ResourceWarning: unclosed socket

[BayerSe]

Hi,

running the following script with pytest such that it raises warnings, pytest -Werror test.py, raises an error on my machine:

import oracledb

user ="..."
password = "..."
dsn = "..."

def test_oracledb() -> None:
    with oracledb.connect(user=user, password=password, dsn=dsn) as connection:
        with connection.cursor() as cursor:
            cursor.execute("SELECT 1 FROM DUAL")

This is the error:

================================================================================================ test session starts ================================================================================================
platform linux -- Python 3.10.9, pytest-7.2.1, pluggy-1.0.0
rootdir: /home/user/PycharmProjects/project/tests
plugins: time-machine-2.9.0, dotenv-0.5.2, cov-4.0.0, mock-3.10.0
collected 1 item

test.py F                                                                                                                                                                                                     [100%]

===================================================================================================== FAILURES ======================================================================================================
___________________________________________________________________________________________________ test_oracledb ___________________________________________________________________________________________________

cls = <class '_pytest.runner.CallInfo'>, func = <function call_runtest_hook.<locals>.<lambda> at 0x7f57d5f61090>, when = 'call', reraise = (<class '_pytest.outcomes.Exit'>, <class 'KeyboardInterrupt'>)

    @classmethod
    def from_call(
        cls,
        func: "Callable[[], TResult]",
        when: "Literal['collect', 'setup', 'call', 'teardown']",
        reraise: Optional[
            Union[Type[BaseException], Tuple[Type[BaseException], ...]]
        ] = None,
    ) -> "CallInfo[TResult]":
        """Call func, wrapping the result in a CallInfo.

        :param func:
            The function to call. Called without arguments.
        :param when:
            The phase in which the function is called.
        :param reraise:
            Exception or exceptions that shall propagate if raised by the
            function, instead of being wrapped in the CallInfo.
        """
        excinfo = None
        start = timing.time()
        precise_start = timing.perf_counter()
        try:
>           result: Optional[TResult] = func()

../.venv/lib/python3.10/site-packages/_pytest/runner.py:339:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
../.venv/lib/python3.10/site-packages/_pytest/runner.py:260: in <lambda>
    lambda: ihook(item=item, **kwds), when=when, reraise=reraise
../.venv/lib/python3.10/site-packages/pluggy/_hooks.py:265: in __call__
    return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
../.venv/lib/python3.10/site-packages/pluggy/_manager.py:80: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
../.venv/lib/python3.10/site-packages/_pytest/unraisableexception.py:88: in pytest_runtest_call
    yield from unraisable_exception_runtest_hook()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def unraisable_exception_runtest_hook() -> Generator[None, None, None]:
        with catch_unraisable_exception() as cm:
            yield
            if cm.unraisable:
                if cm.unraisable.err_msg is not None:
                    err_msg = cm.unraisable.err_msg
                else:
                    err_msg = "Exception ignored in"
                msg = f"{err_msg}: {cm.unraisable.object!r}\n\n"
                msg += "".join(
                    traceback.format_exception(
                        cm.unraisable.exc_type,
                        cm.unraisable.exc_value,
                        cm.unraisable.exc_traceback,
                    )
                )
>               warnings.warn(pytest.PytestUnraisableExceptionWarning(msg))
E               pytest.PytestUnraisableExceptionWarning: Exception ignored in: <socket.socket fd=-1, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6>
E
E               Traceback (most recent call last):
E                 File "/home/user/PycharmProjects/project/.venv/lib/python3.10/site-packages/oracledb/connection.py", line 135, in __init__
E                   impl.connect(params_impl)
E               ResourceWarning: unclosed <socket.socket fd=11, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('...', ...), raddr=('...', ...)>

../.venv/lib/python3.10/site-packages/_pytest/unraisableexception.py:78: PytestUnraisableExceptionWarning
============================================================================================== short test summary info ==============================================================================================
FAILED test.py::test_oracledb - pytest.PytestUnraisableExceptionWarning: Exception ignored in: <socket.socket fd=-1, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6>
================================================================================================= 1 failed in 0.18s =================================================================================================

Am I doing anything wrong with the thin driver? I did not see this behavior with cx_Oracle.

[anthony-tuininga]

I'm not sure if you are doing something "wrong". I tried your sample code, though, and didn't receive any errors! I have, however, seen something similar in our own test suite:

1106 - connection to database with bad password ... /usr/lib64/python3.10/traceback.py:236: ResourceWarning: unclosed <socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6, laddr=('127.0.0.1', 50832), raddr=('127.0.0.1', 1521)>
  tb.tb_frame.clear()
ResourceWarning: Enable tracemalloc to get the object allocation traceback

It is on my list of things to look into when I get a chance...but I haven't noticed that it is of significant concern.

[BayerSe]

@zzzeek, this is happening on Ubuntu 20.04

@anthony-tuininga
I did some more testing. This does not happen with cx_Oracle or oracledb with the thick driver. This also does not happen when testing against a local oracle 18 xe.

So, there seems to be some mismatch between our databases and the thin driver. Any idea where to start? The precise version we are using is: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production

[anthony-tuininga]

I'm not surprised that it doesn't happen with thick mode because the socket management is buried in the Oracle Client libraries! The version you reported is incorrect. Assuming that is reported by SQL*Plus there is another line right below it that gives the full version. Or you can simply report the value of connection.version in your Python script. I'll try with a remote database and see if I am able to replicate.

[anthony-tuininga]

I tried a cloud database (version 19.18.0.1.0) and it doesn't report any errors either. :-(

[BayerSe]

Ah, I see. The precise version is 19.11.0.0.0.

[cjbj]

@BayerSe is there anything else you can alter to help narrow down the problem? Does it happen with other versions of Python? Does it happen from Windows or macOS? Do you have a more recent 19c DB available to test with (19.11 is nearly 2 years old)?