diff --git a/.travis.yml b/.travis.yml
index ec3bd3f..71bc179 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,9 @@
 sudo: false
 language: python
-python: "3.4"
+python: "3.5"
 cache:
-    pip: true
+    directories:
+        - $HOME/.cache/pip
 
 env:
     matrix:
@@ -10,6 +11,7 @@ env:
         - TOX_ENV=py27
         - TOX_ENV=py33
         - TOX_ENV=py34
+        - TOX_ENV=py35
         - TOX_ENV=pypy
         - TOX_ENV=pypy3
 
@@ -36,7 +38,7 @@ matrix:
           sudo: required
         - env:
              - TOX_ENV=py34
-             - DB=5.6.26
+             - DB=5.6.28
           addons:
               apt:
                  packages:
diff --git a/pymysql/connections.py b/pymysql/connections.py
index 737fb51..3f6702e 100644
--- a/pymysql/connections.py
+++ b/pymysql/connections.py
@@ -525,6 +525,7 @@ class Connection(object):
     """
 
     socket = None
+    _auth_plugin_name = ''
 
     def __init__(self, host=None, user=None, password="",
                  database=None, port=3306, unix_socket=None,
@@ -535,7 +536,7 @@ class Connection(object):
                  compress=None, named_pipe=None, no_delay=None,
                  autocommit=False, db=None, passwd=None, local_infile=False,
                  max_allowed_packet=16*1024*1024, defer_connect=False,
-                 plugin_map={}):
+                 auth_plugin_map={}):
         """
         Establish a connection to the MySQL database. Accepts several
         arguments:
@@ -571,12 +572,11 @@ class Connection(object):
         max_allowed_packet: Max size of packet sent to server in bytes. (default: 16MB)
         defer_connect: Don't explicitly connect on contruction - wait for connect call.
             (default: False)
-        plugin_map: Map of plugin names to a class that processes that plugin. The class
-            will take the Connection object as the argument to the constructor. The class
-            needs an authenticate method taking an authentication packet as an argument.
-            For the dialog plugin, a prompt(echo, prompt) method can be used (if no
-            authenticate method) for returning a string from the user.
-
+        auth_plugin_map: A dict of plugin names to a class that processes that plugin.
+            The class will take the Connection object as the argument to the constructor.
+            The class needs an authenticate method taking an authentication packet as
+            an argument.  For the dialog plugin, a prompt(echo, prompt) method can be used
+            (if no authenticate method) for returning a string from the user. (experimental)
         db: Alias for database. (for compatibility to MySQLdb)
         passwd: Alias for password. (for compatibility to MySQLdb)
         """
@@ -672,7 +672,7 @@ class Connection(object):
         self.sql_mode = sql_mode
         self.init_command = init_command
         self.max_allowed_packet = max_allowed_packet
-        self.plugin_map = plugin_map
+        self._auth_plugin_map = auth_plugin_map
         if defer_connect:
             self.socket = None
         else:
@@ -726,7 +726,6 @@ class Connection(object):
     def autocommit(self, value):
         self.autocommit_mode = bool(value)
         current = self.get_autocommit()
-        self.next_packet = 1
         if value != current:
             self._send_autocommit_mode()
 
@@ -816,7 +815,6 @@ class Connection(object):
                 "You may not close previous cursor.")
         # if DEBUG:
         #     print("DEBUG: sending query:", sql)
-        self.next_packet = 1
         if isinstance(sql, text_type) and not (JYTHON or IRONPYTHON):
             if PY2:
                 sql = sql.encode(self.encoding)
@@ -824,7 +822,6 @@ class Connection(object):
                 sql = sql.encode(self.encoding, 'surrogateescape')
         self._execute_command(COMMAND.COM_QUERY, sql)
         self._affected_rows = self._read_query_result(unbuffered=unbuffered)
-        self.next_packet = 1
         return self._affected_rows
 
     def next_result(self, unbuffered=False):
@@ -892,7 +889,7 @@ class Connection(object):
                 sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
             self.socket = sock
             self._rfile = _makefile(sock, 'rb')
-            self.next_packet = 0
+            self._next_seq_id = 0
 
             self._get_server_information()
             self._request_authentication()
@@ -933,16 +930,16 @@ class Connection(object):
             # So just reraise it.
             raise
 
-    def write_packet(self, data):
+    def write_packet(self, payload):
         """Writes an entire "mysql packet" in its entirety to the network
-        addings its length and sequence number. Intended for use by plugins
-        only.
+        addings its length and sequence number.
         """
-        data = pack_int24(len(data)) + int2byte(self.next_packet) + data
+        # Internal note: when you build packet manualy and calls _write_bytes()
+        # directly, you should set self._next_seq_id properly.
+        data = pack_int24(len(payload)) + int2byte(self._next_seq_id) + payload
         if DEBUG: dump_packet(data)
-
         self._write_bytes(data)
-        self.next_packet = (self.next_packet + 1) % 256
+        self._next_seq_id = (self._next_seq_id + 1) % 256
 
     def _read_packet(self, packet_type=MysqlPacket):
         """Read an entire "mysql packet" in its entirety from the network
@@ -952,8 +949,14 @@ class Connection(object):
         while True:
             packet_header = self._read_bytes(4)
             if DEBUG: dump_packet(packet_header)
+
             btrl, btrh, packet_number = struct.unpack('<HBB', packet_header)
             bytes_to_read = btrl + (btrh << 16)
+            if packet_number != self._next_seq_id:
+                raise err.InternalError("Packet sequence number wrong - got %d expected %d" %
+                    (packet_number, self._next_seq_id))
+            self._next_seq_id = (self._next_seq_id + 1) % 256
+
             recv_data = self._read_bytes(bytes_to_read)
             if DEBUG: dump_packet(recv_data)
             buff += recv_data
@@ -962,13 +965,7 @@ class Connection(object):
                 continue
             if bytes_to_read < MAX_PACKET_LEN:
                 break
-        if packet_number != self.next_packet:
-            pass
-            #TODO: check sequence id
-            #raise err.InternalError("Packet sequence number wrong - got %d expected %d" %
-            #    (packet_number, self.next_packet))
 
-        self.next_packet = (packet_number + 1) % 256
         packet = packet_type(buff, self.encoding)
         packet.check_error()
         return packet
@@ -1027,33 +1024,32 @@ class Connection(object):
         if self._result is not None and self._result.unbuffered_active:
             warnings.warn("Previous unbuffered result was left incomplete")
             self._result._finish_unbuffered_query()
+        self._result = None
 
         if isinstance(sql, text_type):
             sql = sql.encode(self.encoding)
 
-        chunk_size = min(self.max_allowed_packet, len(sql) + 1)  # +1 is for command
+        # +1 is for command
+        chunk_size = min(self.max_allowed_packet, len(sql) + 1)
 
+        # tiny optimization: build first packet manually instead of
+        # calling self..write_packet()
         prelude = struct.pack('<iB', chunk_size, command)
-        self._write_bytes(prelude + sql[:chunk_size-1])
-        if DEBUG: dump_packet(prelude + sql)
+        packet = prelude + sql[:chunk_size-1]
+        self._write_bytes(packet)
+        if DEBUG: dump_packet(packet)
+        self._next_seq_id = 1
 
-        self.next_packet = 1
         if chunk_size < self.max_allowed_packet:
             return
 
-        seq_id = 1
         sql = sql[chunk_size-1:]
         while True:
             chunk_size = min(self.max_allowed_packet, len(sql))
-            prelude = struct.pack('<i', chunk_size)[:3]
-            data = prelude + int2byte(seq_id%256) + sql[:chunk_size]
-            self._write_bytes(data)
-            if DEBUG: dump_packet(data)
+            self.write_packet(sql[:chunk_size])
             sql = sql[chunk_size:]
             if not sql and chunk_size < self.max_allowed_packet:
                 break
-            seq_id += 1
-        self.next_packet = seq_id%256
 
     def _request_authentication(self):
         # https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::HandshakeResponse
@@ -1078,18 +1074,15 @@ class Connection(object):
 
         data = data_init + self.user + b'\0'
 
-        authresp = ''
-        if self.plugin_name == 'mysql_native_password':
+        authresp = b''
+        if self._auth_plugin_name == 'mysql_native_password':
             authresp = _scramble(self.password.encode('latin1'), self.salt)
 
         if self.server_capabilities & CLIENT.PLUGIN_AUTH_LENENC_CLIENT_DATA:
-            data += lenenc_int(len(authresp))
-            data += authresp
+            data += lenenc_int(len(authresp)) + authresp
         elif self.server_capabilities & CLIENT.SECURE_CONNECTION:
-            length = len(authresp)
-            data += struct.pack('B', length)
-            data += authresp
-        else: # pragma: no cover - not testing against servers without secure auth (>=5.0)
+            data += struct.pack('B', len(authresp)) + authresp
+        else:  # pragma: no cover - not testing against servers without secure auth (>=5.0)
             data += authresp + b'\0'
 
         if self.db and self.server_capabilities & CLIENT.CONNECT_WITH_DB:
@@ -1098,15 +1091,16 @@ class Connection(object):
             data += self.db + b'\0'
 
         if self.server_capabilities & CLIENT.PLUGIN_AUTH:
-            data += self.plugin_name.encode('latin1') + b'\0'
+            name = self._auth_plugin_name
+            if isinstance(name, text_type):
+                name = name.encode('ascii')
+            data += name + b'\0'
 
         self.write_packet(data)
-
         auth_packet = self._read_packet()
 
         # if authentication method isn't accepted the first byte
         # will have the octet 254
-
         if auth_packet.is_auth_switch_request():
             # https://dev.mysql.com/doc/internals/en/connection-phase-packets.html#packet-Protocol::AuthSwitchRequest
             auth_packet.read_uint8() # 0xfe packet identifier
@@ -1119,8 +1113,13 @@ class Connection(object):
                 self.write_packet(data)
                 auth_packet = self._read_packet()
 
+        #TODO: ok packet or error packet?
+
+
     def _process_auth(self, plugin_name, auth_packet):
-        plugin_class = self.plugin_map.get(plugin_name)
+        plugin_class = self._auth_plugin_map.get(plugin_name)
+        if not plugin_class:
+            plugin_class = self._auth_plugin_map.get(plugin_name.decode('ascii'))
         if plugin_class:
             try:
                 handler = plugin_class(self)
@@ -1246,18 +1245,13 @@ class Connection(object):
             server_end = data.find(b'\0', i)
             if server_end < 0: # pragma: no cover - very specific upstream bug
                 # not found \0 and last field so take it all
-                self.plugin_name = data[i:].decode('latin1')
+                self._auth_plugin_name = data[i:].decode('latin1')
             else:
-                self.plugin_name = data[i:server_end].decode('latin1')
-        else: # pragma: no cover - not testing against any plugin uncapable servers
-            self.plugin_name = ''
+                self._auth_plugin_name = data[i:server_end].decode('latin1')
 
     def get_server_info(self):
         return self.server_version
 
-    def get_plugin_name(self):
-        return self.plugin_name
-
     Warning = err.Warning
     Error = err.Error
     InterfaceError = err.InterfaceError
@@ -1331,7 +1325,11 @@ class MySQLResult(object):
     def _read_load_local_packet(self, first_packet):
         load_packet = LoadLocalPacketWrapper(first_packet)
         sender = LoadLocalFile(load_packet.filename, self.connection)
-        sender.send_data()
+        try:
+            sender.send_data()
+        except:
+            self.connection._read_packet()  # skip ok packet
+            raise
 
         ok_packet = self.connection._read_packet()
         if not ok_packet.is_ok_packet(): # pragma: no cover - upstream induced protocol error
@@ -1448,27 +1446,20 @@ class LoadLocalFile(object):
         """Send data packets from the local file to the server"""
         if not self.connection.socket:
             raise err.InterfaceError("(0, '')")
+        conn = self.connection
 
-        # sequence id is 2 as we already sent a query packet
-        seq_id = 2
         try:
             with open(self.filename, 'rb') as open_file:
-                chunk_size = self.connection.max_allowed_packet
+                chunk_size = conn.max_allowed_packet
                 packet = b""
 
                 while True:
                     chunk = open_file.read(chunk_size)
                     if not chunk:
                         break
-                    packet = struct.pack('<i', len(chunk))[:3] + int2byte(seq_id)
-                    format_str = '!{0}s'.format(len(chunk))
-                    packet += struct.pack(format_str, chunk)
-                    self.connection._write_bytes(packet)
-                    seq_id = (seq_id + 1) % 256
+                    conn.write_packet(chunk)
         except IOError:
             raise err.OperationalError(1017, "Can't find file '{0}'".format(self.filename))
         finally:
             # send the empty packet to signify we are done sending data
-            packet = struct.pack('<i', 0)[:3] + int2byte(seq_id)
-            self.connection._write_bytes(packet)
-            self.next_packet = (seq_id + 1) % 256
+            conn.write_packet(b'')
diff --git a/pymysql/tests/test_connection.py b/pymysql/tests/test_connection.py
index 9cca817..fac3f04 100644
--- a/pymysql/tests/test_connection.py
+++ b/pymysql/tests/test_connection.py
@@ -40,6 +40,7 @@ class TempUser:
         if self._created:
             self._c.execute("DROP USER %s" % self._user)
 
+
 class TestAuthentication(base.PyMySQLTestCase):
 
     socket_auth = False
@@ -95,7 +96,7 @@ class TestAuthentication(base.PyMySQLTestCase):
 
     def test_plugin(self):
         # Bit of an assumption that the current user is a native password
-        self.assertEqual('mysql_native_password', self.connections[0].get_plugin_name())
+        self.assertEqual('mysql_native_password', self.connections[0]._auth_plugin_name)
 
     @unittest2.skipUnless(socket_auth, "connection to unix_socket required")
     @unittest2.skipIf(socket_found, "socket plugin already installed")
@@ -198,7 +199,7 @@ class TestAuthentication(base.PyMySQLTestCase):
                       self.databases[0]['db'], 'two_questions', 'notverysecret') as u:
             with self.assertRaises(pymysql.err.OperationalError):
                 pymysql.connect(user='pymysql_2q', **self.db)
-            pymysql.connect(user='pymysql_2q', plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
+            pymysql.connect(user='pymysql_2q', auth_plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
 
     @unittest2.skipUnless(socket_auth, "connection to unix_socket required")
     @unittest2.skipIf(three_attempts_found, "three_attempts plugin already installed")
@@ -225,21 +226,21 @@ class TestAuthentication(base.PyMySQLTestCase):
         TestAuthentication.Dialog.fail=True   # fail just once. We've got three attempts after all
         with TempUser(self.connections[0].cursor(), 'pymysql_3a@localhost',
                       self.databases[0]['db'], 'three_attempts', 'stillnotverysecret') as u:
-            pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
-            pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': TestAuthentication.DialogHandler}, **self.db)
+            pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
+            pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': TestAuthentication.DialogHandler}, **self.db)
             with self.assertRaises(pymysql.err.OperationalError):
-                pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': object}, **self.db)
+                pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': object}, **self.db)
 
             with self.assertRaises(pymysql.err.OperationalError):
-                pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': TestAuthentication.DefectiveHandler}, **self.db)
+                pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': TestAuthentication.DefectiveHandler}, **self.db)
             with self.assertRaises(pymysql.err.OperationalError):
-                pymysql.connect(user='pymysql_3a', plugin_map={b'notdialogplugin': TestAuthentication.Dialog}, **self.db)
+                pymysql.connect(user='pymysql_3a', auth_plugin_map={b'notdialogplugin': TestAuthentication.Dialog}, **self.db)
             TestAuthentication.Dialog.m = {b'Password, please:': b'I do not know'}
             with self.assertRaises(pymysql.err.OperationalError):
-                pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
+                pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
             TestAuthentication.Dialog.m = {b'Password, please:': None}
             with self.assertRaises(pymysql.err.OperationalError):
-                pymysql.connect(user='pymysql_3a', plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
+                pymysql.connect(user='pymysql_3a', auth_plugin_map={b'dialog': TestAuthentication.Dialog}, **self.db)
 
     @unittest2.skipUnless(socket_auth, "connection to unix_socket required")
     @unittest2.skipIf(pam_found, "pam plugin already installed")
@@ -285,12 +286,16 @@ class TestAuthentication(base.PyMySQLTestCase):
                 c = pymysql.connect(user=TestAuthentication.osuser, **db)
                 db['password'] = 'very bad guess at password'
                 with self.assertRaises(pymysql.err.OperationalError):
-                    pymysql.connect(user=TestAuthentication.osuser, plugin_map={b'mysql_cleartext_password': TestAuthentication.DefectiveHandler}, **self.db)
+                    pymysql.connect(user=TestAuthentication.osuser,
+                                    auth_plugin_map={b'mysql_cleartext_password': TestAuthentication.DefectiveHandler},
+                                    **self.db)
             except pymysql.OperationalError as e:
                 self.assertEqual(1045, e.args[0])
                 # we had 'bad guess at password' work with pam. Well at least we get a permission denied here
                 with self.assertRaises(pymysql.err.OperationalError):
-                    pymysql.connect(user=TestAuthentication.osuser, plugin_map={b'mysql_cleartext_password': TestAuthentication.DefectiveHandler}, **self.db)
+                    pymysql.connect(user=TestAuthentication.osuser,
+                                    auth_plugin_map={b'mysql_cleartext_password': TestAuthentication.DefectiveHandler},
+                                    **self.db)
         if grants:
             # recreate the user
             cur.execute(grants)
diff --git a/pymysql/tests/test_load_local.py b/pymysql/tests/test_load_local.py
index 1115bb3..601b77c 100644
--- a/pymysql/tests/test_load_local.py
+++ b/pymysql/tests/test_load_local.py
@@ -61,6 +61,7 @@ class TestLoadLocal(base.PyMySQLTestCase):
                 self.assertTrue("Incorrect integer value" in str(w[-1].message))
         finally:
             c.execute("DROP TABLE test_load_local")
+            c.close()
 
 
 if __name__ == "__main__":