diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 00000000..62bca231
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,37 @@
+name: test-run
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    if: ( github.event_name == 'push' ||
+        github.event.pull_request.head.repo.full_name != github.repository ) &&
+        ( github.repository == 'tarantool/test-run' )
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.8-dev]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: display python version
+      run: python -c "import sys; print(sys.version)"
+    - name: setup dependencies
+      run: |
+       sudo apt update -y
+       sudo apt-get -y install lua5.1 luarocks
+       sudo luarocks install luacheck
+    - name: setup python dependencies
+      run: |
+       pip install -r requirements.txt
+       pip install -r requirements-test.txt
+    - name: run static analysis
+      run: |
+       make lint
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index d5c4344d..00000000
--- a/.travis.yml
+++ /dev/null
@@ -1,14 +0,0 @@
-language: python
-python: 2.7
-
-before_install:
-  - sudo apt update -y
-  - sudo apt-get -y install lua5.1 luarocks
-  - sudo luarocks install luacheck
-
-install:
-  - pip install -r requirements.txt
-  - pip install -r requirements-test.txt
-
-script:
-  - make lint
diff --git a/Makefile b/Makefile
index a2143d37..9e8b6f5c 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ default:
 lint: flake8 luacheck
 
 flake8:
-	python2 -m flake8 *.py lib/*.py
+	python -m flake8 *.py lib/*.py
 
 luacheck:
 	luacheck --config .luacheckrc .
diff --git a/dispatcher.py b/dispatcher.py
index 9f9c0443..f878e9a4 100644
--- a/dispatcher.py
+++ b/dispatcher.py
@@ -7,13 +7,42 @@
 import yaml
 
 import multiprocessing
-from multiprocessing.queues import SimpleQueue
 
-import listeners
-import lib
+# SimpleQueue is available from multiprocessing.queues on
+# all Python versions known at the moment of writting the code
+# (up to 3.9).
+#
+# It was additionally exposed directly from the multiprocessing
+# module since Python 3.3 ([1]).
+#
+# However the mandatory argument 'ctx'
+# (see multiprocessing.get_context()) was added to the constructor
+# of SimpleQueue from multiprocessing.queues since Python 3.4
+# ([2]).
+#
+# So we should import SimpleQueue from multiprocessing on
+# Python 3.3+ (and must to do so on Python 3.4+) to uniformly
+# instantiate it (without constructor arguments).
+#
+# [1]: https://bugs.python.org/issue11836
+# [2]: https://bugs.python.org/issue18999
+try:
+    # Python 3.3+
+    from multiprocessing import SimpleQueue
+except ImportError:
+    # Python 2
+    from multiprocessing.queues import SimpleQueue
+
+from lib import Options
 from lib.utils import set_fd_cloexec
 from lib.worker import WorkerTaskResult, WorkerDone
 from lib.colorer import color_stdout
+from listeners import ArtifactsWatcher
+from listeners import FailWatcher
+from listeners import HangWatcher
+from listeners import LogOutputWatcher
+from listeners import OutputWatcher
+from listeners import StatisticsWatcher
 
 
 class TcpPortDispatcher:
@@ -122,30 +151,27 @@ def kill_all_workers(self):
                 pass
 
     def init_listeners(self):
-        args = lib.Options().args
+        args = Options().args
         watch_hang = args.no_output_timeout >= 0 and \
             not args.gdb and \
             not args.gdbserver and \
             not args.lldb and \
             not args.valgrind
-        watch_fail = not lib.Options().args.is_force
-
-        log_output_watcher = listeners.LogOutputWatcher()
-        self.statistics = listeners.StatisticsWatcher(
-            log_output_watcher.get_logfile)
-        self.artifacts = listeners.ArtifactsWatcher(
-            log_output_watcher.get_logfile)
-        output_watcher = listeners.OutputWatcher()
+        watch_fail = not Options().args.is_force
+
+        log_output_watcher = LogOutputWatcher()
+        self.statistics = StatisticsWatcher(log_output_watcher.get_logfile)
+        self.artifacts = ArtifactsWatcher(log_output_watcher.get_logfile)
+        output_watcher = OutputWatcher()
         self.listeners = [self.statistics, log_output_watcher, output_watcher, self.artifacts]
         if watch_fail:
-            self.fail_watcher = listeners.FailWatcher(
-                self.terminate_all_workers)
+            self.fail_watcher = FailWatcher(self.terminate_all_workers)
             self.listeners.append(self.fail_watcher)
         if watch_hang:
             warn_timeout = 60.0 if args.long else 10.0
-            hang_watcher = listeners.HangWatcher(
-                output_watcher.not_done_worker_ids, self.kill_all_workers,
-                warn_timeout, float(args.no_output_timeout))
+            hang_watcher = HangWatcher(output_watcher.not_done_worker_ids,
+                                       self.kill_all_workers, warn_timeout,
+                                       float(args.no_output_timeout))
             self.listeners.append(hang_watcher)
 
     def run_max_workers(self):
@@ -315,8 +341,8 @@ def flush_ready(self, inputs):
         # leave only output listeners in self.listeners
         new_listeners = []
         for listener in self.listeners:
-            if isinstance(listener, (listeners.LogOutputWatcher,
-                                     listeners.OutputWatcher)):
+            if isinstance(listener, (LogOutputWatcher,
+                                     OutputWatcher)):
                 listener.report_at_timeout = False
                 new_listeners.append(listener)
         self.listeners = new_listeners
diff --git a/lib/__init__.py b/lib/__init__.py
index c03a6d86..0dffc40f 100644
--- a/lib/__init__.py
+++ b/lib/__init__.py
@@ -5,7 +5,7 @@
 from lib.options import Options
 from lib.tarantool_server import TarantoolServer
 from lib.unittest_server import UnittestServer
-from utils import warn_unix_sockets_at_start
+from lib.utils import warn_unix_sockets_at_start
 
 
 __all__ = ['Options']
diff --git a/lib/admin_connection.py b/lib/admin_connection.py
index 1af31275..49ac1079 100644
--- a/lib/admin_connection.py
+++ b/lib/admin_connection.py
@@ -24,10 +24,12 @@
 import re
 import sys
 
-from tarantool_connection import TarantoolConnection
-from tarantool_connection import TarantoolPool
-from tarantool_connection import TarantoolAsyncConnection
+from lib.tarantool_connection import TarantoolConnection
+from lib.tarantool_connection import TarantoolPool
+from lib.tarantool_connection import TarantoolAsyncConnection
 
+from lib.utils import bytes_to_str
+from lib.utils import str_to_bytes
 
 ADMIN_SEPARATOR = '\n'
 
@@ -36,13 +38,13 @@ def get_handshake(sock, length=128, max_try=100):
     """
     Correct way to get tarantool handshake
     """
-    result = ""
+    result = b""
     i = 0
     while len(result) != length and i < max_try:
-        result = "%s%s" % (result, sock.recv(length-len(result)))
+        result = b"%s%s" % (result, sock.recv(length-len(result)))
         # max_try counter for tarantool/gh-1362
         i += 1
-    return result
+    return bytes_to_str(result)
 
 
 class AdminPool(TarantoolPool):
@@ -54,19 +56,19 @@ def _new_connection(self):
             # tarantool/gh-1163
             # 1. raise only if handshake is not full
             # 2. be silent on crashes or if it's server.stop() operation
-            print 'Handshake error {\n', handshake, '\n}'
+            print('Handshake error {\n', handshake, '\n}')
             raise RuntimeError('Broken tarantool console handshake')
         return s
 
 
 class ExecMixIn(object):
     def cmd(self, socket, cmd, silent):
-        socket.sendall(cmd)
+        socket.sendall(str_to_bytes(cmd))
 
         bufsiz = 4096
         res = ""
         while True:
-            buf = socket.recv(bufsiz)
+            buf = bytes_to_str(socket.recv(bufsiz))
             if not buf:
                 break
             res = res + buf
diff --git a/lib/app_server.py b/lib/app_server.py
index 00a82b8f..d4675c8a 100644
--- a/lib/app_server.py
+++ b/lib/app_server.py
@@ -21,8 +21,8 @@
 from lib.utils import format_process
 from lib.utils import signame
 from lib.utils import warn_unix_socket
-from test import TestRunGreenlet, TestExecutionError
 from threading import Timer
+from lib.test import TestRunGreenlet, TestExecutionError
 
 
 def timeout_handler(server_process, test_timeout):
@@ -38,8 +38,8 @@ def run_server(execs, cwd, server, logfile, retval):
     timer.start()
     stdout, stderr = server.process.communicate()
     timer.cancel()
-    sys.stdout.write(stdout)
-    with open(logfile, 'a') as f:
+    sys.stdout.write_bytes(stdout)
+    with open(logfile, 'ab') as f:
         f.write(stderr)
     retval['returncode'] = server.process.wait()
     server.process = None
@@ -252,7 +252,7 @@ def is_correct(run):
                     test_suite.ini,
                     params=params,
                     conf_name=conf_name
-                ) for conf_name, params in runs.iteritems()
+                ) for conf_name, params in runs.items()
                     if is_correct(conf_name)])
             else:
                 tests.append(AppTest(test_name,
diff --git a/lib/box_connection.py b/lib/box_connection.py
index 6eb5121c..6a3617a7 100644
--- a/lib/box_connection.py
+++ b/lib/box_connection.py
@@ -25,7 +25,7 @@
 import ctypes
 import socket
 
-from tarantool_connection import TarantoolConnection
+from lib.tarantool_connection import TarantoolConnection
 
 # monkey patch tarantool and msgpack
 from lib.utils import check_libs
@@ -75,11 +75,11 @@ def execute_no_reconnect(self, command, silent=True):
         if not command:
             return
         if not silent:
-            print command
+            print(command)
         cmd = command.replace(SEPARATOR, ' ') + SEPARATOR
         response = self.py_con.call(cmd)
         if not silent:
-            print response
+            print(response)
         return response
 
     def execute(self, command, silent=True):
@@ -88,8 +88,8 @@ def execute(self, command, silent=True):
     def call(self, command, *args):
         if not command:
             return
-        print 'call ', command, args
+        print('call  {} {}'.format(command, args))
         response = self.py_con.call(command, *args)
         result = str(response)
-        print result
+        print(result)
         return result
diff --git a/lib/connpool.py b/lib/connpool.py
index b54dfadf..b80ba584 100644
--- a/lib/connpool.py
+++ b/lib/connpool.py
@@ -10,7 +10,7 @@
 from contextlib import contextmanager
 from functools import wraps
 
-from test import TestRunGreenlet
+from lib.test import TestRunGreenlet
 
 __all__ = ["ConnectionPool", "retry"]
 
@@ -35,9 +35,9 @@ def __init__(self, size, exc_classes=DEFAULT_EXC_CLASSES, keepalive=None):
         self.keepalive = keepalive
         # Exceptions list must be in tuple form to be caught properly
         self.exc_classes = tuple(exc_classes)
-        for i in xrange(size):
+        for i in range(size):
             self.lock.acquire()
-        for i in xrange(size):
+        for i in range(size):
             greenlet = TestRunGreenlet(self._addOne)
             greenlet.start_later(self.SPAWN_FREQUENCY * i)
         if self.keepalive:
@@ -134,7 +134,7 @@ def deco(*args, **kwargs):
             except exc_classes as e:
                 if logger is not None:
                     logger.log(retry_log_level,
-                               retry_log_message.format(f=f.func_name, e=e))
+                               retry_log_message.format(f=f.__name__, e=e))
                 gevent.sleep(interval)
                 failures += 1
                 if max_failures is not None \
@@ -142,6 +142,6 @@ def deco(*args, **kwargs):
                     if logger is not None:
                         logger.log(max_failure_log_level,
                                    max_failure_log_message.format(
-                                       f=f.func_name, e=e))
+                                       f=f.__name__, e=e))
                     raise
     return deco
diff --git a/lib/inspector.py b/lib/inspector.py
index 1d68deaa..9733cc1f 100644
--- a/lib/inspector.py
+++ b/lib/inspector.py
@@ -6,8 +6,10 @@
 from gevent.lock import Semaphore
 from gevent.server import StreamServer
 
+from lib.utils import bytes_to_str
 from lib.utils import find_port
 from lib.utils import prefix_each_line
+from lib.utils import str_to_bytes
 from lib.colorer import color_stdout
 from lib.colorer import color_log
 from lib.colorer import qa_notice
@@ -77,7 +79,7 @@ def readline(socket, delimiter='\n', size=4096):
 
         while data:
             try:
-                data = socket.recv(size)
+                data = bytes_to_str(socket.recv(size))
             except IOError:
                 # catch instance halt connection refused errors
                 data = ''
@@ -119,7 +121,7 @@ def handle(self, socket, addr):
             color_log("DEBUG: test-run's response for [{}]\n{}\n".format(
                 line, prefix_each_line(' | ', result)),
                 schema='test-run command')
-            socket.sendall(result)
+            socket.sendall(str_to_bytes(result))
 
         self.sem.release()
 
diff --git a/lib/preprocessor.py b/lib/preprocessor.py
index 29d6c517..a2c1232b 100644
--- a/lib/preprocessor.py
+++ b/lib/preprocessor.py
@@ -6,12 +6,13 @@
 
 import yaml
 from gevent import socket
-import six
 
 from lib.admin_connection import AdminAsyncConnection
 from lib.colorer import color_log
 from lib.utils import signum
 from lib.utils import signame
+from lib.utils import integer_types
+from lib.utils import string_types
 
 
 class Namespace(object):
@@ -216,7 +217,7 @@ def server_start(self, ctype, sname, opts):
             self.connections[sname] = self.servers[sname].admin
             try:
                 self.connections[sname]('return true', silent=True)
-            except socket.error as e:
+            except socket.error:
                 LuaPreprocessorException(
                     'Can\'t start server {0}'.format(repr(sname)))
         return not crash_occured
@@ -412,9 +413,9 @@ def variable(self, ctype, ref, ret):
         if ctype == 'set':
             self.curcon[0].reconnect()
             result = eval(ret[1:-1], {}, self.environ.__dict__)
-            if isinstance(result, six.integer_types):
+            if isinstance(result, integer_types):
                 cmd = '{0}={1}'.format(ref, result)
-            elif isinstance(result, six.string_types):
+            elif isinstance(result, string_types):
                 cmd = '{0}="{1}"'.format(ref, result)
             else:
                 raise LuaPreprocessorException(
@@ -435,7 +436,7 @@ def stop_nondefault(self, signal=signal.SIGTERM):
                                                 names), schema='info')
         if sys.stdout.__class__.__name__ == 'FilteredStream':
             sys.stdout.clear_all_filters()
-        for k, v in self.servers.iteritems():
+        for k, v in self.servers.items():
             # don't stop the default server
             if k == 'default':
                 continue
@@ -448,7 +449,7 @@ def cleanup_nondefault(self):
         names = [k for k in self.servers.keys() if k != 'default']
         color_log('DEBUG: Cleanup non-default servers: {}\n'.format(names),
                   schema='info')
-        for k, v in self.servers.iteritems():
+        for k, v in self.servers.items():
             # don't cleanup the default server
             if k == 'default':
                 continue
diff --git a/lib/pytap13.py b/lib/pytap13.py
index 295a0d15..5aef4313 100644
--- a/lib/pytap13.py
+++ b/lib/pytap13.py
@@ -17,12 +17,16 @@
 # Author: Josef Skladanka <jskladan@redhat.com>
 
 import re
+
 try:
-    from CStringIO import StringIO
-except ImportError:
+    # Python 2
     from StringIO import StringIO
+except ImportError:
+    # Python 3
+    from io import StringIO
 
 import yaml
+from lib.utils import string_types
 
 
 RE_VERSION = re.compile(r"^\s*TAP version 13\s*$")
@@ -173,7 +177,7 @@ def _parse(self, source):
             self.tests.append(Test('not ok', len(self.tests), comment=comment))
 
     def parse(self, source):
-        if isinstance(source, (str, unicode)):
+        if isinstance(source, string_types):
             self._parse(StringIO(source))
         elif hasattr(source, "__iter__"):
             self._parse(source)
diff --git a/lib/server.py b/lib/server.py
index c699997a..d13aa024 100644
--- a/lib/server.py
+++ b/lib/server.py
@@ -2,6 +2,7 @@
 import os
 import shutil
 from itertools import product
+
 from lib.server_mixins import ValgrindMixin
 from lib.server_mixins import GdbMixin
 from lib.server_mixins import GdbServerMixin
diff --git a/lib/server_mixins.py b/lib/server_mixins.py
index 44da01fe..b2ba8a69 100644
--- a/lib/server_mixins.py
+++ b/lib/server_mixins.py
@@ -1,11 +1,13 @@
 import os
 import glob
 import shlex
+from six.moves import shlex_quote
+
 from lib.utils import find_in_path
 from lib.utils import print_tail_n
 from lib.utils import non_empty_valgrind_logs
-from lib.colorer import color_stdout, color_log
-from six.moves import shlex_quote
+from lib.colorer import color_log
+from lib.colorer import color_stdout
 
 
 def shlex_join(strings):
diff --git a/lib/tarantool_connection.py b/lib/tarantool_connection.py
index 019ed990..b246d4f4 100644
--- a/lib/tarantool_connection.py
+++ b/lib/tarantool_connection.py
@@ -30,10 +30,10 @@
 import gevent
 from gevent import socket as gsocket
 
-from connpool import ConnectionPool
-from test import TestRunGreenlet
-from utils import warn_unix_socket
-from utils import set_fd_cloexec
+from lib.connpool import ConnectionPool
+from lib.test import TestRunGreenlet
+from lib.utils import warn_unix_socket
+from lib.utils import set_fd_cloexec
 
 
 class TarantoolPool(ConnectionPool):
@@ -146,7 +146,7 @@ def opt_reconnect(self):
         """
         try:
             if not self.is_connected or self.socket.recv(
-                    1, socket.MSG_DONTWAIT | socket.MSG_PEEK) == '':
+                    1, socket.MSG_DONTWAIT | socket.MSG_PEEK) == b'':
                 self.reconnect()
         except socket.error as e:
             if e.errno == errno.EAGAIN:
diff --git a/lib/tarantool_server.py b/lib/tarantool_server.py
index 4dc640a6..f611dbaf 100644
--- a/lib/tarantool_server.py
+++ b/lib/tarantool_server.py
@@ -19,9 +19,11 @@
 from threading import Timer
 
 try:
-    from cStringIO import StringIO
-except ImportError:
+    # Python 2
     from StringIO import StringIO
+except ImportError:
+    # Python 3
+    from io import StringIO
 
 from lib.admin_connection import AdminConnection, AdminAsyncConnection
 from lib.box_connection import BoxConnection
@@ -33,6 +35,7 @@
 from lib.server import Server
 from lib.server import DEFAULT_SNAPSHOT_NAME
 from lib.test import Test
+from lib.utils import bytes_to_str
 from lib.utils import find_port
 from lib.utils import extract_schema_from_snapshot
 from lib.utils import format_process
@@ -40,7 +43,7 @@
 from lib.utils import signame
 from lib.utils import warn_unix_socket
 from lib.utils import prefix_each_line
-from test import TestRunGreenlet, TestExecutionError
+from lib.test import TestRunGreenlet, TestExecutionError
 
 
 def save_join(green_obj, timeout=None):
@@ -396,8 +399,10 @@ class PythonTest(Test):
 
     def execute(self, server):
         super(PythonTest, self).execute(server)
-        execfile(self.name, dict(locals(), test_run_current_test=self,
-                                 **server.__dict__))
+        new_globals = dict(locals(), test_run_current_test=self, **server.__dict__)
+        with open(self.name) as f:
+            code = compile(f.read(), self.name, 'exec')
+            exec(code, new_globals)
         # crash was detected (possibly on non-default server)
         if server.current_test.is_crash_reported:
             raise TestExecutionError
@@ -573,7 +578,7 @@ def _iproto(self, port):
     @property
     def log_des(self):
         if not hasattr(self, '_log_des'):
-            self._log_des = open(self.logfile, 'a')
+            self._log_des = open(self.logfile, 'ab')
         return self._log_des
 
     @log_des.deleter
@@ -659,7 +664,7 @@ def __del__(self):
     @classmethod
     def version(cls):
         p = subprocess.Popen([cls.binary, "--version"], stdout=subprocess.PIPE)
-        version = p.stdout.read().rstrip()
+        version = bytes_to_str(p.stdout.read()).rstrip()
         p.wait()
         return version
 
@@ -759,7 +764,7 @@ def deploy(self, silent=True, **kwargs):
     def copy_files(self):
         if self.script:
             shutil.copy(self.script, self.script_dst)
-            os.chmod(self.script_dst, 0777)
+            os.chmod(self.script_dst, 0o777)
         if self.lua_libs:
             for i in self.lua_libs:
                 source = os.path.join(self.testdir, i)
@@ -1153,15 +1158,15 @@ def read_pidfile(self):
     def test_option_get(self, option_list_str, silent=False):
         args = [self.binary] + shlex.split(option_list_str)
         if not silent:
-            print " ".join([os.path.basename(self.binary)] + args[1:])
+            print(" ".join([os.path.basename(self.binary)] + args[1:]))
         output = subprocess.Popen(args,
                                   cwd=self.vardir,
                                   stdout=subprocess.PIPE,
                                   stderr=subprocess.STDOUT).stdout.read()
-        return output
+        return bytes_to_str(output)
 
     def test_option(self, option_list_str):
-        print self.test_option_get(option_list_str)
+        print(self.test_option_get(option_list_str))
 
     @staticmethod
     def find_tests(test_suite, suite_path):
diff --git a/lib/test.py b/lib/test.py
index ad22243d..0f002802 100644
--- a/lib/test.py
+++ b/lib/test.py
@@ -2,25 +2,22 @@
 import gevent
 import os
 import pprint
-import pytap13
 import re
 import shutil
 import sys
 import traceback
 from functools import partial
 from hashlib import md5
-from utils import safe_makedirs
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
-
-import lib
+from lib import Options
 from lib.colorer import color_stdout
+from lib.utils import assert_bytes
 from lib.utils import non_empty_valgrind_logs
 from lib.utils import print_tail_n
 from lib.utils import print_unidiff as utils_print_unidiff
+from lib.utils import safe_makedirs
+from lib.utils import str_to_bytes
+from lib import pytap13
 
 
 class TestExecutionError(OSError):
@@ -46,21 +43,17 @@ def __repr__(self):
 class FilteredStream:
     """Helper class to filter .result file output"""
     def __init__(self, filename):
-        #
-        # always open the output stream in line-buffered mode,
-        # to see partial results of a failed test
-        #
-        self.stream = open(filename, "w+", 1)
+        self.stream = open(filename, "wb+")
         self.filters = []
         self.inspector = None
 
-    def write(self, fragment):
-        """Apply all filters, then write result to the undelrying stream.
-        Do line-oriented filtering: the fragment doesn't have to represent
-        just one line."""
-        fragment_stream = StringIO(fragment)
+    def write_bytes(self, fragment):
+        """ The same as ``write()``, but accepts ``<bytes>`` as
+            input.
+        """
+        assert_bytes(fragment)
         skipped = False
-        for line in fragment_stream:
+        for line in fragment.splitlines(True):
             original_len = len(line.strip())
             for pattern, replacement in self.filters:
                 line = re.sub(pattern, replacement, line)
@@ -71,8 +64,20 @@ def write(self, fragment):
             if not skipped:
                 self.stream.write(line)
 
+    def write(self, fragment):
+        """ Apply all filters, then write result to the underlying
+            stream.
+
+            Do line-oriented filtering: the fragment doesn't have
+            to represent just one line.
+
+            Accepts ``<str>`` as input, just like the standard
+            ``sys.stdout.write()``.
+        """
+        self.write_bytes(str_to_bytes(fragment))
+
     def push_filter(self, pattern, replacement):
-        self.filters.append([pattern, replacement])
+        self.filters.append([str_to_bytes(pattern), str_to_bytes(replacement)])
 
     def pop_filter(self):
         self.filters.pop()
@@ -173,7 +178,10 @@ def run(self, server):
             if os.path.exists(self.skip_cond):
                 sys.stdout = FilteredStream(self.tmp_result)
                 stdout_fileno = sys.stdout.stream.fileno()
-                execfile(self.skip_cond, dict(locals(), **server.__dict__))
+                new_globals = dict(locals(), **server.__dict__)
+                with open(self.skip_cond, 'r') as f:
+                    code = compile(f.read(), self.skip_cond, 'exec')
+                    exec(code, new_globals)
                 sys.stdout.close()
                 sys.stdout = save_stdout
             if not self.skip:
@@ -208,7 +216,7 @@ def run(self, server):
                 self.is_equal_result = filecmp.cmp(self.result,
                                                    self.tmp_result)
             elif self.is_executed_ok:
-                if lib.Options().args.is_verbose:
+                if Options().args.is_verbose:
                     color_stdout('\n')
                     with open(self.tmp_result, 'r') as f:
                         color_stdout(f.read(), schema='log')
@@ -241,7 +249,7 @@ def run(self, server):
               not self.is_equal_result and
               not os.path.isfile(self.result) and
               not is_tap and
-              lib.Options().args.update_result):
+              Options().args.update_result):
             shutil.copy(self.tmp_result, self.result)
             short_status = 'new'
             color_stdout("[ new ]\n", schema='test_new')
@@ -249,7 +257,7 @@ def run(self, server):
               not self.is_equal_result and
               os.path.isfile(self.result) and
               not is_tap and
-              lib.Options().args.update_result):
+              Options().args.update_result):
             shutil.copy(self.tmp_result, self.result)
             short_status = 'updated'
             color_stdout("[ updated ]\n", schema='test_new')
@@ -343,7 +351,7 @@ def check_tap_output(self):
                          schema='error')
             color_stdout('\nNo result file (%s) found.\n' % self.result,
                          schema='error')
-            if not lib.Options().args.update_result:
+            if not Options().args.update_result:
                 msg = 'Run the test with --update-result option to write the new result file.\n'
                 color_stdout(msg, schema='error')
             self.is_crash_reported = True
diff --git a/lib/test_suite.py b/lib/test_suite.py
index 91f8088b..67cdadff 100644
--- a/lib/test_suite.py
+++ b/lib/test_suite.py
@@ -1,9 +1,16 @@
-import ConfigParser
+try:
+    # Python 2
+    import ConfigParser as configparser
+except ImportError:
+    # Python 3
+    import configparser
+
 import json
 import os
 import re
+import sys
 
-import lib
+from lib import Options
 from lib.app_server import AppServer
 from lib.colorer import color_stdout
 from lib.inspector import TarantoolInspector
@@ -90,7 +97,11 @@ def __init__(self, suite_path, args):
             raise RuntimeError("Suite %s doesn't exist" % repr(suite_path))
 
         # read the suite config
-        config = ConfigParser.ConfigParser()
+        parser_kwargs = dict()
+        if sys.version_info[0] == 3:
+            parser_kwargs['inline_comment_prefixes'] = (';',)
+            parser_kwargs['strict'] = True
+        config = configparser.ConfigParser(**parser_kwargs)
         config.read(os.path.join(suite_path, "suite.ini"))
         self.ini.update(dict(config.items("default")))
         self.ini.update(self.args.__dict__)
@@ -153,7 +164,7 @@ def collect_tests(self):
         else:
             raise ValueError('Cannot collect tests of unknown type')
 
-        if not lib.Options().args.reproduce:
+        if not Options().args.reproduce:
             color_stdout("Collecting tests in ", schema='ts_text')
             color_stdout(
                 '%s (Found %s tests)' % (
@@ -196,7 +207,7 @@ def gen_server(self):
         try:
             return Server(self.ini, test_suite=self)
         except Exception as e:
-            print e
+            print(e)
             raise RuntimeError("Unknown server: core = {0}".format(
                                self.ini["core"]))
 
@@ -265,7 +276,7 @@ def run_test(self, test, server, inspector):
             result_checksum = None
 
         # cleanup only if test passed or if --force mode enabled
-        if lib.Options().args.is_force or short_status == 'pass':
+        if Options().args.is_force or short_status == 'pass':
             inspector.cleanup_nondefault()
 
         return short_status, result_checksum
diff --git a/lib/unittest_server.py b/lib/unittest_server.py
index a7cc20e5..4df8f0b0 100644
--- a/lib/unittest_server.py
+++ b/lib/unittest_server.py
@@ -16,7 +16,7 @@ def execute(self, server):
         server.current_test = self
         execs = server.prepare_args()
         proc = Popen(execs, cwd=server.vardir, stdout=PIPE, stderr=STDOUT)
-        sys.stdout.write(proc.communicate()[0])
+        sys.stdout.write_bytes(proc.communicate()[0])
 
 
 class UnittestServer(Server):
@@ -48,7 +48,7 @@ def binary(self):
     def prepare_args(self, args=[]):
         executable_path = os.path.join(self.builddir, "test",
                                        self.current_test.name)
-        return [executable_path] + args
+        return [os.path.abspath(executable_path)] + args
 
     def deploy(self, vardir=None, silent=True, wait=True):
         self.vardir = vardir
diff --git a/lib/utils.py b/lib/utils.py
index 2fb12ed9..a92db07c 100644
--- a/lib/utils.py
+++ b/lib/utils.py
@@ -1,6 +1,5 @@
 import os
 import sys
-import six
 import collections
 import signal
 import random
@@ -21,6 +20,17 @@
 
 UNIX_SOCKET_LEN_LIMIT = 107
 
+# Useful for very coarse version differentiation.
+PY3 = sys.version_info[0] == 3
+PY2 = sys.version_info[0] == 2
+
+if PY3:
+    string_types = str,
+    integer_types = int,
+else:
+    string_types = basestring,      # noqa: F821
+    integer_types = (int, long)     # noqa: F821
+
 
 def check_libs():
     deps = [
@@ -68,7 +78,7 @@ def check_port(port, rais=True, ipv4=True, ipv6=True):
     connections (UNIX Sockets in case of file path). False -- otherwise.
     """
     try:
-        if isinstance(port, (int, long)):
+        if isinstance(port, integer_types):
             if ipv4:
                 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                 sock.bind(('127.0.0.1', port))
@@ -139,22 +149,22 @@ def find_in_path(name):
 
 
 def signame(signal):
-    if isinstance(signal, six.integer_types):
+    if isinstance(signal, integer_types):
         return SIGNAMES[signal]
     if Signals and isinstance(signal, Signals):
         return SIGNAMES[int(signal)]
-    if isinstance(signal, six.string_types):
+    if isinstance(signal, string_types):
         return signal
     raise TypeError('signame(): signal argument of unexpected type: {}'.format(
                     str(type(signal))))
 
 
 def signum(signal):
-    if isinstance(signal, six.integer_types):
+    if isinstance(signal, integer_types):
         return signal
     if Signals and isinstance(signal, Signals):
         return int(signal)
-    if isinstance(signal, six.string_types):
+    if isinstance(signal, string_types):
         if not signal.startswith('SIG'):
             signal = 'SIG' + signal
         return SIGNUMS[signal]
@@ -303,3 +313,41 @@ def extract_schema_from_snapshot(snapshot_path):
             if res[0] == 'version':
                 return res
     return None
+
+
+def assert_bytes(b):
+    """ Ensure given value is <bytes>.
+    """
+    if type(b) != bytes:
+        raise ValueError('Internal error: expected {}, got {}: {}'.format(
+            str(bytes), str(type(b)), repr(b)))
+
+
+def assert_str(s):
+    """ Ensure given value is <str>.
+    """
+    if type(s) != str:
+        raise ValueError('Internal error: expected {}, got {}: {}'.format(
+            str(str), str(type(s)), repr(s)))
+
+
+def bytes_to_str(b):
+    """ Convert <bytes> to <str>.
+
+        No-op on Python 2.
+    """
+    assert_bytes(b)
+    if PY2:
+        return b
+    return b.decode('utf-8')
+
+
+def str_to_bytes(s):
+    """ Convert <str> to <bytes>.
+
+        No-op on Python 2.
+    """
+    assert_str(s)
+    if PY2:
+        return s
+    return s.encode('utf-8')
diff --git a/lib/worker.py b/lib/worker.py
index a8643fe8..9ed9b812 100644
--- a/lib/worker.py
+++ b/lib/worker.py
@@ -7,7 +7,7 @@
 import yaml
 from datetime import datetime
 
-import lib
+from lib import Options
 from lib.colorer import color_log
 from lib.colorer import color_stdout
 from lib.tarantool_server import TarantoolServer
@@ -20,13 +20,13 @@
 
 
 def find_suites():
-    suite_names = lib.Options().args.suites
+    suite_names = Options().args.suites
     if suite_names == []:
         for root, dirs, names in os.walk(os.getcwd(), followlinks=True):
             if "suite.ini" in names:
                 suite_names.append(os.path.basename(root))
 
-    suites = [TestSuite(suite_name, lib.Options().args)
+    suites = [TestSuite(suite_name, Options().args)
               for suite_name in sorted(suite_names)]
     return suites
 
@@ -48,7 +48,7 @@ def parse_reproduce_file(filepath):
 
 
 def get_reproduce_file(worker_name):
-    main_vardir = os.path.realpath(lib.Options().args.vardir)
+    main_vardir = os.path.realpath(Options().args.vardir)
     reproduce_dir = os.path.join(main_vardir, 'reproduce')
     return os.path.join(reproduce_dir, '%s.list.yaml' % worker_name)
 
@@ -100,7 +100,7 @@ def reproduce_task_groups(task_groups):
     this group as in the reproduce file.
     """
     found_keys = []
-    reproduce = parse_reproduce_file(lib.Options().args.reproduce)
+    reproduce = parse_reproduce_file(Options().args.reproduce)
     if not reproduce:
         raise ValueError('[reproduce] Tests list cannot be empty')
     for i, task_id in enumerate(reproduce):
@@ -362,7 +362,7 @@ def run_loop(self, task_queue, result_queue):
 
             result_queue.put(self.wrap_result(task_id, short_status, result_checksum))
             if short_status == 'fail':
-                if lib.Options().args.is_force:
+                if Options().args.is_force:
                     self.restart_server()
                     color_stdout(
                         'Worker "%s" got failed test; restarted the server\n'
diff --git a/listeners.py b/listeners.py
index 54f8dddc..b6a9b79b 100644
--- a/listeners.py
+++ b/listeners.py
@@ -3,7 +3,7 @@
 import yaml
 import shutil
 
-import lib
+from lib import Options
 from lib.colorer import color_stdout
 from lib.colorer import decolor
 from lib.worker import WorkerCurrentTask
@@ -13,6 +13,8 @@
 from lib.worker import get_reproduce_file
 from lib.utils import prefix_each_line
 from lib.utils import safe_makedirs
+from lib.utils import print_tail_n
+from lib.utils import print_unidiff
 
 
 class BaseWatcher(object):
@@ -69,7 +71,7 @@ def print_statistics(self):
             color_stdout('# reproduce file: %s\n' % reproduce_file_path)
             if show_reproduce_content:
                 color_stdout("---\n", schema='separator')
-                lib.utils.print_tail_n(reproduce_file_path)
+                print_tail_n(reproduce_file_path)
                 color_stdout("...\n", schema='separator')
 
         return True
@@ -97,7 +99,7 @@ def save_artifacts(self):
         if not self.failed_workers:
             return
 
-        vardir = lib.Options().args.vardir
+        vardir = Options().args.vardir
         artifacts_dir = os.path.join(vardir, 'artifacts')
         artifacts_log_dir = os.path.join(artifacts_dir, 'log')
         artifacts_reproduce_dir = os.path.join(artifacts_dir, 'reproduce')
@@ -124,7 +126,7 @@ def save_artifacts(self):
 class LogOutputWatcher(BaseWatcher):
     def __init__(self):
         self.fds = dict()
-        self.logdir = os.path.join(lib.Options().args.vardir, 'log')
+        self.logdir = os.path.join(Options().args.vardir, 'log')
         try:
             os.makedirs(self.logdir)
         except OSError:
@@ -205,7 +207,7 @@ def process_result(self, obj):
             return
 
         # Skip color_log() events if --debug is not passed.
-        if obj.log_only and not lib.Options().args.debug:
+        if obj.log_only and not Options().args.debug:
             return
 
         # Prepend color_log() messages with a timestamp.
@@ -267,7 +269,7 @@ def process_result(self, obj):
             return
 
         # Skip color_log() events if --debug is not passed.
-        if obj.log_only and not lib.Options().args.debug:
+        if obj.log_only and not Options().args.debug:
             return
 
         self.warned_seconds_ago = 0.0
@@ -291,7 +293,7 @@ def process_timeout(self, delta_seconds):
             schema=color_schema)
 
         hung_tasks = [task for worker_id, task
-                      in self.worker_current_task.iteritems()
+                      in self.worker_current_task.items()
                       if worker_id in worker_ids]
         for task in hung_tasks:
             result_file = task.task_tmp_result
@@ -313,7 +315,7 @@ def process_timeout(self, delta_seconds):
         for task in hung_tasks:
             color_stdout("Test hung! Result content mismatch:\n",
                          schema='error')
-            lib.utils.print_unidiff(task.task_result, task.task_tmp_result)
+            print_unidiff(task.task_result, task.task_tmp_result)
         color_stdout('\n[Main process] No output from workers. '
                      'It seems that we hang. Send SIGKILL to workers; '
                      'exiting...\n', schema='error')
diff --git a/requirements.txt b/requirements.txt
index a1c72dcb..365d1b1f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 PyYAML==5.1
 argparse==1.1
 msgpack-python==0.4.6
-gevent==1.1b5
+gevent==21.1.2
 six>=1.8.0
diff --git a/test-run.py b/test-run.py
index d63f5ed8..0b90494e 100755
--- a/test-run.py
+++ b/test-run.py
@@ -1,7 +1,6 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 """Tarantool regression test suite front-end."""
 
-
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
@@ -54,14 +53,17 @@
 import sys
 import time
 
-import lib
-import lib.worker
-
-from dispatcher import Dispatcher
+from lib import Options
 from lib.colorer import color_stdout
+from lib.utils import print_tail_n
+from lib.utils import PY3
+from lib.worker import get_task_groups
+from lib.worker import get_reproduce_file
+from lib.worker import reproduce_task_groups
+from lib.worker import print_greetings
+from dispatcher import Dispatcher
 from listeners import HangError
 
-
 EXIT_SUCCESS = 0
 EXIT_HANG = 1
 EXIT_INTERRUPTED = 2
@@ -73,7 +75,7 @@
 def main_loop_parallel():
     color_stdout("Started {0}\n".format(" ".join(sys.argv)), schema='tr_text')
 
-    args = lib.Options().args
+    args = Options().args
     jobs = args.jobs
     if jobs < 1:
         # faster result I got was with 2 * cpu_count
@@ -94,16 +96,16 @@ def main_loop_parallel():
                  format(args.no_output_timeout), schema='tr_text')
     color_stdout("\n", schema='tr_text')
 
-    task_groups = lib.worker.get_task_groups()
-    if lib.Options().args.reproduce:
-        task_groups = lib.worker.reproduce_task_groups(task_groups)
+    task_groups = get_task_groups()
+    if Options().args.reproduce:
+        task_groups = reproduce_task_groups(task_groups)
         jobs = 1
         randomize = False
 
     dispatcher = Dispatcher(task_groups, jobs, randomize)
     dispatcher.start()
 
-    lib.worker.print_greetings()
+    print_greetings()
 
     color_stdout("\n", '=' * 86, "\n", schema='separator')
     color_stdout("WORKR".ljust(6),     schema='t_name')
@@ -113,7 +115,7 @@ def main_loop_parallel():
     color_stdout('-' * 81, "\n",       schema='separator')
 
     try:
-        is_force = lib.Options().args.is_force
+        is_force = Options().args.is_force
         dispatcher.wait()
         dispatcher.wait_processes()
         color_stdout('-' * 81, "\n", schema='separator')
@@ -152,8 +154,8 @@ def main_parallel():
 
 def main_loop_consistent(failed_test_ids):
     # find and prepare all tasks/groups, print information
-    task_groups = lib.worker.get_task_groups().items()
-    lib.worker.print_greetings()
+    task_groups = get_task_groups().items()
+    print_greetings()
 
     for name, task_group in task_groups:
         # print information about current test suite
@@ -173,15 +175,15 @@ def main_loop_consistent(failed_test_ids):
             short_status = worker.run_task(task_id)
             if short_status == 'fail':
                 reproduce_file_path = \
-                    lib.worker.get_reproduce_file(worker.name)
+                    get_reproduce_file(worker.name)
                 color_stdout('Reproduce file %s\n' %
                              reproduce_file_path, schema='error')
                 if show_reproduce_content:
                     color_stdout("---\n", schema='separator')
-                    lib.utils.print_tail_n(reproduce_file_path)
+                    print_tail_n(reproduce_file_path)
                     color_stdout("...\n", schema='separator')
                 failed_test_ids.append(task_id)
-                if not lib.Options().args.is_force:
+                if not Options().args.is_force:
                     worker.stop_server(cleanup=False)
                     return
 
@@ -203,11 +205,11 @@ def main_consistent():
     except RuntimeError as e:
         color_stdout("\nFatal error: %s. Execution aborted.\n" % e,
                      schema='error')
-        if lib.Options().args.gdb:
+        if Options().args.gdb:
             time.sleep(100)
         return -1
 
-    if failed_test_ids and lib.Options().args.is_force:
+    if failed_test_ids and Options().args.is_force:
         color_stdout("\n===== %d tests failed:\n" % len(failed_test_ids),
                      schema='error')
         for test_id in failed_test_ids:
@@ -217,14 +219,61 @@ def main_consistent():
 
 
 if __name__ == "__main__":
+    # In Python 3 start method 'spawn' in multiprocessing module becomes
+    # default on Mac OS.
+    #
+    # The 'spawn' method causes re-execution of some code, which is already
+    # executed in the main process. At least it is seen on the
+    # lib/__init__.py code, which removes the 'var' directory. Some other
+    # code may have side effects too, it requires investigation.
+    #
+    # The method also requires object serialization that doesn't work when
+    # objects use lambdas, whose for example used in class TestSuite
+    # (lib/test_suite.py).
+    #
+    # The latter problem is easy to fix, but the former looks more
+    # fundamental. So we stick to the 'fork' method now.
+    if PY3:
+        multiprocessing.set_start_method('fork')
+
+    # test-run assumes that text file streams are UTF-8 (as
+    # contrary to ASCII) on Python 3. It is necessary to process
+    # non ASCII symbols in test files, result files and so on.
+    #
+    # Default text file stream encoding depends on a system
+    # locale with exception for the POSIX locale (C locale): in
+    # this case UTF-8 is used (see PEP-0540). Sadly, this
+    # behaviour is in effect since Python 3.7.
+    #
+    # We want to achieve the same behaviour on lower Python
+    # versions, at least on 3.6.8, which is provided by CentOS 7
+    # and CentOS 8.
+    #
+    # So we hack the open() builtin.
+    #
+    # https://stackoverflow.com/a/53347548/1598057
+    if PY3 and sys.version_info[0:2] < (3, 7):
+        std_open = __builtins__.open
+
+        def open_as_utf8(*args, **kwargs):
+            if len(args) >= 2:
+                mode = args[1]
+            else:
+                mode = kwargs.get('mode', '')
+            if 'b' not in mode:
+                kwargs.setdefault('encoding', 'utf-8')
+            return std_open(*args, **kwargs)
+
+        __builtins__.open = open_as_utf8
+
     # don't sure why, but it values 1 or 2 gives 1.5x speedup for parallel
     # test-run (and almost doesn't affect consistent test-run)
     os.environ['OMP_NUM_THREADS'] = '2'
 
     status = 0
 
-    force_parallel = bool(lib.Options().args.reproduce)
-    if not force_parallel and lib.Options().args.jobs == -1:
+    force_parallel = bool(Options().args.reproduce)
+    if not force_parallel and Options().args.jobs == -1:
         status = main_consistent()
     else:
         status = main_parallel()