):
     return json.dumps({"action": action, "body": body, "headers": headers})
+
+
+def create_binary_request(action, body, headers):
+    return msgpack.packb({"action": action, "body": body, "headers": headers})
+
+
+def get_pack_tools(binary=None):
+    """Get serialization tools for testing websocket transport.
+
+    :param bool binary: type of serialization tools.
+    True: binary (MessagePack) tools.
+    False: text (JSON) tools.
+    :returns: set of serialization tools needed for testing websocket
+    transport: (dumps, loads, create_request_function)
+    :rtype: tuple
+    """
+    if binary is None:
+        raise Exception("binary param is unspecified")
+    if binary:
+        dumps = msgpack.Packer(encoding='utf-8', use_bin_type=False).pack
+        loads = functools.partial(msgpack.unpackb, encoding='utf-8')
+        create_request_function = create_binary_request
+    else:
+        dumps = json.dumps
+        loads = json.loads
+        create_request_function = create_request
+    return dumps, loads, create_request_function

zaqar/tests/unit/transport/websocket/v2/test_auth.py

@@ -16,6 +16,7 @@
 import json
 import uuid
 
+import ddt
 from keystonemiddleware import auth_token
 import mock
 
@@ -24,8 +25,8 @@ from zaqar.tests.unit.transport.websocket import base
 from zaqar.tests.unit.transport.websocket import utils as test_utils
 
 
+@ddt.ddt
 class AuthTest(base.V2Base):
-
     config_file = "websocket_mongodb_keystone_auth.conf"
 
     def setUp(self):
@@ -87,6 +88,7 @@ class AuthTest(base.V2Base):
         msg_mock = mock.patch.object(self.protocol, 'sendMessage')
         self.addCleanup(msg_mock.stop)
         msg_mock = msg_mock.start()
+        self.protocol._auth_in_binary = False
         self.protocol._auth_response('401 error', 'Failed')
         self.assertEqual(1, msg_mock.call_count)
         resp = json.loads(msg_mock.call_args[0][0])
@@ -122,6 +124,25 @@ class AuthTest(base.V2Base):
         self.assertIn('cancelled', repr(handle))
         self.assertNotIn('cancelled', repr(self.protocol._deauth_handle))
 
+    @ddt.data(True, False)
+    def test_auth_response_serialization_format(self, in_binary):
+        dumps, loads, create_req = test_utils.get_pack_tools(binary=in_binary)
+        headers = self.headers.copy()
+        headers['X-Auth-Token'] = 'mytoken1'
+        req = create_req("authenticate", {}, headers)
+
+        msg_mock = mock.patch.object(self.protocol, 'sendMessage')
+        self.addCleanup(msg_mock.stop)
+        msg_mock = msg_mock.start()
+        # Depending on onMessage method's second argument, auth response should
+        # be in binary or text format.
+        self.protocol.onMessage(req, in_binary)
+        self.assertEqual(in_binary, self.protocol._auth_in_binary)
+        self.protocol._auth_response('401 error', 'Failed')
+        self.assertEqual(1, msg_mock.call_count)
+        resp = loads(msg_mock.call_args[0][0])
+        self.assertEqual(401, resp['headers']['status'])
+
     def test_signed_url(self):
         send_mock = mock.Mock()
         self.protocol.sendMessage = send_mock

zaqar/tests/unit/transport/websocket/v2/test_messages.py

@@ -69,7 +69,7 @@ class MessagesBaseTest(base.V2Base):
         resp = json.loads(send_mock.call_args[0][0])
         self.assertEqual(204, resp['headers']['status'])
 
-    def _test_post(self, sample_messages):
+    def _test_post(self, sample_messages, in_binary=False):
         action = "message_post"
         body = {"queue_name": "kitkat",
                 "messages": sample_messages}
@@ -77,11 +77,13 @@ class MessagesBaseTest(base.V2Base):
         send_mock = mock.Mock()
         self.protocol.sendMessage = send_mock
 
-        req = test_utils.create_request(action, body, self.headers)
+        dumps, loads, create_req = test_utils.get_pack_tools(binary=in_binary)
 
-        self.protocol.onMessage(req, False)
+        req = create_req(action, body, self.headers)
 
-        resp = json.loads(send_mock.call_args[0][0])
+        self.protocol.onMessage(req, in_binary)
+
+        resp = loads(send_mock.call_args[0][0])
         self.assertEqual(201, resp['headers']['status'])
         self.msg_ids = resp['body']['message_ids']
         self.assertEqual(len(sample_messages), len(self.msg_ids))
@@ -102,19 +104,19 @@ class MessagesBaseTest(base.V2Base):
                 body = {"queue_name": "kitkat",
                         "message_id": msg_id}
 
-                req = test_utils.create_request(action, body, headers)
+                req = create_req(action, body, headers)
 
-                self.protocol.onMessage(req, False)
+                self.protocol.onMessage(req, in_binary)
 
-                resp = json.loads(send_mock.call_args[0][0])
+                resp = loads(send_mock.call_args[0][0])
                 self.assertEqual(404, resp['headers']['status'])
 
                 # Correct project ID
-                req = test_utils.create_request(action, body, self.headers)
+                req = create_req(action, body, self.headers)
 
-                self.protocol.onMessage(req, False)
+                self.protocol.onMessage(req, in_binary)
 
-                resp = json.loads(send_mock.call_args[0][0])
+                resp = loads(send_mock.call_args[0][0])
                 self.assertEqual(200, resp['headers']['status'])
 
                 # Check message properties
@@ -132,11 +134,11 @@ class MessagesBaseTest(base.V2Base):
         action = "message_get_many"
         body = {"queue_name": "kitkat",
                 "message_ids": self.msg_ids}
-        req = test_utils.create_request(action, body, self.headers)
+        req = create_req(action, body, self.headers)
 
-        self.protocol.onMessage(req, False)
+        self.protocol.onMessage(req, in_binary)
 
-        resp = json.loads(send_mock.call_args[0][0])
+        resp = loads(send_mock.call_args[0][0])
         self.assertEqual(200, resp['headers']['status'])
         expected_ttls = set(m['ttl'] for m in sample_messages)
         actual_ttls = set(m['ttl'] for m in resp['body']['messages'])
@@ -181,21 +183,23 @@ class MessagesBaseTest(base.V2Base):
         resp = json.loads(send_mock.call_args[0][0])
         self.assertEqual(400, resp['headers']['status'])
 
-    def test_post_single(self):
+    @ddt.data(True, False)
+    def test_post_single(self, in_binary):
         sample_messages = [
             {'body': {'key': 'value'}, 'ttl': 200},
         ]
 
-        self._test_post(sample_messages)
+        self._test_post(sample_messages, in_binary=in_binary)
 
-    def test_post_multiple(self):
+    @ddt.data(True, False)
+    def test_post_multiple(self, in_binary):
         sample_messages = [
             {'body': 239, 'ttl': 100},
             {'body': {'key': 'value'}, 'ttl': 200},
             {'body': [1, 3], 'ttl': 300},
         ]
 
-        self._test_post(sample_messages)
+        self._test_post(sample_messages, in_binary=in_binary)
 
     def test_post_optional_ttl(self):
         messages = [{'body': 239},

zaqar/tests/unit/transport/websocket/v2/test_subscriptions.py

@@ -17,6 +17,7 @@ import json
 import uuid
 
 import mock
+import msgpack
 
 from zaqar.storage import errors as storage_errors
 from zaqar.tests.unit.transport.websocket import base
@@ -26,7 +27,7 @@ from zaqar.transport.websocket import factory
 
 class SubscriptionTest(base.V1_1Base):
 
-    config_file = 'websocket_mongodb.conf'
+    config_file = 'websocket_mongodb_subscriptions.conf'
 
     def setUp(self):
         super(SubscriptionTest, self).setUp()
@@ -222,6 +223,69 @@ class SubscriptionTest(base.V1_1Base):
         self.assertEqual(1, sender.call_count)
         self.assertEqual(response, json.loads(sender.call_args[0][0]))
 
+    def test_subscription_sustainable_notifications_format(self):
+        # NOTE(Eva-i): The websocket subscription's notifications must be
+        # sent in the same format, binary or text, as the format of the
+        # subscription creation request.
+        # This test checks that notifications keep their encoding format, even
+        # if the client suddenly starts sending requests in another format.
+
+        # Create a subscription in binary format
+        action = 'subscription_create'
+        body = {'queue_name': 'kitkat', 'ttl': 600}
+
+        send_mock = mock.patch.object(self.protocol, 'sendMessage')
+        self.addCleanup(send_mock.stop)
+        sender = send_mock.start()
+
+        subscription_factory = factory.NotificationFactory(
+            self.transport.factory)
+        subscription_factory.set_subscription_url('http://localhost:1234/')
+        self.protocol._handler.set_subscription_factory(subscription_factory)
+
+        req = test_utils.create_binary_request(action, body, self.headers)
+        self.protocol.onMessage(req, True)
+        self.assertTrue(self.protocol.notify_in_binary)
+
+        [subscriber] = list(
+            next(
+                self.boot.storage.subscription_controller.list(
+                    'kitkat', self.project_id)))
+        self.addCleanup(
+            self.boot.storage.subscription_controller.delete, 'kitkat',
+            subscriber['id'], project=self.project_id)
+
+        # Send a message in text format
+        webhook_notification_send_mock = mock.patch('requests.post')
+        self.addCleanup(webhook_notification_send_mock.stop)
+        webhook_notification_sender = webhook_notification_send_mock.start()
+
+        action = "message_post"
+        body = {"queue_name": "kitkat",
+                "messages": [{'body': {'status': 'disco queen'}, 'ttl': 60}]}
+        req = test_utils.create_request(action, body, self.headers)
+        self.protocol.onMessage(req, False)
+        self.assertTrue(self.protocol.notify_in_binary)
+
+        # Check that the server responded in text format to the message
+        # creation request
+        message_create_response = json.loads(sender.call_args_list[1][0][0])
+        self.assertEqual(201, message_create_response['headers']['status'])
+
+        # Fetch webhook notification that was intended to arrive to
+        # notification protocol's listen address. Make subscription factory
+        # send it as websocket notification to the client
+        wh_notification = webhook_notification_sender.call_args[1]['data']
+        subscription_factory.send_data(wh_notification, self.protocol.proto_id)
+
+        # Check that the server sent the websocket notification in binary
+        # format
+        self.assertEqual(3, sender.call_count)
+        ws_notification = msgpack.unpackb(sender.call_args_list[2][0][0],
+                                          encoding='utf-8')
+        self.assertEqual({'body': {'status': 'disco queen'}, 'ttl': 60,
+                          'queue_name': 'kitkat'}, ws_notification)
+
     def test_list_returns_503_on_nopoolfound_exception(self):
         sub = self.boot.storage.subscription_controller.create(
             'kitkat', '', 600, {}, project=self.project_id)

zaqar/transport/websocket/factory.py

@@ -13,9 +13,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import uuid
 
 from autobahn.asyncio import websocket
+import msgpack
 
 from zaqar.transport.websocket import protocol
 
@@ -59,7 +61,11 @@ class NotificationFactory(object):
     def send_data(self, data, proto_id):
         instance = self.message_factory._protos.get(proto_id)
         if instance:
-            instance.sendMessage(data, False)
+            # NOTE(Eva-i): incoming data is encoded in JSON, let's convert it
+            # to MsgPack, if notification should be encoded in binary format.
+            if instance.notify_in_binary:
+                data = msgpack.packb(json.loads(data))
+            instance.sendMessage(data, instance.notify_in_binary)
 
     def __call__(self):
         return self.protocol(self)

zaqar/transport/websocket/protocol.py

@@ -16,8 +16,10 @@
 import datetime
 import io
 import json
+import sys
 
 from autobahn.asyncio import websocket
+import msgpack
 from oslo_log import log as logging
 from oslo_utils import timeutils
 import pytz
@@ -35,6 +37,8 @@ except ImportError:
     from email.mime import message
     Message = message.MIMEMessage
 
+from zaqar.i18n import _LI
+
 
 LOG = logging.getLogger(__name__)
 
@@ -60,38 +64,46 @@ class MessagingProtocol(websocket.WebSocketServerProtocol):
         self._loop = loop
         self._authentified = False
         self._auth_app = None
+        self._auth_in_binary = None
         self._deauth_handle = None
+        self.notify_in_binary = None
 
     def onConnect(self, request):
-        print("Client connecting: {0}".format(request.peer))
+        LOG.info(_LI("Client connecting: %s"), request.peer)
 
     def onOpen(self):
-        print("WebSocket connection open.")
+        LOG.info(_LI("WebSocket connection open."))
 
     def onMessage(self, payload, isBinary):
-        if isBinary:
-            # TODO(vkmc): Binary support will be added in the next cycle
-            # For now, we are returning an invalid request response
-            print("Binary message received: {0} bytes".format(len(payload)))
-            body = {'error': 'Schema validation failed.'}
-            resp = self._handler.create_response(400, body)
-            return self._send_response(resp)
+        # Deserialize the request
         try:
-            print("Text message received: {0}".format(payload))
-            payload = json.loads(payload)
-        except ValueError as ex:
-            LOG.exception(ex)
-            body = {'error': str(ex)}
+            if isBinary:
+                payload = msgpack.unpackb(payload, encoding='utf-8')
+            else:
+                payload = json.loads(payload)
+        except Exception:
+            if isBinary:
+                pack_name = 'binary (MessagePack)'
+            else:
+                pack_name = 'text (JSON)'
+            ex_type, ex_value = sys.exc_info()[:2]
+            ex_name = ex_type.__name__
+            msg = 'Can\'t decode {0} request. {1}: {2}'.format(
+                pack_name, ex_name, ex_value)
+            LOG.debug(msg)
+            body = {'error': msg}
             resp = self._handler.create_response(400, body)
-            return self._send_response(resp)
+            return self._send_response(resp, isBinary)
+        # Check if the request is dict
         if not isinstance(payload, dict):
             body = {
-                'error': "Unexpected body type. Expected dict or dict like"
+                'error': 'Unexpected body type. Expected dict or dict like.'
             }
             resp = self._handler.create_response(400, body)
-            return self._send_response(resp)
-
+            return self._send_response(resp, isBinary)
+        # Parse the request
         req = self._handler.create_request(payload)
+        # Validate and process the request
         resp = self._handler.validate_request(payload, req)
         if resp is None:
             if self._auth_strategy and not self._authentified:
@@ -108,17 +120,28 @@ class MessagingProtocol(websocket.WebSocketServerProtocol):
                         body = {'error': 'Not authentified.'}
                         resp = self._handler.create_response(403, body, req)
                 else:
-                    return self._authenticate(payload)
+                    return self._authenticate(payload, isBinary)
             elif payload.get('action') == 'authenticate':
-                return self._authenticate(payload)
+                return self._authenticate(payload, isBinary)
             else:
                 resp = self._handler.process_request(req, self)
-        return self._send_response(resp)
+            if payload.get('action') == 'subscription_create':
+                # NOTE(Eva-i): this will make further websocket
+                # notifications encoded in the same format as the last
+                # successful websocket subscription create request.
+                if resp._headers['status'] == 201:
+                    subscriber = payload['body'].get('subscriber')
+                    # If there is no subscriber, the user has created websocket
+                    # subscription.
+                    if not subscriber:
+                        self.notify_in_binary = isBinary
+        return self._send_response(resp, isBinary)
 
     def onClose(self, wasClean, code, reason):
-        print("WebSocket connection closed: {0}".format(reason))
+        LOG.info(_LI("WebSocket connection closed: %s"), reason)
 
-    def _authenticate(self, payload):
+    def _authenticate(self, payload, in_binary):
+        self._auth_in_binary = in_binary
         self._auth_app = self._auth_strategy(self._auth_start)
         env = self._fake_env.copy()
         env.update(
@@ -150,18 +173,33 @@ class MessagingProtocol(websocket.WebSocketServerProtocol):
         if code != 200:
             body = {'error': 'Authentication failed.'}
             resp = self._handler.create_response(code, body, req)
-            self._send_response(resp)
+            self._send_response(resp, self._auth_in_binary)
         else:
             body = {'message': 'Authentified.'}
             resp = self._handler.create_response(200, body, req)
-            self._send_response(resp)
+            self._send_response(resp, self._auth_in_binary)
 
     def _header_to_env_var(self, key):
         return 'HTTP_%s' % key.replace('-', '_').upper()
 
-    def _send_response(self, resp):
-        resp_json = json.dumps(resp.get_response())
-        self.sendMessage(resp_json, False)
+    def _send_response(self, resp, in_binary):
+        if in_binary:
+            pack_name = 'bin'
+            self.sendMessage(msgpack.packb(resp.get_response()), True)
+        else:
+            pack_name = 'txt'
+            self.sendMessage(json.dumps(resp.get_response()), False)
+        if LOG.isEnabledFor(logging.INFO):
+            api = resp._request._api
+            status = resp._headers['status']
+            action = resp._request._action
+            # Dump to JSON to print body without unicode prefixes on Python 2
+            body = json.dumps(resp._request._body)
+            var_dict = {'api': api, 'pack_name': pack_name, 'status':
+                        status, 'action': action, 'body': body}
+            LOG.info(_LI('Response: API %(api)s %(pack_name)s, %(status)s. '
+                         'Request: action "%(action)s", body %(body)s.'),
+                     var_dict)
 
 
 class NotificationProtocol(asyncio.Protocol):