I'm encountering an error here about unable to perform operation on <TCPTransport closed=True reading=False 0x55709d84a6c0>.
This error normally doesn't occur in my project. it only occurs when server has not been active for a period of 8-12 hours. I'm using sqlalchemy orm with AsyncSession and mysql database and gunicorn with 1 uvicorn worker and fastapi .
error log:
ERROR 2023-08-17 11:02:32.933 - sqlalchemy.pool.base:_finalize_fairy - Exception during reset or similar
Traceback (most recent call last):
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 1816, in close
self._close_impl(invalidate=False)
│ └ <function Session._close_impl at 0x7f1214019af0>
└ <sqlalchemy.orm.session.Session object at 0x7f120034f940>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 1858, in _close_impl
transaction.close(invalidate)
│ │ └ False
│ └ <function SessionTransaction.close at 0x7f12140175e0>
└ <sqlalchemy.orm.session.SessionTransaction object at 0x7f120034f910>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/orm/session.py", line 928, in close
connection.close()
│ └ <function Connection.close at 0x7f12140f5ca0>
└ <sqlalchemy.future.engine.Connection object at 0x7f120034f160>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/future/engine.py", line 246, in close
super(Connection, self).close()
│ └ <sqlalchemy.future.engine.Connection object at 0x7f120034f160>
└ <class 'sqlalchemy.future.engine.Connection'>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/engine/base.py", line 1251, in close
conn.close()
│ └ <function _ConnectionFairy.close at 0x7f12144edaf0>
└ <sqlalchemy.pool.base._ConnectionFairy object at 0x7f120034f190>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/pool/base.py", line 1166, in close
self._checkin()
│ └ <function _ConnectionFairy._checkin at 0x7f12144ed550>
└ <sqlalchemy.pool.base._ConnectionFairy object at 0x7f120034f190>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/pool/base.py", line 1008, in _checkin
_finalize_fairy(
└ <function _finalize_fairy at 0x7f12144d7670>
> File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/pool/base.py", line 763, in _finalize_fairy
fairy._reset(pool, transaction_was_reset)
│ │ │ └ False
│ │ └ <sqlalchemy.pool.impl.AsyncAdaptedQueuePool object at 0x7f12133e1ac0>
│ └ <function _ConnectionFairy._reset at 0x7f12144ed5e0>
└ <sqlalchemy.pool.base._ConnectionFairy object at 0x7f120034f190>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/pool/base.py", line 1038, in _reset
pool._dialect.do_rollback(self)
│ │ │ └ <sqlalchemy.pool.base._ConnectionFairy object at 0x7f120034f190>
│ │ └ <function DefaultDialect.do_rollback at 0x7f12141f6af0>
│ └ <sqlalchemy.dialects.mysql.aiomysql.MySQLDialect_aiomysql object at 0x7f12133d1a30>
└ <sqlalchemy.pool.impl.AsyncAdaptedQueuePool object at 0x7f12133e1ac0>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/engine/default.py", line 683, in do_rollback
dbapi_connection.rollback()
└ <sqlalchemy.pool.base._ConnectionFairy object at 0x7f120034f190>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/dialects/mysql/aiomysql.py", line 205, in rollback
self.await_(self._connection.rollback())
│ │ │ └ <member '_connection' of 'AsyncAdapt_aiomysql_connection' objects>
│ │ └ <AdaptedConnection <aiomysql.connection.Connection object at 0x7f1200440550>>
│ └ <staticmethod object at 0x7f121335fd30>
└ <AdaptedConnection <aiomysql.connection.Connection object at 0x7f1200440550>>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/util/_concurrency_py3k.py", line 68, in await_only
return current.driver.switch(awaitable)
│ │ │ └ <coroutine object Connection.rollback at 0x7f11e6e824c0>
│ │ └ <method 'switch' of 'greenlet.greenlet' objects>
│ └ <greenlet.greenlet object at 0x7f1214cb8d00 (otid=0x7f1214efe2a0) suspended active started main>
└ <_AsyncIoGreenlet object at 0x7f1200467040 (otid=0x7f1214efe2a0) current active started>
File "/src/.venv/lib/python3.9/site-packages/sqlalchemy/util/_concurrency_py3k.py", line 121, in greenlet_spawn
value = await result
└ <coroutine object Connection.rollback at 0x7f11e6e824c0>
File "/src/.venv/lib/python3.9/site-packages/aiomysql/connection.py", line 357, in rollback
await self._execute_command(COMMAND.COM_QUERY, "ROLLBACK")
│ │ │ └ 3
│ │ └ <module 'pymysql.constants.COMMAND' from '/src/.venv/lib/python3.9/site-packages/pymysql/constants/COMMAND.py'>
│ └ <function Connection._execute_command at 0x7f12133035e0>
└ <aiomysql.connection.Connection object at 0x7f1200440550>
File "/src/.venv/lib/python3.9/site-packages/aiomysql/connection.py", line 661, in _execute_command
self._write_bytes(prelude + sql[:chunk_size - 1])
│ │ │ │ └ 9
│ │ │ └ b'ROLLBACK'
│ │ └ b'\t\x00\x00\x00\x03'
│ └ <function Connection._write_bytes at 0x7f1213303310>
└ <aiomysql.connection.Connection object at 0x7f1200440550>
File "/src/.venv/lib/python3.9/site-packages/aiomysql/connection.py", line 606, in _write_bytes
return self._writer.write(data)
│ │ │ └ b'\t\x00\x00\x00\x03ROLLBACK'
│ │ └ <function StreamWriter.write at 0x7f121716dc10>
│ └ <StreamWriter transport=<TCPTransport closed=True reading=False 0x55709d84a6c0> reader=<StreamReader 141 bytes eof exception=...
└ <aiomysql.connection.Connection object at 0x7f1200440550>
File "/usr/local/lib/python3.9/asyncio/streams.py", line 341, in write
self._transport.write(data)
│ │ │ └ b'\t\x00\x00\x00\x03ROLLBACK'
│ │ └ <method 'write' of 'uvloop.loop.UVStream' objects>
│ └ <TCPTransport closed=True reading=False 0x55709d84a6c0>
└ <StreamWriter transport=<TCPTransport closed=True reading=False 0x55709d84a6c0> reader=<StreamReader 141 bytes eof exception=...
File "uvloop/handles/stream.pyx", line 674, in uvloop.loop.UVStream.write
self._ensure_alive()
File "uvloop/handles/handle.pyx", line 159, in uvloop.loop.UVHandle._ensure_alive
raise RuntimeError(
RuntimeError: unable to perform operation on <TCPTransport closed=True reading=False 0x55709d84a6c0>; the handler is closed
sqlalchemy version: SQLAlchemy 1.4.49
aiomysql version: aiomysql 0.0.22
pymysql version: pymysql 0.9.3
I even activated pool_pre_ping config to check stale sessions but it resulted in some major errors with some queries that never occurred before. so I deactivated it.
now i'm stuck. I don't know what's the reason of this error.
any insight to help on this issue?