Python pymongo.errors.ServerSelectionTimeoutError() Examples

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def __init__(self, server_config, auto_connect=True):
        """Initialise the client

        :param server_config: The server configuration
        :param auto_connect: Whether to automatically connect
        """
        self.server_config = server_config

        if auto_connect:
            if ServerSelectionTimeoutError:
                try:
                    self.connect(server_config)
                except ServerSelectionTimeoutError as e:
                    logging.warn(e.message)
                    sys.exit()
            else:
                self.connect(server_config) 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def loadMongo(chapter_docs):
    try:
        client = MongoClient('mongodb://localhost:27017/',
                             serverSelectionTimeoutMS=100)
        db = client['icd10']
        col = db['icd2016Codes']
        for chapter in chapter_docs:
            col.insert_one(chapter)
        return col.count()
    except ConnectionFailure as connectError:
        print("Connection Failure to MongoDB: {0}".format(connectError))
        sys.exit(1)
    except ServerSelectionTimeoutError as timeoutErr:
        print("Unable to connect Timeout: {0}".format(timeoutErr))
        sys.exit(1)
    except Exception as err:
        print ("Error: {0}".format(err.args)) 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def setUpClass(cls):
        """
        Instantiate the adapter before any tests in the test case run.
        """
        from pymongo.errors import ServerSelectionTimeoutError
        from pymongo import MongoClient

        cls.has_mongo_connection = False

        try:
            client = MongoClient(
                serverSelectionTimeoutMS=0.1
            )
            client.server_info()

            cls.adapter = MongoDatabaseAdapter(
                database_uri='mongodb://localhost:27017/chatterbot_test_database'
            )

            cls.has_mongo_connection = False

        except ServerSelectionTimeoutError:
            pass 

def __init__(self, ip, port, db_name):
        """Constructor"""

        self._client = MongoClient(ip, port)  # get client
        self._name = db_name
        self._db = self._client[db_name]

        # check if database is connected
        try:
            self._client.server_info()
            print("Connected to {}:{} - {}".format(ip, port, db_name))
        except errors.ServerSelectionTimeoutError:
            print("Failed to connect to database")
            exit()

        self._flights = self._db.flights
        self._airports = self._db.airports
        self._adj = self._db.adj 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def db_connect():
    maxSevSelDelay = 1
    try:
        mongo_host = 'localhost'
        mongo_port = 27017

        if 'MONGO_PORT_27017_TCP_ADDR' in os.environ :
            mongo_host = os.environ['MONGO_PORT_27017_TCP_ADDR']

        if 'MONGO_PORT_27017_TCP_PORT' in os.environ:
            mongo_port = int(os.environ['MONGO_PORT_27017_TCP_PORT'])

        client = MongoClient(mongo_host, mongo_port, serverSelectionTimeoutMS=maxSevSelDelay)
        client.server_info()
        return client

    except ServerSelectionTimeoutError as err:
        exit("Failed to connect to MongoDB.") 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def __init__(self, db_url: str, db_name: str, show_logs: bool = True):
        """
        :param db_url: str - url to MongoDB database, it can contain port eg: 'localhost:27017'
        :param db_name: str - database name
        :param show_logs: bool - used to suppress log messages
        """
        # setup MongoDB database connection
        self.db_url = db_url
        self.db_client = MongoClient(db_url, serverSelectionTimeoutMS=5000)
        self.db_database = self.db_client[db_name]
        self.db_collection = self.db_database.samples
        self.db_tags = self.db_database.tags
        self.db_file_storage = gridfs.GridFS(self.db_database)
        try:
            if show_logs:
                print(f" * #INFO: testing db connection: '{db_url}'...")
            self.db_client.server_info()
        except errors.ServerSelectionTimeoutError as e:
            raise DatabaseException(
                f"Could not connect to MongoDB at '{db_url}'")

        self.show_logs = show_logs 

def load_from_db(self, remove_invalid=True):
        """load stocks from local database only"""
        logging.info('try to load stock data from local database')
        count = 0
        try:
            for stock in self.local_dm.find_stock(show_process=True):
                self.stocks[stock.code] = stock
                count += 1
            logging.info('loaded %d stocks' % count)

            count = 0
            for index in self.local_dm.find_index():
                self.indexes[index.code] = index
                count += 1
            logging.info('loaded %d indexes' % count)
        except mongo_errors.ServerSelectionTimeoutError as e:
            logging.error("Cannot load from database, please make sure your mongodb server is running.")
            logging.error("Pymongo: %s" % str(e))
            return
        except KeyError as e:
            logging.warning('%s, please try to drop database' % str(e))
            return
        if remove_invalid:
            self._remove_unavailable_stocks() 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def connect_to_db():
    try:
        logger.info(f'Connecting to db...')
        mongo_client_location = 'db' if is_production else 'localhost'

        client = MongoClient(mongo_client_location, 27017,
                             serverSelectionTimeoutMS=max_timeout)
        client.server_info()

        logger.info(
            f'...success! Now connected to {db_name}:{collection_name}')

        db = client[db_name]
        collection = db[collection_name]

        return collection, db

    except errors.ServerSelectionTimeoutError as err:
        logger.error(
            f'... connection timed out with the db, is it running? {err}')

        return None, None 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def gather_configured_members_ips(mongo_tasks_ips, mongo_port):
    current_ips = set()
    logger = logging.getLogger(__name__)
    for t in mongo_tasks_ips:
        mc = pm.MongoClient(t, mongo_port)
        try:
            config = mc.admin.command("replSetGetConfig")['config']
            for m in config['members']:
                current_ips.add(m['host'].split(":")[0])
            # Let's accept the first configuration found. Read as room for improvement!
            break
        except ServerSelectionTimeoutError as ssete:
            logger.debug("cannot connect to {} to get configuration, failed ({})".format(t,ssete))
        except OperationFailure as of:
            logger.debug("no configuration found in node {} ({})".format(t,of))
        finally:
            mc.close()
    logger.debug("Current members in mongo configurations: {}".format(current_ips))
    return current_ips 

def get_primary_ip(tasks_ips, mongo_port):
    logger = logging.getLogger(__name__)

    primary_ips = []
    for t in tasks_ips:
        mc = pm.MongoClient(t, mongo_port)
        try:
            if mc.is_primary:
                primary_ips.append(t)
        except ServerSelectionTimeoutError as ssete:
            logger.debug("cannot connect to {} check if primary, failed ({})".format(t,ssete))
        except OperationFailure as of:
            logger.debug("no configuration found in node {} ({})".format(t,of))
        finally:
            mc.close()

    if len(primary_ips) > 1:
        logger.warning("Multiple primaries were found ({}). Let's use the first.".format(primary_ips))

    if primary_ips:
        logger.info("Primary is: {}".format(primary_ips[0]))
        return primary_ips[0] 

def select_server_by_address(self, address,
                                 server_selection_timeout=None):
        """Return a Server for "address", reconnecting if necessary.

        If the server's type is not known, request an immediate check of all
        servers. Time out after "server_selection_timeout" if the server
        cannot be reached.

        :Parameters:
          - `address`: A (host, port) pair.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value
            common.SERVER_SELECTION_TIMEOUT is used.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        return self.select_server(any_server_selector,
                                  server_selection_timeout,
                                  address) 

def setUpClass(cls):
        """
        Instantiate the adapter before any tests in the test case run.
        """
        from pymongo.errors import ServerSelectionTimeoutError
        from pymongo import MongoClient

        cls.has_mongo_connection = False

        try:
            client = MongoClient(
                serverSelectionTimeoutMS=0.1
            )
            client.server_info()

            cls.adapter = MongoDatabaseAdapter(
                database_uri='mongodb://localhost:27017/chatterbot_test_database'
            )

            cls.has_mongo_connection = False

        except ServerSelectionTimeoutError:
            pass 

def test_ServerSelectionTimeoutError_no_retry():
    error = ServerSelectionTimeoutError('some error')
    with patch('arctic.decorators._log_exception', autospec=True) as le:
        @mongo_retry
        def foo():
            raise error
        with pytest.raises(ServerSelectionTimeoutError) as e:
            foo()
    assert 'some error' in str(e.value)
    assert le.call_count == 1 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            server_descriptions = self._select_servers_loop(
                selector, server_timeout, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def _select_servers_loop(self, selector, timeout, address):
        """select_servers() guts. Hold the lock when calling this."""
        now = _time()
        end_time = now + timeout
        server_descriptions = self._description.apply_selector(
            selector, address)

        while not server_descriptions:
            # No suitable servers.
            if timeout == 0 or now > end_time:
                raise ServerSelectionTimeoutError(
                    self._error_message(selector))

            self._ensure_opened()
            self._request_check_all()

            # Release the lock and wait for the topology description to
            # change, or for a timeout. We won't miss any changes that
            # came after our most recent apply_selector call, since we've
            # held the lock until now.
            self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
            self._description.check_compatible()
            now = _time()
            server_descriptions = self._description.apply_selector(
                selector, address)

        self._description.check_compatible()
        return server_descriptions 

def check_mongo(uri=None):
    """Check if mongo db is available in the uri provided"""
    from pymongo import MongoClient
    from pymongo.errors import ServerSelectionTimeoutError
    uri = "mongodb://localhost:27019" if uri is None else uri
    client = MongoClient(uri, serverSelectionTimeoutMS=300)
    try:
        client.server_info()
        found_database = True
    except ServerSelectionTimeoutError:
        found_database = False
    return found_database 

def connect(self):
        try:
            logging.debug("Getting MongoDB connection to %s (replicaSet=%s, readPreference=%s, readPreferenceTags=%s, ssl=%s)" % (
                self.uri,
                self.replset,
                self.read_pref,
                self.do_rp_tags,
                self.do_ssl(),
            ))
            conn = MongoClient(**self.client_opts())
            if self.do_connect:
                conn['admin'].command({"ping": 1})
        except (ConfigurationError, ConnectionFailure, OperationFailure, ServerSelectionTimeoutError), e:
            logging.error("Unable to connect to %s! Error: %s" % (self.uri, e))
            raise DBConnectionError(e) 

def store():
    client = MongoClient(serverSelectionTimeoutMS=5)
    try:
        client.server_info()
    except ServerSelectionTimeoutError as err:
        print("MongoClient could not reach server, is it running ?")
        raise

    fhirstore = FHIRStore(client, DB_NAME)
    fhirstore.reset()
    fhirstore.bootstrap(depth=4, resource="Patient")
    return fhirstore 

def is_connected(self):
        try:
            self.client.server_info()
        except ServerSelectionTimeoutError:
            return False
        return True 

def setup_package():
    print(__name__, '__init__.py : setup_package() ==========================')
    try:
        testdb = MINE("mongotest")
        with open(os.path.dirname(__file__)+'/data/testing_db.json') as infile:
            jsondb = json.load(infile)
        for doc in jsondb[0]:
            testdb.compounds.save(doc)
        for doc in jsondb[1]:
            testdb.reactions.save(doc)
    except ServerSelectionTimeoutError:
        print('No Mongo DB server detected') 

def setUpClass(cls):
        from pymongo.errors import ServerSelectionTimeoutError
        from pymongo import MongoClient

        # Skip these tests if a mongo client is not running
        try:
            client = MongoClient(
                serverSelectionTimeoutMS=0.1
            )
            client.server_info()

        except ServerSelectionTimeoutError:
            raise SkipTest('Unable to connect to Mongo DB.') 

def _read_config(self):
        """Read this component's configuration from the database"""

        try:
            self.config = self.componentmodel.find_one(
                {'name': self.uniquename})
        except ServerSelectionTimeoutError:  # pragma: no cover
            self.log("No database access! Check if mongodb is running "
                     "correctly.", lvl=critical)
        if self.config:
            self.log("Configuration read.", lvl=verbose)
        else:
            self.log("No configuration found.", lvl=warn)
            # self.log(self.config) 

def create_mongo_connection(self, hostname="localhost"):
        """
            Creates a connection to YETI's MongoDB.
        :param hostname: Hostname to connect to. Default is "localhost"
        :return: None
        """

        try:
            # Try connecting to MongoDB for 10ms
            self.mongo_client = MongoClient('mongodb://{}:27017/'.format(hostname), serverSelectionTimeoutMS=10)
            self.mongo_client.server_info()
        except errors.ServerSelectionTimeoutError as mongo_conn_err:
            logger.exception(("MongoDB connection issue occurred. "
                              "Error message: " + str(mongo_conn_err)))
            sys.exit(1) 

def setUp(self):
        self.db_name = 'test_mongo_storage'
        connection_string = 'mongodb://127.0.0.1:27017/?serverSelectionTimeoutMS=100'
        try:
            self.client = Mongo(connection_string, db_name=self.db_name,
                                collection='test')
            list(self.client.get_all({}))
        except ServerSelectionTimeoutError as e:
            raise SkipTest(str(e)) 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            server_descriptions = self._select_servers_loop(
                selector, server_timeout, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def _select_servers_loop(self, selector, timeout, address):
        """select_servers() guts. Hold the lock when calling this."""
        now = _time()
        end_time = now + timeout
        server_descriptions = self._description.apply_selector(
            selector, address, custom_selector=self._settings.server_selector)

        while not server_descriptions:
            # No suitable servers.
            if timeout == 0 or now > end_time:
                raise ServerSelectionTimeoutError(
                    self._error_message(selector))

            self._ensure_opened()
            self._request_check_all()

            # Release the lock and wait for the topology description to
            # change, or for a timeout. We won't miss any changes that
            # came after our most recent apply_selector call, since we've
            # held the lock until now.
            self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
            self._description.check_compatible()
            now = _time()
            server_descriptions = self._description.apply_selector(
                selector, address,
                custom_selector=self._settings.server_selector)

        self._description.check_compatible()
        return server_descriptions 

def test_grid_in_lazy_connect(self):
        client = MongoClient('badhost', connect=False,
                             serverSelectionTimeoutMS=10)
        fs = client.db.fs
        infile = GridIn(fs, file_id=-1, chunk_size=1)
        self.assertRaises(ServerSelectionTimeoutError, infile.write, b'data')
        self.assertRaises(ServerSelectionTimeoutError, infile.close) 

def _read_config(self):
        """Read this component's configuration from the database"""

        try:
            self.config = self.componentmodel.find_one({"name": self.uniquename})
        except ServerSelectionTimeoutError:  # pragma: no cover
            self.log(
                "No database access! Check if mongodb is running " "correctly.",
                lvl=critical,
            )
        if self.config:
            self.log("Configuration read.", lvl=verbose)
        else:
            self.log("No configuration found.", lvl=warn)
            # self.log(self.config) 

def check_connection(mongo_client, host, port):
    try:
        mongo_client.server_info()
    except ServerSelectionTimeoutError as e:
        click.echo(f"Connection error while attempting to connect to {host}:{port}")
        exit(1) 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            server_descriptions = self._select_servers_loop(
                selector, server_timeout, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def _select_servers_loop(self, selector, timeout, address):
        """select_servers() guts. Hold the lock when calling this."""
        now = _time()
        end_time = now + timeout
        server_descriptions = self._description.apply_selector(
            selector, address, custom_selector=self._settings.server_selector)

        while not server_descriptions:
            # No suitable servers.
            if timeout == 0 or now > end_time:
                raise ServerSelectionTimeoutError(
                    self._error_message(selector))

            self._ensure_opened()
            self._request_check_all()

            # Release the lock and wait for the topology description to
            # change, or for a timeout. We won't miss any changes that
            # came after our most recent apply_selector call, since we've
            # held the lock until now.
            self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
            self._description.check_compatible()
            now = _time()
            server_descriptions = self._description.apply_selector(
                selector, address,
                custom_selector=self._settings.server_selector)

        self._description.check_compatible()
        return server_descriptions 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            server_descriptions = self._select_servers_loop(
                selector, server_timeout, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def _select_servers_loop(self, selector, timeout, address):
        """select_servers() guts. Hold the lock when calling this."""
        now = _time()
        end_time = now + timeout
        server_descriptions = self._description.apply_selector(
            selector, address, custom_selector=self._settings.server_selector)

        while not server_descriptions:
            # No suitable servers.
            if timeout == 0 or now > end_time:
                raise ServerSelectionTimeoutError(
                    self._error_message(selector))

            self._ensure_opened()
            self._request_check_all()

            # Release the lock and wait for the topology description to
            # change, or for a timeout. We won't miss any changes that
            # came after our most recent apply_selector call, since we've
            # held the lock until now.
            self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
            self._description.check_compatible()
            now = _time()
            server_descriptions = self._description.apply_selector(
                selector, address,
                custom_selector=self._settings.server_selector)

        self._description.check_compatible()
        return server_descriptions 

def is_db_available(self) -> bool:
        """
        check database connection
        """
        try:
            self.db_client.server_info()
            return True
        except errors.AutoReconnect or errors.ServerSelectionTimeoutError:
            return False 

def create_mongo_connection(self, hostname="localhost"):
        """
            Creates a connection to YETI's MongoDB.
        :param hostname: Hostname to connect to. Default is "localhost"
        :return: None
        """

        try:
            # Try connecting to MongoDB for 10ms
            self.mongo_client = MongoClient('mongodb://{}:27017/'.format(hostname), serverSelectionTimeoutMS=10)
            self.mongo_client.server_info()
        except errors.ServerSelectionTimeoutError as mongo_conn_err:
            logger.exception(("MongoDB connection issue occurred. "
                              "Error message: " + str(mongo_conn_err)))
            sys.exit(1) 

def catch_mongodb_error(func):
    """Catch mongodb availability error"""

    def api_wrapper(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except (ConnectionFailure, ServerSelectionTimeoutError) as e:
            raise MongoBackendError("Unable to connect to MongoDB", 500, e)

    return api_wrapper 

def save_item(self, item):
        try:
            self.collection.update({'url': item['url']}, dict(item), upsert=True)
        except ServerSelectionTimeoutError as e:
            logging.error('Fail to connect to mongodb. %s', e) 

def ensure_mongo(func):
    @wraps(func)
    def func_wrapper(*args, **kwargs):
        client = MongoClient(serverSelectionTimeoutMS=500, connectTimeoutMS=500)
        try:
             # The ismaster command is cheap and does not require auth.
            client.admin.command('ismaster')
        except (errors.ServerSelectionTimeoutError, errors.AutoReconnect):
            raise MinionMongoError("Can't connect to mongodb")
        else:
            return func(*args, **kwargs)
        finally:
            client.close()
    return func_wrapper 

def setUpClass(cls):
        from pymongo.errors import ServerSelectionTimeoutError
        from pymongo import MongoClient

        # Skip these tests if a mongo client is not running
        try:
            client = MongoClient(
                serverSelectionTimeoutMS=0.1
            )
            client.server_info()

        except ServerSelectionTimeoutError:
            raise SkipTest('Unable to connect to Mongo DB.') 

def __init__(self):

        self.client = MongoClient(serverSelectionTimeoutMS=10000)

        try:
            self.client.admin.command('ismaster')
            self.db = self.client[MONGO_DB_NAME]

            if MONGO_DB_COLLECTION in self.db.collection_names():

                self.collection = self.db[MONGO_DB_COLLECTION]
                self.connectionOK = True

        except ServerSelectionTimeoutError or ConnectionFailure:
            print("Server not available") 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._apply_selector(selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent _apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._apply_selector(selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def index(self):
        """
        Try to connect to mongo and index all the collections.
        """
        if self._db_name not in await self._client.list_database_names():
            # If the old mongo DB does not exist, use the new tenant format
            self._db_name = f"{os.environ['TENANT_ID']}#{self._db_name}"
        log.info("Selected database '%s'", self._db_name)

        self._db = self._client[self._db_name]
        # Collections
        self._workflow_templates = WorkflowTemplatesCollection(self._db)
        self._task_templates = TaskTemplatesCollection(self._db)
        self._workflow_metadata = MetadataCollection(self._db)
        self._workflow_instances = WorkflowInstancesCollection(self._db)
        self._task_instances = TaskInstancesCollection(self._db)
        self.regexes = DataProcessingCollection(self._db, 'regexes')
        self.lookups = DataProcessingCollection(self._db, 'lookups')
        self.triggers = TriggerCollection(self._db)

        log.info('Trying to connect to Mongo...')
        while True:
            try:
                await self._workflow_templates.index()
                await self._task_templates.index()
                await self._workflow_metadata.index()
                await self._workflow_instances.index()
                await self._task_instances.index()
                await self.regexes.index()
                await self.lookups.index()
                await self.triggers.index()
            except ServerSelectionTimeoutError as exc:
                log.error('Could not connect to Mongo - %s', exc)
            else:
                log.info('Successfully connected to Mongo')
                break

        if self._validate_on_start is True:
            collections = await self._db.list_collection_names()
            log.info('Validating %s collections', len(collections))
            for collection in collections:
                await self._db.validate_collection(collection)
                log.info('Validated collection %s', collection)

    # Templates 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._apply_selector(selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent _apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._apply_selector(selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._description.apply_selector(
                selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._description.apply_selector(
                    selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._description.apply_selector(
                selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._description.apply_selector(
                    selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def init(app):
    @app.errorhandler(RouteException)
    @jsonify
    def handle_route_exception(exception):
        data = {
            "error": exception.message,
            "class": exception.__class__.__name__,
            "traceback": traceback.format_tb(exception.__traceback__),
            "data": exception.data
        }
        return data, exception.status_code

    @app.errorhandler(Exception)
    @jsonify
    def handle_exception(exception):
        data = {
            "error": str(exception),
            "class": exception.__class__.__name__,
            "traceback": traceback.format_tb(exception.__traceback__),
        }
        logger.warning('general exception: ' + str_format_exception(exception))
        return data, 500

    @app.errorhandler(404)
    @jsonify
    def _page_not_found(exception):
        data = {
            "error": "Resource not found",
            "class": "PageNotFoundException",
            "traceback": traceback.format_tb(exception.__traceback__),
        }
        return data, 404

    @app.errorhandler(ValidationError)
    @jsonify
    def _validation_error(exception):
        data = {
            "error": exception.message,
            "class": "ValidationError",
            "path": list(exception.absolute_path)
        }
        return data, 400

    @app.errorhandler(ServerSelectionTimeoutError)
    @jsonify
    def _mongo_connect_error(exception):
        data = {
            "error": "Couldn't connect to Mongo database: " + str(exception),
            "class": "ServerSelectionTimeoutError",
        }
        logger.error('Could not connect to Mongo')
        return data, 500 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._description.apply_selector(
                selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._description.apply_selector(
                    selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._description.apply_selector(
                selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._description.apply_selector(
                    selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions] 

def select_servers(self,
                       selector,
                       server_selection_timeout=None,
                       address=None):
        """Return a list of Servers matching selector, or time out.

        :Parameters:
          - `selector`: function that takes a list of Servers and returns
            a subset of them.
          - `server_selection_timeout` (optional): maximum seconds to wait.
            If not provided, the default value common.SERVER_SELECTION_TIMEOUT
            is used.
          - `address`: optional server address to select.

        Calls self.open() if needed.

        Raises exc:`ServerSelectionTimeoutError` after
        `server_selection_timeout` if no matching servers are found.
        """
        if server_selection_timeout is None:
            server_timeout = self._settings.server_selection_timeout
        else:
            server_timeout = server_selection_timeout

        with self._lock:
            self._description.check_compatible()

            now = _time()
            end_time = now + server_timeout
            server_descriptions = self._apply_selector(selector, address)

            while not server_descriptions:
                # No suitable servers.
                if server_timeout == 0 or now > end_time:
                    raise ServerSelectionTimeoutError(
                        self._error_message(selector))

                self._ensure_opened()
                self._request_check_all()

                # Release the lock and wait for the topology description to
                # change, or for a timeout. We won't miss any changes that
                # came after our most recent _apply_selector call, since we've
                # held the lock until now.
                self._condition.wait(common.MIN_HEARTBEAT_INTERVAL)
                self._description.check_compatible()
                now = _time()
                server_descriptions = self._apply_selector(selector, address)

            return [self.get_server_by_address(sd.address)
                    for sd in server_descriptions]