On Nov 3, 2010, at 10:11 AM, Michael Bayer wrote: > > On Nov 2, 2010, at 11:46 PM, Warwick Prince wrote: > >> Hi Michael >> >> I have an issue I can't fathom regarding Pools. I'm doing testing and hit >> the following error at exatly the same point each time; >> >> File "C:\Documents and Settings\wprince\Desktop\PY CODE >> DEVELOPMENT\pyDAP\DAPForm.py", line 3805, in _processQuery >> self._queryCount = self._query.count() >> File "C:\Python26\lib\site-packages\sqlalchemy\orm\query.py", line 1888, >> in count >> should_nest = should_nest[0] >> File "C:\Python26\lib\site-packages\sqlalchemy\orm\query.py", line 1924, >> in _col_aggregate >> mapper=self._mapper_zero()) >> File "C:\Python26\lib\site-packages\sqlalchemy\orm\session.py", line 740, >> in scalar >> return self.execute(clause, params=params, mapper=mapper, **kw).scalar() >> File "C:\Python26\lib\site-packages\sqlalchemy\orm\session.py", line 734, >> in execute >> return self._connection_for_bind(engine, close_with_result=True).execute( >> TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection >> timed out, timeout 30 >> >> I'm creating a basic "create_engine" using defaults for the pool settings >> (as you can tell). Within each Thread that does the connection, I create a >> new engine, metadata and scoped session. That thread then does a basic >> query (in this case NOT using a session at all, just a direct table query) >> and then I do everything I can think of to close the connections. I do >> this; >> >> engine.dispose() >> session.commit() >> session.close() >> >> and then the class instance that holds all these is removed and the thread >> terminates. All works fine (i.e. no errors or exceptions) until I reach >> the 10 overflow limit and then it dies. Each destroy of an engine and >> recreate of an engine is at least a second apart so it's not being thrashed >> at all. >> >> What am I missing? > > The error is local to a single engine. So engine.dispose() has no impact on > the issue.
well, correction, yes if you dispose the engine the pool drops away and is replaced with another, but that doesn't solve the core issue of using connections and not closing them out, since dispose() does not impact connections which are checked out. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
