def __connect(self):
mongo_url = self.__get_mongo_url(self.settings_dict)
logger.debug("Connecting to '%s'..." % self.displayed_mongo_url)
conn_cnt = 0
while conn_cnt < settings.DB_CONN_MAX_TIMES:
try:
# More details about `MongoClient` API, see:
# https://api.mongodb.com/python/2.8/api/pymongo/mongo_client.html#pymongo.mongo_client.MongoClient
client = MongoClient(mongo_url)
# the constructor returns immediately and launches the
# connection process on background threads.
# Checks if the server is available like this:
client.admin.command('ismaster')
logger.debug("Connection to MongoDB is established.")
return client
# If auto-reconnection will be performed, AutoReconnect will be raised.
# Application code should handle this exception (recognizing that the
# operation failed) and then continue to execute.
except errors.AutoReconnect as e:
conn_cnt += 1
msg = ("Connection to MongoDB is lost and an attempt to "
"auto-connect will be made ...")
stdout.warn(msg)
logger.warning(msg)
logger.error("Unable to establish the connection to MongoDB.")
raise ImproperlyConfigured(
"Unable to establish the connection to MongoDB.")
def get_connection(self, settings_dict):
if settings_dict.get('HOST') and settings_dict.get('PORT'):
stdout.debug(
"Trying to connect to {} servered on '{}:{}'...".format(
self.db_name, settings_dict['HOST'],
settings_dict['PORT']))
conn_cnt = 0
while conn_cnt < settings.DB_CONN_MAX_TIMES:
try:
conn = self._connect(settings_dict)
stdout.success("Connection to {} established.".format(
self.db_name))
return conn
except ConnectionTimeout as e:
conn_cnt += 1
interval = random.randint(0, settings.DB_CONN_MAX_INTERVAL)
stdout.warn(
"Connection timeout to {}: {}\nWill retry to connect in {} \
seconds.".format(self.db_name, str(e), interval))
time.sleep(interval)
except KeyError as e:
# May raise when resolving the settings dict
stdout.error("Fields missing, check '{}' was set.".format(
str(e)))
raise ImproperlyConfigured("Fields missing: {}".format(str(e)))
stdout.error("Unable to establish connection to '{}'".format(
self.db_name))
raise ImproperlyConfigured()
def _connect(self, settings_dict):
try:
conn = mysqldb.connect(host=settings_dict['HOST'],
port=settings_dict['PORT'],
user=settings_dict['USER'],
passwd=settings_dict['PASSWORD'],
db=settings_dict['DATABASE'],
charset=settings_dict['CHARSET'],
connect_timeout=settings.DB_CONN_TIMEOUT)
except (mysqldb.InternalError, mysqldb.OperationalError) as e:
stdout.warn(str(e))
raise ConnectionTimeout
return conn
def _connect(self, settings_dict):
try:
conn = _mssql.connect(server=settings_dict['HOST'],
port=settings_dict['PORT'],
user=settings_dict['USER'],
password=settings_dict['PASSWORD'],
database=settings_dict['DATABASE'],
charset=settings_dict['CHARSET'])
conn.query_timeout = settings.DB_CONN_TIMEOUT
# _mssql is not written based on the PEP-249, `exceptions` on _mssql see:
# http://pymssql.org/en/stable/ref/_mssql.html#module-level-exceptions
except _mssql.MssqlDatabaseException as e:
stdout.warn(str(e))
raise ConnectionTimeout
return conn
def _connect(self, settings_dict):
try:
conn = pymssql.connect(
host=settings_dict['HOST'],
port=settings_dict['PORT'],
user=settings_dict['USER'],
password=settings_dict['PASSWORD'],
database=settings_dict['DATABASE'],
charset=settings_dict['CHARSET'],
timeout=settings.DB_CONN_TIMEOUT,
)
# More details on error of python database api, see ref:
# https://www.python.org/dev/peps/pep-0249/
except (pymssql.InternalError, pymssql.OperationalError) as e:
stdout.warn(str(e))
raise ConnectionTimeout
return conn