Sqlalchemy can't catch asynch's error #319
Description
Describe the bug
I'm trying to catch the asynch exception which raised in pre_ping
According to sqlalchemy's Doc
This should be working, but it isn't.
def handle_error(e: sa.engine.ExceptionContext):
if isinstance(e.original_exception, asynch.errors.UnexpectedPacketFromServerError):
raise sqlalchemy.exc.InvalidatePoolError(
"`asynch.errors.UnexpectedPacketFromServerError`, invalidate pool",
)
sqlalchemy.event.listen(self.engine.sync_engine, "handle_error", handle_error)This event should be caught in sqlalchemy here
try:
return self.do_ping(dbapi_connection)
except self.loaded_dbapi.Error as err:
...PEP 249 said
Error
Exception that is the base class of all other error exceptions.
You can use this to catch all errors with one single except statement.
It must be a subclass of the Python Exception class.
But in clickhouse_sqlalchemy/drivers/asynch/connector.py#L117
class Error(Exception):
passThis error does not comply with PEP 249. It's should be asynch.errors.UnexpectedPacketFromServerError
To Reproduce
Minimal piece of Python code that reproduces the problem.
import asyncio
import unittest.mock
import asynch.errors
import clickhouse_sqlalchemy.drivers.asynch.connector
import sqlalchemy as sa
import sqlalchemy.event
import sqlalchemy.exc
import sqlalchemy.ext.asyncio as saea
import logging
DSN = "clickhouse+asynch://localhost:9000"
# NOTE This is a hack to fix this issue:
# clickhouse_sqlalchemy.drivers.asynch.connector.AsyncAdapt_asynch_dbapi.Error = (
# asynch.errors.ClickHouseException
# ) # type: ignore
def failed_when_select_one(self, operation, params=None, context=None):
if operation == "SELECT 1":
raise asynch.errors.UnexpectedPacketFromServerError("Unexpected packet")
else:
return self.await_(self._execute_async(operation, params, context))
@unittest.mock.patch.object(
clickhouse_sqlalchemy.drivers.asynch.connector.AsyncAdapt_asynch_cursor,
"execute",
failed_when_select_one,
)
async def main():
engine = saea.create_async_engine(DSN, echo=True,pool_pre_ping=True)
@sqlalchemy.event.listens_for(engine.sync_engine, "handle_error")
def handle_error(e: sa.engine.ExceptionContext):
if isinstance(e.original_exception, asynch.errors.UnexpectedPacketFromServerError):
raise sqlalchemy.exc.InvalidatePoolError(
"`asynch.errors.UnexpectedPacketFromServerError`, invalidate pool",
)
for _ in range(3):
async with engine.connect() as conn:
await conn.execute(sa.text("SELECT 123"))
if __name__ == "__main__":
logging.basicConfig(level=logging.INFO)
logging.getLogger("sqlalchemy.engine").setLevel(logging.INFO)
logging.getLogger("sqlalchemy.pool").setLevel(logging.DEBUG)
asyncio.run(main())Expected behavior
The exception should be caught and handled successfully.
Versions
asynch==0.2.4
clickhouse-sqlalchemy==0.3.2
SQLAlchemy==2.0.31