bug: Task exception was never retrieved (BadSession: Session not found)

[vladkolotvin]

Bug Report

YDB Python SDK version:

3.18.17

Environment

python 3.12.16
linux
x86_64

Current behavior:

Task exception was never retrieved
future: <Task finished name='Task-25851' coro=<SessionPool._send_keep_alive() done, defined at /usr/local/lib/python3.12/site-packages/ydb/aio/table.py:682> exception=BadSession('message: "Session not found." severity: 1 (server_code: 400100)')>

Traceback (most recent call last):
  File \"/usr/local/lib/python3.12/site-packages/ydb/aio/table.py\", line 688, in _send_keep_alive
    await session.keep_alive(self._req_settings)
  File \"/usr/local/lib/python3.12/site-packages/ydb/aio/table.py\", line 61, in keep_alive
    return await super().keep_alive(settings)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/usr/local/lib/python3.12/site-packages/ydb/aio/pool.py\", line 254, in __call__
    return await connection(
           ^^^^^^^^^^^^^^^^^
  File \"/usr/local/lib/python3.12/site-packages/ydb/aio/connection.py\", line 195, in __call__
    return response if wrap_result is None else wrap_result(rpc_state, response, *wrap_args)
                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/usr/local/lib/python3.12/site-packages/ydb/_session_impl.py\", line 20, in decorator
    return func(rpc_state, response_pb, session_state, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File \"/usr/local/lib/python3.12/site-packages/ydb/_session_impl.py\", line 237, in wrap_keep_alive_response
    issues._process_response(response_pb.operation)
  File \"/usr/local/lib/python3.12/site-packages/ydb/issues.py\", line 226, in _process_response
    raise exc_obj(_format_response(response_proto), response_proto.issues)
    ydb.issues.BadSession: message: \"Session not found.\" severity: 1 (server_code: 400100)

Expected behavior:

Task exception is retrieved

Steps to reproduce:

This is some floating bug

[vgvoleg]

Hi! Can you add more details? BasSession is fine to appear time to time, when server reconnect happens. Can you tell about client side behavior and server side behavior during this error?

[vladkolotvin]

It's not fine, when task result is not retrieved. It follows that the library may not handle this error.