CODEWITHSUNDEEP
snowflake-cloud-data-platform
xyz
xyz

Reputation: 37

DEBUG:snowflake.connector.connection:Rest object has been destroyed, cannot close session

Can some one please explain the technicality behind: "DEBUG:snowflake.connector.connection:Rest object has been destroyed, cannot close session"

The following Python was executed successfully:

try:
    time_start = pd.Timestamp.now()
    connection.execute(SQL)
    df = pd.read_sql_query(SQL, engine)
    time_end = pd.Timestamp.now()
    timer = pd.Timedelta(time_end-time_start).microseconds/1000
    print(timer)
except ProgrammingError as e:
    if e.errno == 604:
        print("timeout")
        connection.cursor().execute("rollback")
    else:
        raise e
else:
    connection.cursor().execute("commit")
finally:
    connection.close()
    engine.dispose()
    logging.debug('-------- Finished --------' )
    if to_csv:
        col_names = df.columns.tolist()
        if col_names_upper:
            col_names = [x.upper() for x in col_names]
        csv_file_name = 'data.csv'
        csv_path = os.path.join(dir_path,csv_file_name)
        if append:
            mode='a'
        else:
            mode='w'
        df.to_csv(csv_path,index=False, mode=mode, header=col_names)
        return None
    else:
        return df.to_dict()

But when I checked the log file, I found the following at the end of the log:

DEBUG:snowflake.connector.network:SUCCESS

DEBUG:snowflake.connector.network:Active requests sessions: 0, idle: 4

DEBUG:snowflake.connector.network:ret[code] = None, after post request

DEBUG:snowflake.connector.connection:Session is closed

DEBUG:root:-------- Finished --------

DEBUG:snowflake.connector.connection:Rest object has been destroyed, cannot close session

DEBUG:snowflake.connector.connection:Rest object has been destroyed, cannot close session

I don't understand what it meant by:"DEBUG:snowflake.connector.connection:Rest object has been destroyed, cannot close session".

Upvotes: 1

Views: 736

Answers (1)

user13472370
user13472370

Reputation:

The message Rest object has been destroyed, cannot close session is printed by the Snowflake Python Connector's connection object typically when it is attempted for closure multiple times.

This is normal to observe when using a connection pool manager: The SQLAlchemy-based engine object will attempt to close all managed connection objects when engine.dispose() is called), and also due to Python's internal garbage collection that calls connection.__del__() on objects reaching zero reference counts.

The logger level for the message is intentionally DEBUG to not worry users about successive attempts at connection cleanup by the runtime and frameworks in use. It is safe to ignore this message as it appears after the connection was closed up successfully (indicated via the Session is closed message preceding it).

Upvotes: 1

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