ClickHouse/tests/clickhouse-test

#!/usr/bin/env python3

import shutil
import sys
import os
import os.path
import signal
import re
import json
import copy
import traceback

from argparse import ArgumentParser
from typing import Tuple, Union, Optional, TextIO
import shlex
import subprocess
from subprocess import Popen
from subprocess import PIPE
from subprocess import CalledProcessError
from subprocess import TimeoutExpired
from datetime import datetime
from time import time, sleep
from errno import ESRCH

try:
    import termcolor
except ImportError:
    termcolor = None

import random
import string
import multiprocessing
import socket
from contextlib import closing

USE_JINJA = True
try:
    import jinja2
except ImportError:
    USE_JINJA = False
    print('WARNING: jinja2 not installed! Template tests will be skipped.')

DISTRIBUTED_DDL_TIMEOUT_MSG = "is executing longer than distributed_ddl_task_timeout"

MESSAGES_TO_RETRY = [
    "DB::Exception: ZooKeeper session has been expired",
    "DB::Exception: Connection loss",
    "Coordination::Exception: Session expired",
    "Coordination::Exception: Connection loss",
    "Coordination::Exception: Operation timeout",
    "DB::Exception: Operation timeout",
    "Operation timed out",
    "ConnectionPoolWithFailover: Connection failed at try",
    "DB::Exception: New table appeared in database being dropped or detached. Try again",
    "is already started to be removing by another replica right now",
    "Shutdown is called for table", # It happens in SYSTEM SYNC REPLICA query if session with ZooKeeper is being reinitialized.
    DISTRIBUTED_DDL_TIMEOUT_MSG  # FIXME
]

MAX_RETRIES = 3

TEST_FILE_EXTENSIONS = ['.sql', '.sql.j2', '.sh', '.py', '.expect']

class Terminated(KeyboardInterrupt):
    pass

def signal_handler(sig, frame):
    raise Terminated(f'Terminated with {sig} signal')

def stop_tests():
    global stop_tests_triggered_lock
    global stop_tests_triggered

    with stop_tests_triggered_lock:
        if not stop_tests_triggered.is_set():
            stop_tests_triggered.set()

            # send signal to all processes in group to avoid hung check triggering
            # (to avoid terminating clickhouse-test itself, the signal should be ignored)
            signal.signal(signal.SIGTERM, signal.SIG_IGN)
            os.killpg(os.getpgid(os.getpid()), signal.SIGTERM)
            signal.signal(signal.SIGTERM, signal.SIG_DFL)

def json_minify(string):
    """
    Removes all js-style comments from json string. Allows to have comments in skip_list.json.
    The code was taken from https://github.com/getify/JSON.minify/tree/python under the MIT license.
    """

    tokenizer = re.compile(r'"|(/\*)|(\*/)|(//)|\n|\r')
    end_slashes_re = re.compile(r'(\\)*$')

    in_string = False
    in_multi = False
    in_single = False

    new_str = []
    index = 0

    for match in re.finditer(tokenizer, string):
        if not (in_multi or in_single):
            tmp = string[index:match.start()]
            new_str.append(tmp)
        else:
            # Replace comments with white space so that the JSON parser reports
            # the correct column numbers on parsing errors.
            new_str.append(' ' * (match.start() - index))

        index = match.end()
        val = match.group()

        if val == '"' and not (in_multi or in_single):
            escaped = end_slashes_re.search(string, 0, match.start())

            # start of string or unescaped quote character to end string
            if not in_string or (escaped is None or len(escaped.group()) % 2 == 0):  # noqa
                in_string = not in_string
            index -= 1  # include " character in next catch
        elif not (in_string or in_multi or in_single):
            if val == '/*':
                in_multi = True
            elif val == '//':
                in_single = True
        elif val == '*/' and in_multi and not (in_string or in_single):
            in_multi = False
            new_str.append(' ' * len(val))
        elif val in '\r\n' and not (in_multi or in_string) and in_single:
            in_single = False
        elif not in_multi or in_single:  # noqa
            new_str.append(val)

        if val in '\r\n':
            new_str.append(val)
        elif in_multi or in_single:
            new_str.append(' ' * len(val))

    new_str.append(string[index:])
    return ''.join(new_str)


def remove_control_characters(s):
    """
    https://github.com/html5lib/html5lib-python/issues/96#issuecomment-43438438
    """
    def str_to_int(s, default, base=10):
        if int(s, base) < 0x10000:
            return chr(int(s, base))
        return default
    s = re.sub(r"&#(\d+);?", lambda c: str_to_int(c.group(1), c.group(0)), s)
    s = re.sub(r"&#[xX]([0-9a-fA-F]+);?", lambda c: str_to_int(c.group(1), c.group(0), base=16), s)
    s = re.sub(r"[\x00-\x08\x0b\x0e-\x1f\x7f]", "", s)
    return s


def get_db_engine(args, database_name):
    if args.replicated_database:
        return f" ON CLUSTER test_cluster_database_replicated \
            ENGINE=Replicated('/test/clickhouse/db/{database_name}', \
            '{{shard}}', '{{replica}}')"
    if args.db_engine:
        return " ENGINE=" + args.db_engine
    return ""   # Will use default engine


def configure_testcase_args(args, case_file, suite_tmp_dir, stderr_file):
    testcase_args = copy.deepcopy(args)

    testcase_args.testcase_start_time = datetime.now()
    testcase_basename = os.path.basename(case_file)
    testcase_args.testcase_client = f"{testcase_args.client} --log_comment='{testcase_basename}'"

    if testcase_args.database:
        database = testcase_args.database
        os.environ.setdefault("CLICKHOUSE_DATABASE", database)
        os.environ.setdefault("CLICKHOUSE_TMP", suite_tmp_dir)
    else:
        # If --database is not specified, we will create temporary database with unique name
        # And we will recreate and drop it for each test
        def random_str(length=6):
            alphabet = string.ascii_lowercase + string.digits
            return ''.join(random.choice(alphabet) for _ in range(length))
        database = 'test_{suffix}'.format(suffix=random_str())

        with open(stderr_file, 'w') as stderr:
            client_cmd = testcase_args.testcase_client + " " \
                + get_additional_client_options(args)

            clickhouse_proc_create = open_client_process(
                universal_newlines=True,
                client_args=client_cmd,
                stderr_file=stderr)

            try:
                clickhouse_proc_create.communicate(("CREATE DATABASE " + database + get_db_engine(testcase_args, database)), timeout=testcase_args.timeout)
            except TimeoutExpired:
                total_time = (datetime.now() - testcase_args.testcase_start_time).total_seconds()
                return clickhouse_proc_create, "", "Timeout creating database {} before test".format(database), total_time

        os.environ["CLICKHOUSE_DATABASE"] = database
        # Set temporary directory to match the randomly generated database,
        # because .sh tests also use it for temporary files and we want to avoid
        # collisions.
        testcase_args.test_tmp_dir = os.path.join(suite_tmp_dir, database)
        os.mkdir(testcase_args.test_tmp_dir)
        os.environ.setdefault("CLICKHOUSE_TMP", testcase_args.test_tmp_dir)

    testcase_args.testcase_database = database

    return testcase_args

def run_single_test(args, ext, server_logs_level, client_options, case_file, stdout_file, stderr_file):
    client = args.testcase_client
    start_time = args.testcase_start_time
    database = args.testcase_database

    # This is for .sh tests
    os.environ["CLICKHOUSE_LOG_COMMENT"] = case_file

    params = {
        'client': client + ' --database=' + database,
        'logs_level': server_logs_level,
        'options': client_options,
        'test': case_file,
        'stdout': stdout_file,
        'stderr': stderr_file,
    }

    # >> append to stderr (but not stdout since it is not used there),
    # because there are also output of per test database creation
    if not args.database:
        pattern = '{test} > {stdout} 2>> {stderr}'
    else:
        pattern = '{test} > {stdout} 2> {stderr}'

    if ext == '.sql':
        pattern = "{client} --send_logs_level={logs_level} --testmode --multiquery {options} < " + pattern

    command = pattern.format(**params)

    proc = Popen(command, shell=True, env=os.environ)

    while (datetime.now() - start_time).total_seconds() < args.timeout and proc.poll() is None:
        sleep(0.01)

    need_drop_database = not args.database
    if need_drop_database and args.no_drop_if_fail:
        maybe_passed = (proc.returncode == 0) and (proc.stderr is None) and (proc.stdout is None or 'Exception' not in proc.stdout)
        need_drop_database = not maybe_passed

    if need_drop_database:
        with open(stderr_file, 'a') as stderr:
            clickhouse_proc_create = open_client_process(client, universal_newlines=True, stderr_file=stderr)

        seconds_left = max(args.timeout - (datetime.now() - start_time).total_seconds(), 20)

        try:
            drop_database_query = "DROP DATABASE " + database
            if args.replicated_database:
                drop_database_query += " ON CLUSTER test_cluster_database_replicated"
            clickhouse_proc_create.communicate((drop_database_query), timeout=seconds_left)
        except TimeoutExpired:
            # kill test process because it can also hung
            if proc.returncode is None:
                try:
                    proc.kill()
                except OSError as e:
                    if e.errno != ESRCH:
                        raise

            total_time = (datetime.now() - start_time).total_seconds()
            return clickhouse_proc_create, "", f"Timeout dropping database {database} after test", total_time

        shutil.rmtree(args.test_tmp_dir)

    total_time = (datetime.now() - start_time).total_seconds()

    # Normalize randomized database names in stdout, stderr files.
    os.system("LC_ALL=C sed -i -e 's/{test_db}/default/g' {file}".format(test_db=database, file=stdout_file))
    if args.hide_db_name:
        os.system("LC_ALL=C sed -i -e 's/{test_db}/default/g' {file}".format(test_db=database, file=stderr_file))
    if args.replicated_database:
        os.system("LC_ALL=C sed -i -e 's|/auto_{{shard}}||g' {file}".format(file=stdout_file))
        os.system("LC_ALL=C sed -i -e 's|auto_{{replica}}||g' {file}".format(file=stdout_file))

    # Normalize hostname in stdout file.
    os.system("LC_ALL=C sed -i -e 's/{hostname}/localhost/g' {file}".format(hostname=socket.gethostname(), file=stdout_file))

    stdout = open(stdout_file, 'rb').read() if os.path.exists(stdout_file) else b''
    stdout = str(stdout, errors='replace', encoding='utf-8')
    stderr = open(stderr_file, 'rb').read() if os.path.exists(stderr_file) else b''
    stderr = str(stderr, errors='replace', encoding='utf-8')

    return proc, stdout, stderr, total_time


def need_retry(stdout, stderr):
    return any(msg in stdout for msg in MESSAGES_TO_RETRY) or any(msg in stderr for msg in MESSAGES_TO_RETRY)


def get_processlist(args):
    try:
        query = b"SHOW PROCESSLIST FORMAT Vertical"

        if args.replicated_database:
            query = b"SELECT materialize((hostName(), tcpPort())) as host, * " \
                    b"FROM clusterAllReplicas('test_cluster_database_replicated', system.processes) " \
                    b"WHERE query NOT LIKE '%system.processes%' FORMAT Vertical"

        clickhouse_proc = open_client_process(args.client)

        (stdout, _) = clickhouse_proc.communicate((query), timeout=20)

        return False, stdout.decode('utf-8')
    except Exception as ex:
        print("Exception", ex)
        return True, ""


# collect server stacktraces using gdb
def get_stacktraces_from_gdb(server_pid):
    try:
        cmd = f"gdb -batch -ex 'thread apply all backtrace' -p {server_pid}"
        return subprocess.check_output(cmd, shell=True).decode('utf-8')
    except Exception as e:
        print(f"Error occurred while receiving stack traces from gdb: {e}")
        return None


# collect server stacktraces from system.stack_trace table
# it does not work in Sandbox
def get_stacktraces_from_clickhouse(client, replicated_database=False):
    replicated_msg = \
        "{} --allow_introspection_functions=1 --skip_unavailable_shards=1 --query \
        \"SELECT materialize((hostName(), tcpPort())) as host, thread_id, \
        arrayStringConcat(arrayMap(x, y -> concat(x, ': ', y), \
        arrayMap(x -> addressToLine(x), trace), \
        arrayMap(x -> demangle(addressToSymbol(x)), trace)), '\n') as trace \
        FROM clusterAllReplicas('test_cluster_database_replicated', 'system.stack_trace') \
        ORDER BY host, thread_id FORMAT Vertical\"".format(client)

    msg = \
        "{} --allow_introspection_functions=1 --query \
        \"SELECT arrayStringConcat(arrayMap(x, y -> concat(x, ': ', y), \
        arrayMap(x -> addressToLine(x), trace), \
        arrayMap(x -> demangle(addressToSymbol(x)), trace)), '\n') as trace \
        FROM system.stack_trace FORMAT Vertical\"".format(client)

    try:
        return subprocess.check_output(
            replicated_msg if replicated_database else msg,
            shell=True, stderr=subprocess.STDOUT).decode('utf-8')
    except Exception as e:
        print(f"Error occurred while receiving stack traces from client: {e}")
        return None


def print_stacktraces() -> None:
    server_pid = get_server_pid()

    bt = None

    if server_pid and not args.replicated_database:
        print("")
        print(f"Located ClickHouse server process {server_pid} listening at TCP port {args.tcp_port}")
        print("Collecting stacktraces from all running threads with gdb:")

        bt = get_stacktraces_from_gdb(server_pid)

        if len(bt) < 1000:
            print("Got suspiciously small stacktraces: ", bt)
            bt = None

    if bt is None:
        print("\nCollecting stacktraces from system.stacktraces table:")

        bt = get_stacktraces_from_clickhouse(
            args.client, args.replicated_database)

    if bt is not None:
        print(bt)
        return

    print(colored(
        f"\nUnable to locate ClickHouse server process listening at TCP port {args.tcp_port}. "
         "It must have crashed or exited prematurely!",
        args, "red", attrs=["bold"]))


def get_server_pid():
    # lsof does not work in stress tests for some reason
    cmd_lsof = f"lsof -i tcp:{args.tcp_port} -s tcp:LISTEN -Fp | awk '/^p[0-9]+$/{{print substr($0, 2)}}'"
    cmd_pidof = "pidof -s clickhouse-server"

    commands = [cmd_lsof, cmd_pidof]
    output = None

    for cmd in commands:
        try:
            output = subprocess.check_output(cmd, shell=True, stderr=subprocess.STDOUT, universal_newlines=True)
            if output:
                return int(output)
        except Exception as e:
            print(f"Cannot get server pid with {cmd}, got {output}: {e}")

    return None  # most likely server is dead


def colored(text, args, color=None, on_color=None, attrs=None):
    if termcolor and (sys.stdout.isatty() or args.force_color):
        return termcolor.colored(text, color, on_color, attrs)
    else:
        return text


stop_time = None
exit_code = multiprocessing.Value("i", 0)
server_died = multiprocessing.Event()
stop_tests_triggered_lock = multiprocessing.Lock()
stop_tests_triggered = multiprocessing.Event()
queue = multiprocessing.Queue(maxsize=1)


def print_test_time(test_time) -> str:
    if args.print_time:
        return " {0:.2f} sec.".format(test_time)
    else:
        return ''


def should_skip_test_by_name(name: str, test_ext: str) -> Tuple[bool, str]:
    if args.skip and any(s in name for s in args.skip):
        return True, "skip"

    if not args.zookeeper and ('zookeeper' in name or 'replica' in name):
        return True, "no zookeeper"

    if not args.shard and \
        ('shard' in name or 'distributed' in name or 'global' in name):
        return True, "no shard"

    # Tests for races and deadlocks usually are run in a loop for a significant
    # amount of time
    if args.no_long and \
        ('long' in name or 'deadlock' in name or 'race' in name):
        return True, "no long"

    if not USE_JINJA and test_ext.endswith("j2"):
        return True, "no jinja"

    return False, ""


def should_skip_disabled_test(name: str, suite_dir: str) -> Tuple[bool, str]:
    disabled_file = os.path.join(suite_dir, name) + '.disabled'

    if os.path.exists(disabled_file) and not args.disabled:
        return True, open(disabled_file, 'r').read()

    return False, ""


# should skip test, should increment skipped_total, skip reason
def should_skip_test(name: str, test_ext: str, suite_dir: str) -> Tuple[bool, bool, str]:
    should_skip, skip_reason = should_skip_test_by_name(name, test_ext)

    if should_skip:
        return True, True, skip_reason

    should_skip, skip_reason = should_skip_disabled_test(name, suite_dir)

    return should_skip, False, skip_reason


def send_test_name_failed(suite: str, case: str) -> bool:
    clickhouse_proc = open_client_process(args.client, universal_newlines=True)

    failed_to_check = False

    pid = os.getpid()
    query = f"SELECT 'Running test {suite}/{case} from pid={pid}';"

    try:
        clickhouse_proc.communicate((query), timeout=20)
    except:
        failed_to_check = True

    return failed_to_check or clickhouse_proc.returncode != 0


restarted_tests = []  # (test, stderr)

# def run_tests_array(all_tests, suite, suite_dir, suite_tmp_dir, run_total):
def run_tests_array(all_tests_with_params):
    all_tests, num_tests, suite, suite_dir, suite_tmp_dir = all_tests_with_params
    global stop_time
    global exit_code
    global server_died

    OP_SQUARE_BRACKET = colored("[", args, attrs=['bold'])
    CL_SQUARE_BRACKET = colored("]", args, attrs=['bold'])

    MSG_FAIL = OP_SQUARE_BRACKET + colored(" FAIL ", args, "red", attrs=['bold']) + CL_SQUARE_BRACKET
    MSG_UNKNOWN = OP_SQUARE_BRACKET + colored(" UNKNOWN ", args, "yellow", attrs=['bold']) + CL_SQUARE_BRACKET
    MSG_OK = OP_SQUARE_BRACKET + colored(" OK ", args, "green", attrs=['bold']) + CL_SQUARE_BRACKET
    MSG_SKIPPED = OP_SQUARE_BRACKET + colored(" SKIPPED ", args, "cyan", attrs=['bold']) + CL_SQUARE_BRACKET

    passed_total = 0
    skipped_total = 0
    failures_total = 0
    failures = 0
    failures_chain = 0
    start_time = datetime.now()

    is_concurrent = multiprocessing.current_process().name != "MainProcess"

    client_options = get_additional_client_options(args)

    if num_tests > 0:
        about = 'about ' if is_concurrent else ''
        proc_name = multiprocessing.current_process().name
        print(f"\nRunning {about}{num_tests} {suite} tests ({proc_name}).\n")

    while True:
        if is_concurrent:
            case = queue.get()
            if not case:
                break
        else:
            if all_tests:
                case = all_tests.pop(0)
            else:
                break

        if server_died.is_set():
            stop_tests()
            break

        if stop_time and time() > stop_time:
            print("\nStop tests run because global time limit is exceeded.\n")
            stop_tests()
            break

        case_file = os.path.join(suite_dir, case)
        (name, ext) = os.path.splitext(case)

        try:
            status = ''
            if not is_concurrent:
                sys.stdout.flush()
                sys.stdout.write("{0:72}".format(removesuffix(name, ".gen", ".sql") + ": "))
                # This flush is needed so you can see the test name of the long
                # running test before it will finish. But don't do it in parallel
                # mode, so that the lines don't mix.
                sys.stdout.flush()
            else:
                status = "{0:72}".format(removesuffix(name, ".gen", ".sql") + ": ")

            skip_test, increment_skip_count, skip_reason = \
                should_skip_test(name, ext, suite_dir)

            if skip_test:
                status += MSG_SKIPPED + f" - {skip_reason}\n"

                if increment_skip_count:
                    skipped_total += 1
            else:
                if args.testname and send_test_name_failed(suite, case):
                    failures += 1
                    print("Server does not respond to health check")
                    server_died.set()
                    stop_tests()
                    break

                file_suffix = ('.' + str(os.getpid())) if is_concurrent and args.test_runs > 1 else ''
                reference_file = get_reference_file(suite_dir, name)
                stdout_file = os.path.join(suite_tmp_dir, name) + file_suffix + '.stdout'
                stderr_file = os.path.join(suite_tmp_dir, name) + file_suffix + '.stderr'

                testcase_args = configure_testcase_args(args, case_file, suite_tmp_dir, stderr_file)
                proc, stdout, stderr, total_time = run_single_test(testcase_args, ext, server_logs_level, client_options, case_file, stdout_file, stderr_file)

                if proc.returncode is None:
                    try:
                        proc.kill()
                    except OSError as e:
                        if e.errno != ESRCH:
                            raise

                    failures += 1
                    status += MSG_FAIL
                    status += print_test_time(total_time)
                    status += " - Timeout!\n"
                    if stderr:
                        status += stderr
                    status += 'Database: ' + testcase_args.testcase_database
                else:
                    counter = 1
                    while need_retry(stdout, stderr):
                        restarted_tests.append((case_file, stderr))
                        testcase_args = configure_testcase_args(args, case_file, suite_tmp_dir, stderr_file)
                        proc, stdout, stderr, total_time = run_single_test(testcase_args, ext, server_logs_level, client_options, case_file, stdout_file, stderr_file)
                        sleep(2**counter)
                        counter += 1
                        if MAX_RETRIES < counter:
                            if args.replicated_database:
                                if DISTRIBUTED_DDL_TIMEOUT_MSG in stderr:
                                    server_died.set()
                            break

                    if proc.returncode != 0:
                        failures += 1
                        failures_chain += 1
                        status += MSG_FAIL
                        status += print_test_time(total_time)
                        status += ' - return code {}\n'.format(proc.returncode)

                        if stderr:
                            status += stderr

                        # Stop on fatal errors like segmentation fault. They are sent to client via logs.
                        if ' <Fatal> ' in stderr:
                            server_died.set()

                        if testcase_args.stop \
                            and ('Connection refused' in stderr or 'Attempt to read after eof' in stderr) \
                            and 'Received exception from server' not in stderr:
                            server_died.set()

                        if os.path.isfile(stdout_file):
                            status += ", result:\n\n"
                            status += '\n'.join(
                                open(stdout_file).read().split('\n')[:100])
                            status += '\n'

                        status += 'Database: ' + testcase_args.testcase_database

                    elif stderr:
                        failures += 1
                        failures_chain += 1
                        status += MSG_FAIL
                        status += print_test_time(total_time)
                        status += " - having stderror:\n{}\n".format(
                            '\n'.join(stderr.split('\n')[:100]))
                        status += 'Database: ' + testcase_args.testcase_database
                    elif 'Exception' in stdout:
                        failures += 1
                        failures_chain += 1
                        status += MSG_FAIL
                        status += print_test_time(total_time)
                        status += " - having exception in stdout:\n{}\n".format(
                            '\n'.join(stdout.split('\n')[:100]))
                        status += 'Database: ' + testcase_args.testcase_database
                    elif '@@SKIP@@' in stdout:
                        skipped_total += 1
                        skip_reason = stdout.replace('@@SKIP@@', '').rstrip("\n")
                        status += MSG_SKIPPED + f" - {skip_reason}\n"
                    elif reference_file is None:
                        status += MSG_UNKNOWN
                        status += print_test_time(total_time)
                        status += " - no reference file\n"
                        status += 'Database: ' + testcase_args.testcase_database
                    else:
                        result_is_different = subprocess.call(['diff', '-q', reference_file, stdout_file], stdout=PIPE)

                        if result_is_different:
                            diff = Popen(['diff', '-U', str(testcase_args.unified), reference_file, stdout_file], stdout=PIPE, universal_newlines=True).communicate()[0]
                            failures += 1
                            status += MSG_FAIL
                            status += print_test_time(total_time)
                            status += " - result differs with reference:\n{}\n".format(diff)
                            status += 'Database: ' + testcase_args.testcase_database
                        else:
                            if testcase_args.test_runs > 1 and total_time > 60 and 'long' not in name:
                                # We're in Flaky Check mode, check the run time as well while we're at it.
                                failures += 1
                                failures_chain += 1
                                status += MSG_FAIL
                                status += print_test_time(total_time)
                                status += " - Test runs too long (> 60s). Make it faster.\n"
                                status += 'Database: ' + testcase_args.testcase_database
                            else:
                                passed_total += 1
                                failures_chain = 0
                                status += MSG_OK
                                status += print_test_time(total_time)
                                status += "\n"
                                if os.path.exists(stdout_file):
                                    os.remove(stdout_file)
                                if os.path.exists(stderr_file):
                                    os.remove(stderr_file)

            if status and not status.endswith('\n'):
                status += '\n'

            sys.stdout.write(status)
            sys.stdout.flush()
        except KeyboardInterrupt as e:
            print(colored("Break tests execution", args, "red"))
            stop_tests()
            raise e
        except:
            exc_type, exc_value, tb = sys.exc_info()
            failures += 1

            exc_name = exc_type.__name__
            traceback_str = "\n".join(traceback.format_tb(tb, 10))

            print(f"{MSG_FAIL} - Test internal error: {exc_name}")
            print(f"{exc_value}\n{traceback_str}")

        if failures_chain >= 20:
            stop_tests()
            break

    failures_total = failures_total + failures

    if failures_total > 0:
        print(colored(f"\nHaving {failures_total} errors! {passed_total} tests passed."
            f" {skipped_total} tests skipped. {(datetime.now() - start_time).total_seconds():.2f} s elapsed"
            f' ({multiprocessing.current_process().name}).',
            args, "red", attrs=["bold"]))
        exit_code.value = 1
    else:
        print(colored(f"\n{passed_total} tests passed. {skipped_total} tests skipped."
            f" {(datetime.now() - start_time).total_seconds():.2f} s elapsed"
            f' ({multiprocessing.current_process().name}).',
            args, "green", attrs=["bold"]))

    sys.stdout.flush()


server_logs_level = "warning"


def check_server_started(client, retry_count):
    print("Connecting to ClickHouse server...", end='')

    sys.stdout.flush()

    while retry_count > 0:
        clickhouse_proc = open_client_process(client)
        (stdout, stderr) = clickhouse_proc.communicate(b"SELECT 1")

        if clickhouse_proc.returncode == 0 and stdout.startswith(b"1"):
            print(" OK")
            sys.stdout.flush()
            return True

        if clickhouse_proc.returncode == 210:
            # Connection refused, retry
            print('.', end='')
            sys.stdout.flush()
            retry_count -= 1
            sleep(0.5)
            continue

        # FIXME Some old comment, maybe now CH supports Python3 ?
        # We can't print this, because for some reason this is python 2,
        # and args appeared in 3.3. To hell with it.
        # print(''.join(clickhouse_proc.args))

        # Other kind of error, fail.

        code: int = clickhouse_proc.returncode

        print(f"\nClient invocation failed with code {code}:\n\
            stdout: {stdout}\n\
            stderr: {stderr}")

        sys.stdout.flush()

        return False

    print('\nAll connection tries failed')
    sys.stdout.flush()

    return False


class BuildFlags():
    THREAD = 'thread-sanitizer'
    ADDRESS = 'address-sanitizer'
    UNDEFINED = 'ub-sanitizer'
    MEMORY = 'memory-sanitizer'
    DEBUG = 'debug-build'
    UNBUNDLED = 'unbundled-build'
    RELEASE = 'release-build'
    DATABASE_ORDINARY = 'database-ordinary'
    POLYMORPHIC_PARTS = 'polymorphic-parts'
    DATABASE_REPLICATED = 'database-replicated'


def collect_build_flags(client):
    clickhouse_proc = open_client_process(client)
    (stdout, stderr) = clickhouse_proc.communicate(b"SELECT value FROM system.build_options WHERE name = 'CXX_FLAGS'")
    result = []

    if clickhouse_proc.returncode == 0:
        if b'-fsanitize=thread' in stdout:
            result.append(BuildFlags.THREAD)
        elif b'-fsanitize=address' in stdout:
            result.append(BuildFlags.ADDRESS)
        elif b'-fsanitize=undefined' in stdout:
            result.append(BuildFlags.UNDEFINED)
        elif b'-fsanitize=memory' in stdout:
            result.append(BuildFlags.MEMORY)
    else:
        raise Exception("Cannot get information about build from server errorcode {}, stderr {}".format(clickhouse_proc.returncode, stderr))

    clickhouse_proc = open_client_process(client)
    (stdout, stderr) = clickhouse_proc.communicate(b"SELECT value FROM system.build_options WHERE name = 'BUILD_TYPE'")

    if clickhouse_proc.returncode == 0:
        if b'Debug' in stdout:
            result.append(BuildFlags.DEBUG)
        elif b'RelWithDebInfo' in stdout or b'Release' in stdout:
            result.append(BuildFlags.RELEASE)
    else:
        raise Exception("Cannot get information about build from server errorcode {}, stderr {}".format(clickhouse_proc.returncode, stderr))

    clickhouse_proc = open_client_process(client)
    (stdout, stderr) = clickhouse_proc.communicate(b"SELECT value FROM system.build_options WHERE name = 'UNBUNDLED'")

    if clickhouse_proc.returncode == 0:
        if b'ON' in stdout or b'1' in stdout:
            result.append(BuildFlags.UNBUNDLED)
    else:
        raise Exception("Cannot get information about build from server errorcode {}, stderr {}".format(clickhouse_proc.returncode, stderr))

    clickhouse_proc = open_client_process(client)
    (stdout, stderr) = clickhouse_proc.communicate(b"SELECT value FROM system.settings WHERE name = 'default_database_engine'")

    if clickhouse_proc.returncode == 0:
        if b'Ordinary' in stdout:
            result.append(BuildFlags.DATABASE_ORDINARY)
    else:
        raise Exception("Cannot get information about build from server errorcode {}, stderr {}".format(clickhouse_proc.returncode, stderr))

    clickhouse_proc = open_client_process(client)
    (stdout, stderr) = clickhouse_proc.communicate(b"SELECT value FROM system.merge_tree_settings WHERE name = 'min_bytes_for_wide_part'")

    if clickhouse_proc.returncode == 0:
        if stdout == b'0\n':
            result.append(BuildFlags.POLYMORPHIC_PARTS)
    else:
        raise Exception("Cannot get inforamtion about build from server errorcode {}, stderr {}".format(clickhouse_proc.returncode, stderr))

    return result


def suite_key_func(item: str) -> Union[int, Tuple[int, str]]:
    if args.order == 'random':
        return random.random()

    if -1 == item.find('_'):
        return 99998, ''

    prefix, suffix = item.split('_', 1)

    try:
        return int(prefix), suffix
    except ValueError:
        return 99997, ''


def tests_in_suite_key_func(item: str) -> int:
    if args.order == 'random':
        return random.random()

    reverse = 1 if args.order == 'asc' else -1

    if -1 == item.find('_'):
        return 99998

    prefix, _ = item.split('_', 1)

    try:
        return reverse * int(prefix)
    except ValueError:
        return 99997


def extract_key(key: str) -> str:
    return subprocess.getstatusoutput(
        args.extract_from_config +
        " --try --config " +
        args.configserver + key)[1]


def open_client_process(
    client_args: str,
    universal_newlines: bool = False,
    stderr_file: Optional[TextIO] = None):
    return Popen(
        shlex.split(client_args), stdin=PIPE, stdout=PIPE,
        stderr=stderr_file if stderr_file is not None else PIPE,
        universal_newlines=True if universal_newlines else None)



def do_run_tests(jobs, suite, suite_dir, suite_tmp_dir, all_tests, parallel_tests, sequential_tests, parallel):
    if jobs > 1 and len(parallel_tests) > 0:
        print("Found", len(parallel_tests), "parallel tests and", len(sequential_tests), "sequential tests")
        run_n, run_total = parallel.split('/')
        run_n = float(run_n)
        run_total = float(run_total)
        tests_n = len(parallel_tests)
        if run_total > tests_n:
            run_total = tests_n

        if jobs > tests_n:
            jobs = tests_n
        if jobs > run_total:
            run_total = jobs

        batch_size = max(1, len(parallel_tests) // jobs)
        parallel_tests_array = []
        for _ in range(jobs):
            parallel_tests_array.append((None, batch_size, suite, suite_dir, suite_tmp_dir))

        with closing(multiprocessing.Pool(processes=jobs)) as pool:
            pool.map_async(run_tests_array, parallel_tests_array)

            for suit in parallel_tests:
                queue.put(suit)

            for _ in range(jobs):
                queue.put(None)

            queue.close()

        pool.join()

        run_tests_array((sequential_tests, len(sequential_tests), suite, suite_dir, suite_tmp_dir))
        return len(sequential_tests) + len(parallel_tests)
    else:
        num_tests = len(all_tests)
        run_tests_array((all_tests, num_tests, suite, suite_dir, suite_tmp_dir))
        return num_tests


def is_test_from_dir(suite_dir, case):
    case_file = os.path.join(suite_dir, case)
    # We could also test for executable files (os.access(case_file, os.X_OK),
    # but it interferes with 01610_client_spawn_editor.editor, which is invoked
    # as a query editor in the test, and must be marked as executable.
    return os.path.isfile(case_file) and any(case_file.endswith(suppotred_ext) for suppotred_ext in TEST_FILE_EXTENSIONS)


def removesuffix(text, *suffixes):
    """
    Added in python 3.9
    https://www.python.org/dev/peps/pep-0616/

    This version can work with several possible suffixes
    """
    for suffix in suffixes:
        if suffix and text.endswith(suffix):
            return text[:-len(suffix)]
    return text


def render_test_template(j2env, suite_dir, test_name):
    """
    Render template for test and reference file if needed
    """

    if j2env is None:
        return test_name

    test_base_name = removesuffix(test_name, ".sql.j2", ".sql")

    reference_file_name = test_base_name + ".reference.j2"
    reference_file_path = os.path.join(suite_dir, reference_file_name)
    if os.path.isfile(reference_file_path):
        tpl = j2env.get_template(reference_file_name)
        tpl.stream().dump(os.path.join(suite_dir, test_base_name) + ".gen.reference")

    if test_name.endswith(".sql.j2"):
        tpl = j2env.get_template(test_name)
        generated_test_name = test_base_name + ".gen.sql"
        tpl.stream().dump(os.path.join(suite_dir, generated_test_name))
        return generated_test_name

    return test_name


def get_selected_tests(suite_dir, patterns):
    """
    Find all files with tests, filter, render templates
    """

    j2env = jinja2.Environment(
        loader=jinja2.FileSystemLoader(suite_dir),
        keep_trailing_newline=True,
    ) if USE_JINJA else None

    for test_name in os.listdir(suite_dir):
        if not is_test_from_dir(suite_dir, test_name):
            continue
        if patterns and not any(re.search(pattern, test_name) for pattern in patterns):
            continue
        if USE_JINJA and test_name.endswith(".gen.sql"):
            continue
        test_name = render_test_template(j2env, suite_dir, test_name)
        yield test_name


def get_tests_list(suite_dir, patterns, test_runs, sort_key):
    """
    Return list of tests file names to run
    """

    all_tests = list(get_selected_tests(suite_dir, patterns))
    all_tests = all_tests * test_runs
    all_tests.sort(key=sort_key)
    return all_tests


def get_reference_file(suite_dir, name):
    """
    Returns reference file name for specified test
    """

    name = removesuffix(name, ".gen")
    for ext in ['.reference', '.gen.reference']:
        reference_file = os.path.join(suite_dir, name) + ext
        if os.path.isfile(reference_file):
            return reference_file
    return None


def main(args):
    global server_died
    global stop_time
    global exit_code
    global server_logs_level

    def is_data_present():
        clickhouse_proc = open_client_process(args.client)
        (stdout, stderr) = clickhouse_proc.communicate(b"EXISTS TABLE test.hits")
        if clickhouse_proc.returncode != 0:
            raise CalledProcessError(clickhouse_proc.returncode, args.client, stderr)

        return stdout.startswith(b'1')

    if not check_server_started(args.client, args.server_check_retries):
        raise Exception(
            "Server is not responding. Cannot execute 'SELECT 1' query. \
            If you are using split build, you have to specify -c option.")

    build_flags = collect_build_flags(args.client)

    if args.replicated_database:
        build_flags.append(BuildFlags.DATABASE_REPLICATED)

    if args.use_skip_list:
        tests_to_skip_from_list = collect_tests_to_skip(args.skip_list_path, build_flags)
    else:
        tests_to_skip_from_list = set()

    if args.skip:
        args.skip = set(args.skip) | tests_to_skip_from_list
    else:
        args.skip = tests_to_skip_from_list

    if args.use_skip_list and not args.sequential:
        args.sequential = collect_sequential_list(args.skip_list_path)

    base_dir = os.path.abspath(args.queries)
    tmp_dir = os.path.abspath(args.tmp)

    # Keep same default values as in queries/shell_config.sh
    os.environ.setdefault("CLICKHOUSE_BINARY", args.binary)
    # os.environ.setdefault("CLICKHOUSE_CLIENT", args.client)
    os.environ.setdefault("CLICKHOUSE_CONFIG", args.configserver)

    if args.configclient:
        os.environ.setdefault("CLICKHOUSE_CONFIG_CLIENT", args.configclient)

    # Force to print server warnings in stderr
    # Shell scripts could change logging level
    os.environ.setdefault("CLICKHOUSE_CLIENT_SERVER_LOGS_LEVEL", server_logs_level)

    # This code is bad as the time is not monotonic
    if args.global_time_limit:
        stop_time = time() + args.global_time_limit

    if args.zookeeper is None:
        try:
            args.zookeeper = int(extract_key(" --key zookeeper | grep . | wc -l")) > 0
        except ValueError:
            args.zookeeper = False

    if args.shard is None:
        args.shard = bool(extract_key(' --key listen_host | grep -E "127.0.0.2|::"'))

    def create_common_database(args, db_name):
        create_database_retries = 0
        while create_database_retries < MAX_RETRIES:
            client_cmd = args.client + " " + get_additional_client_options(args)

            clickhouse_proc_create = open_client_process(client_cmd, universal_newlines=True)

            (stdout, stderr) = clickhouse_proc_create.communicate(("CREATE DATABASE IF NOT EXISTS " + db_name + get_db_engine(args, db_name)))

            if not need_retry(stdout, stderr):
                break
            create_database_retries += 1

    if args.database and args.database != "test":
        create_common_database(args, args.database)

    create_common_database(args, "test")

    total_tests_run = 0

    for suite in sorted(os.listdir(base_dir), key=suite_key_func):
        if server_died.is_set():
            break

        suite_dir = os.path.join(base_dir, suite)
        suite_re_obj = re.search('^[0-9]+_(.*)$', suite)
        if not suite_re_obj:  # skip .gitignore and so on
            continue

        suite_tmp_dir = os.path.join(tmp_dir, suite)
        if not os.path.exists(suite_tmp_dir):
            os.makedirs(suite_tmp_dir)

        suite = suite_re_obj.group(1)

        if os.path.isdir(suite_dir):
            if 'stateful' in suite and not args.no_stateful and not is_data_present():
                print("Won't run stateful tests because test data wasn't loaded.")
                continue
            if 'stateless' in suite and args.no_stateless:
                print("Won't run stateless tests because they were manually disabled.")
                continue
            if 'stateful' in suite and args.no_stateful:
                print("Won't run stateful tests because they were manually disabled.")
                continue

            all_tests = get_tests_list(
                suite_dir, args.test, args.test_runs, tests_in_suite_key_func)

            jobs = args.jobs

            parallel_tests = []
            sequential_tests = []

            for test in all_tests:
                if any(s in test for s in args.sequential):
                    sequential_tests.append(test)
                else:
                    parallel_tests.append(test)

            total_tests_run += do_run_tests(
                jobs, suite, suite_dir, suite_tmp_dir, all_tests, parallel_tests, sequential_tests, args.parallel)

    if args.hung_check:

        # Some queries may execute in background for some time after test was finished. This is normal.
        for _ in range(1, 60):
            timeout, processlist = get_processlist(args)
            if timeout or not processlist:
                break
            sleep(1)

        if timeout or processlist:
            if processlist:
                print(colored("\nFound hung queries in processlist:", args, "red", attrs=["bold"]))
                print(processlist)
            else:
                print(colored("Seems like server hung and cannot respond to queries", args, "red", attrs=["bold"]))


            print_stacktraces()
            exit_code.value = 1
        else:
            print(colored("\nNo queries hung.", args, "green", attrs=["bold"]))

    if len(restarted_tests) > 0:
        print("\nSome tests were restarted:\n")

        for (test_case, stderr) in restarted_tests:
            print(test_case + "\n" + stderr + "\n")

    if total_tests_run == 0:
        print("No tests were run.")
        sys.exit(1)
    else:
        print("All tests have finished.")

    sys.exit(exit_code.value)


def find_binary(name):
    if os.path.exists(name) and os.access(name, os.X_OK):
        return True
    paths = os.environ.get("PATH").split(':')
    for path in paths:
        if os.access(os.path.join(path, name), os.X_OK):
            return True

    # maybe it wasn't in PATH
    if os.access(os.path.join('/usr/local/bin', name), os.X_OK):
        return True
    if os.access(os.path.join('/usr/bin', name), os.X_OK):
        return True
    return False


def get_additional_client_options(args):
    if args.client_option:
        return ' '.join('--' + option for option in args.client_option)

    return ''


def get_additional_client_options_url(args):
    if args.client_option:
        return '&'.join(args.client_option)

    return ''


def collect_tests_to_skip(skip_list_path, build_flags):
    result = set([])

    if not os.path.exists(skip_list_path):
        return result

    with open(skip_list_path, 'r') as skip_list_file:
        content = skip_list_file.read()

        # allows to have comments in skip_list.json
        skip_dict = json.loads(json_minify(content))

        for build_flag in build_flags:
            result |= set(skip_dict[build_flag])

    count = len(result)

    if count > 0:
        print(f"Found file with skip-list {skip_list_path}, {count} test will be skipped")

    return result


def collect_sequential_list(skip_list_path):
    if not os.path.exists(skip_list_path):
        return set([])

    with open(skip_list_path, 'r') as skip_list_file:
        content = skip_list_file.read()
        # allows to have comments in skip_list.json
        skip_dict = json.loads(json_minify(content))
        if 'parallel' in skip_dict:
            return skip_dict['parallel']
        return set([])


if __name__ == '__main__':
    # Move to a new process group and kill it at exit so that we don't have any
    # infinite tests processes left
    # (new process group is required to avoid killing some parent processes)
    os.setpgid(0, 0)
    signal.signal(signal.SIGTERM, signal_handler)
    signal.signal(signal.SIGINT, signal_handler)
    signal.signal(signal.SIGHUP, signal_handler)

    parser = ArgumentParser(description='ClickHouse functional tests')
    parser.add_argument('-q', '--queries', help='Path to queries dir')
    parser.add_argument('--tmp', help='Path to tmp dir')

    parser.add_argument('-b', '--binary', default='clickhouse',
        help='Path to clickhouse (if monolithic build, clickhouse-server otherwise) binary or name of binary in PATH')

    parser.add_argument('-c', '--client',
        help='Path to clickhouse-client (if split build, useless otherwise) binary of name of binary in PATH')

    parser.add_argument('--extract_from_config', help='extract-from-config program')
    parser.add_argument('--configclient', help='Client config (if you use not default ports)')
    parser.add_argument('--configserver', default='/etc/clickhouse-server/config.xml', help='Preprocessed server config')
    parser.add_argument('-o', '--output', help='Output xUnit compliant test report directory')
    parser.add_argument('-t', '--timeout', type=int, default=600, help='Timeout for each test case in seconds')
    parser.add_argument('--global_time_limit', type=int, help='Stop if executing more than specified time (after current test finished)')
    parser.add_argument('test', nargs='*', help='Optional test case name regex')
    parser.add_argument('-d', '--disabled', action='store_true', default=False, help='Also run disabled tests')
    parser.add_argument('--stop', action='store_true', default=None, dest='stop', help='Stop on network errors')
    parser.add_argument('--order', default='desc', choices=['asc', 'desc', 'random'], help='Run order')
    parser.add_argument('--testname', action='store_true', default=None, dest='testname', help='Make query with test name before test run')
    parser.add_argument('--hung-check', action='store_true', default=False)
    parser.add_argument('--force-color', action='store_true', default=False)
    parser.add_argument('--database', help='Database for tests (random name test_XXXXXX by default)')
    parser.add_argument('--no-drop-if-fail', action='store_true', help='Do not drop database for test if test has failed')
    parser.add_argument('--hide-db-name', action='store_true', help='Replace random database name with "default" in stderr')
    parser.add_argument('--parallel', default='1/1', help='One parallel test run number/total')
    parser.add_argument('-j', '--jobs', default=1, nargs='?', type=int, help='Run all tests in parallel')
    parser.add_argument('--test-runs', default=1, nargs='?', type=int, help='Run each test many times (useful for e.g. flaky check)')
    parser.add_argument('-U', '--unified', default=3, type=int, help='output NUM lines of unified context')
    parser.add_argument('-r', '--server-check-retries', default=30, type=int, help='Num of tries to execute SELECT 1 before tests started')
    parser.add_argument('--skip-list-path', help="Path to skip-list file")
    parser.add_argument('--use-skip-list', action='store_true', default=False, help="Use skip list to skip tests if found")
    parser.add_argument('--db-engine', help='Database engine name')
    parser.add_argument('--replicated-database', action='store_true', default=False, help='Run tests with Replicated database engine')
    parser.add_argument('--no-stateless', action='store_true', help='Disable all stateless tests')
    parser.add_argument('--no-stateful', action='store_true', help='Disable all stateful tests')
    parser.add_argument('--skip', nargs='+', help="Skip these tests")
    parser.add_argument('--sequential', nargs='+', help="Run these tests sequentially even if --parallel specified")
    parser.add_argument('--no-long', action='store_true', dest='no_long', help='Do not run long tests')
    parser.add_argument('--client-option', nargs='+', help='Specify additional client argument')
    parser.add_argument('--print-time', action='store_true', dest='print_time', help='Print test time')

    group = parser.add_mutually_exclusive_group(required=False)
    group.add_argument('--zookeeper', action='store_true', default=None, dest='zookeeper', help='Run zookeeper related tests')
    group.add_argument('--no-zookeeper', action='store_false', default=None, dest='zookeeper', help='Do not run zookeeper related tests')

    group = parser.add_mutually_exclusive_group(required=False)
    group.add_argument('--shard', action='store_true', default=None, dest='shard', help='Run sharding related tests (required to clickhouse-server listen 127.0.0.2 127.0.0.3)')
    group.add_argument('--no-shard', action='store_false', default=None, dest='shard', help='Do not run shard related tests')

    args = parser.parse_args()

    if args.queries and not os.path.isdir(args.queries):
        print(f"Cannot access the specified directory with queries ({args.queries})", file=sys.stderr)
        sys.exit(1)

    # Autodetect the directory with queries if not specified
    if args.queries is None:
        args.queries = 'queries'

    if not os.path.isdir(args.queries):
        # If we're running from the repo
        args.queries = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'queries')

    if not os.path.isdir(args.queries):
        # Next we're going to try some system directories, don't write 'stdout' files into them.
        if args.tmp is None:
            args.tmp = '/tmp/clickhouse-test'

        args.queries = '/usr/local/share/clickhouse-test/queries'

    if not os.path.isdir(args.queries):
        args.queries = '/usr/share/clickhouse-test/queries'

    if not os.path.isdir(args.queries):
        print("Failed to detect path to the queries directory. Please specify it with '--queries' option.", file=sys.stderr)
        sys.exit(1)

    print("Using queries from '" + args.queries + "' directory")

    if args.skip_list_path is None:
        args.skip_list_path = os.path.join(args.queries, 'skip_list.json')

    if args.sequential is None:
        args.sequential = set([])

    if args.tmp is None:
        args.tmp = args.queries
    if args.client is None:
        if find_binary(args.binary + '-client'):
            args.client = args.binary + '-client'

            print("Using " + args.client + " as client program (expecting split build)")
        elif find_binary(args.binary):
            args.client = args.binary + ' client'

            print("Using " + args.client + " as client program (expecting monolithic build)")
        else:
            print("No 'clickhouse' or 'clickhouse-client' client binary found", file=sys.stderr)
            parser.print_help()
            sys.exit(1)

        if args.configclient:
            args.client += ' --config-file=' + args.configclient

        if os.getenv("CLICKHOUSE_HOST"):
            args.client += ' --host=' + os.getenv("CLICKHOUSE_HOST")

        args.tcp_port = int(os.getenv("CLICKHOUSE_PORT_TCP", "9000"))
        args.client += f" --port={args.tcp_port}"

        if os.getenv("CLICKHOUSE_DATABASE"):
            args.client += ' --database=' + os.getenv("CLICKHOUSE_DATABASE")

    if args.client_option:
        # Set options for client
        if 'CLICKHOUSE_CLIENT_OPT' in os.environ:
            os.environ['CLICKHOUSE_CLIENT_OPT'] += ' '
        else:
            os.environ['CLICKHOUSE_CLIENT_OPT'] = ''

        os.environ['CLICKHOUSE_CLIENT_OPT'] += get_additional_client_options(args)

        # Set options for curl
        if 'CLICKHOUSE_URL_PARAMS' in os.environ:
            os.environ['CLICKHOUSE_URL_PARAMS'] += '&'
        else:
            os.environ['CLICKHOUSE_URL_PARAMS'] = ''

        os.environ['CLICKHOUSE_URL_PARAMS'] += get_additional_client_options_url(args)

    if args.extract_from_config is None:
        if os.access(args.binary + '-extract-from-config', os.X_OK):
            args.extract_from_config = args.binary + '-extract-from-config'
        else:
            args.extract_from_config = args.binary + ' extract-from-config'

    if args.jobs is None:
        args.jobs = multiprocessing.cpu_count()

    main(args)