Hi Mike, Thanks for replying. The code snipped as mentioned before is - try: obj = Obj() session.add(obj) session.commit() -> this will take a lot of time in some cases (since we have a trigger on insert of this entity which is suboptimal for certain use cases) except Exception as e: session.rollback() logger.exception(e) raise e
Unfortunately before we log the exception trace, we do session.rollback() which leads to a simple AssertionError on the line "*assert self._is_transaction_boundary" *in sqlalchemy library >From my server logs though, i can provide high level logs - "time": 1535505375696, "line": "[2018-08-29 01:16:15 +0000] [1] [CRITICAL] WORKER TIMEOUT (pid:12)", "host": "logentries-d0rqp" } "time": 1535505375698, "line": "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py:434: SAWarning: Session's state has been changed on a non-active transaction - this state will be discarded.", "host": "logentries-d0rqp" } "time": 1535505375699, "line": " \"Session's state has been changed on \"", "host": "logentries-d0rqp" } "time": 1535505375700, "line": do_create\\n db.session.rollback()\\n File \"/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/scoping.py\", line 150, in do\\n return getattr(self.registry(), name)(*args, **kwargs)\\n File \"/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py\", line 754, in rollback\\n self.transaction.rollback()\\n File \"/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py\", line 437, in rollback\\n boundary._restore_snapshot(dirty_only=boundary.nested)\\n File \"/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py\", line 273, in _restore_snapshot\\n assert self._is_transaction_boundary\\nAssertionError\\n'", "host": "logentries-d0rqp" } So this could have happened - 1. We have gunicorn worker timeout set at 30 seconds. So worker was killed by gunicorn after waiting for 30 seconds for api call to respond. 2. this may trigger some session teardown on sqlalchemy. We use Flask-SQLAlchemy==2.0 (this is just a theory, i am trying to find out documents around this) 3. some exception happened in the ongoing query because of that. (not able to find out the exception trace, since it is logged after session.rollback()) 4. a rollback in our except block then lead to this error. Hope this helps. Meanwhile, I am working on adding logs and also optimizing our trigger. Thanks Mohit On Tue, Aug 28, 2018 at 6:44 PM Mike Bayer <[email protected]> wrote: > > > On Tue, Aug 28, 2018 at 7:56 AM, Mohit Agarwal <[email protected]> > wrote: > >> I will also like to know is there anytime out setting to sql alchemy >> query because of which it is raising an exception after 30 seconds and >> going into the except block. We have not explicitly passed >> statement_timeout in our implementation. >> > > > I would need to see the complete error message you are getting so I can > google it. SQLAlchemy itself has no concept of timeouts, this is > something that happens either at the driver level or in the server side > configuration of your database. > > > > > > >> >> On Tuesday, August 28, 2018 at 5:20:39 PM UTC+5:30, Mohit Agarwal wrote: >>> >>> Hi, >>> We are seeing exceptions:AssertionError being raised when of our APIs >>> has a long running query. In code we are rolling back transaction if any >>> error is received while committing. Basically we have this general wrapper >>> >>> try: >>> session.commit() >>> except Exception as e: >>> session.rollback() >>> >> raise e >> >>> >>> >>> >>> Our sql alchemy version - 1.0.6 >>> Our database - Azure SQL (sql server) >>> >>> >>> Stack trace - >>> File "/code/api/named_location/resources.py", line 258, in >>> create_named_locations_dataclass >>> File "/code/api/named_location/operations.py", line 94, in do_create >>> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/scoping.py", >>> line 150, in do >>> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", >>> line 754, in rollback >>> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", >>> line 437, in rollback >>> File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", >>> line 273, in _restore_snapshot >>> >>> From the code it looks like it fails here - >>> def _restore_snapshot(self, dirty_only=False): >>> *assert self._is_transaction_boundary* >>> What does it mean, why rollback is failing ? >>> >>> >>> >>> Thanks >>> Mohit >>> >> -- >> SQLAlchemy - >> The Python SQL Toolkit and Object Relational Mapper >> >> http://www.sqlalchemy.org/ >> >> To post example code, please provide an MCVE: Minimal, Complete, and >> Verifiable Example. See http://stackoverflow.com/help/mcve for a full >> description. >> --- >> You received this message because you are subscribed to the Google Groups >> "sqlalchemy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/sqlalchemy. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. > -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. 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