On Thu, Sep 21, 2017 at 7:27 AM, Ergo <erg...@gmail.com> wrote: > We are using: > > mysql-connector-python==2.1.6 > SQLAlchemy==1.1.13 > > I'm getting following exception in our celery tasks, it appears to happen > when we do query.first().
what normally makes this happen is that you run a SELECT and then cursor.description is None. We use the presense of cursor.description to tell us if this result has rows to return or not and if not, we close the cursor (this autoclose otherwise occurs after you exhaust all the rows). We have seen issues with drivers in the past having this problem. Specifically we saw it using eventlet / gevent, I wrote a demonstration case at https://gist.github.com/zzzeek/b762218a5f855ec7d1c3a998fe996893. the idea there is that greenlets are being killed randomly. if a database connection is in process while this kill happens, and then gets returned to the connection pool, MySQL's protocol is casual enough that it lets you emit a new statement on the connection even though the conversation is totally broken, then you don't get the result back correctly. That specific issue however was resolved long ago in 1.1.0: https://docs.sqlalchemy.org/en/latest/changelog/changelog_11.html#change-4667b5bd5cde7049b907f70614059d00 . If Celery tasks are timing out in some way that the connection is interrupted and then re-used without a BaseException or other known MySQL disconnect exception of some kind being thrown, that might be the source of this issue. > > File points2shop/lib/tasks.py line 2362 in offer_federated_sync: > offer = Offer.get_offer(offer_id) > File points2shop/model/offer.py line 2365 in get_offer: > return offer.first() > File sqlalchemy/orm/query.py line 2755 in first: > ret = list(self[0:1]) > File sqlalchemy/orm/query.py line 2547 in __getitem__: > return list(res) > File sqlalchemy/orm/loading.py line 90 in instances: > util.raise_from_cause(err) > File sqlalchemy/util/compat.py line 203 in raise_from_cause: > reraise(type(exception), exception, tb=exc_tb, cause=cause) > File sqlalchemy/orm/loading.py line 57 in instances: > for query_entity in query._entities > File sqlalchemy/orm/query.py line 3700 in row_processor: > polymorphic_discriminator=self._polymorphic_discriminator > File sqlalchemy/orm/loading.py line 319 in _instance_processor: > getter = result._getter(col, False) > File sqlalchemy/engine/result.py line 659 in _getter: > return self._non_result(None) > File sqlalchemy/engine/result.py line 1077 in _non_result: > "This result object does not return rows. " > ResourceClosedError: This result object does not return rows. It has > been closed automatically. > > > Any common causes for this to happen? > > -- > 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 sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > 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 sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
