On Jul 25, 2010, at 6:10 AM, Eran Sandler wrote: > Hello all, > > I'm using SqlSoup with PyODBC to access MSSQL under Tornado (without > using process forks). > > Since tornado is an event based server, I create the SqlSoup object at > the application init and use it when I get various requests. > I keep on seeing an increase of memory related to SqlSoup and > SqlAlchemy. > > At first, I thought it was due to the fact that SqlSoup always uses a > Session and since I never create or delete session it may cause this > problem. I therefore added calls after each request such as: > > db.commit() > db.expunge_all() > db.session.close() > > However it doesn't seem to be helping much. > > The dictionaries that seems to be increasing in size are: > dict of sqlalchemy.orm.attributes.ScalarAttributeImpl > dict of sqlalchemy.orm.properties.ColumnProperty > dict of sqlalchemy.orm.strategies.ColumnLoader
Those are objects that correspond to a class that is mapped. SQLSoup creates classes dynamically and then maps them anytime you say sqlsoup.<somename> - a class called <somename> and a corresponding Table are created, columns loaded from the database, and you get the mapped class back. The structure is then stored within the SQLSoup instance and returned again upon subsequent access. So if you were loading an arbitrarily large set of distinctly named tables from your SQLSoup, or if you had an arbitrarily growing collection of SQLSoup instances themselves, you would see unbounded growth in class-mapping artifacts. Nothing is strongly referenced at the module level so even if you created SQLSoup instances constantly and lost references to them, while such a scheme would perform horribly and obliterate any advantage gained by Tornado, it still shouldn't leak memory. You might want to peek inside of sqlsoup._cache and see if that is growing for some reason. -- 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.
