Try reversing the order of your decorators:
@cache.memoize(timeout=86400)
@oauth.clientgetter
def load_client(client_id):
return DBSession.query(Client).filter_by(client_id=client_id).first()
EDIT
The problem seem to be that a Client
object is not pickle-able, while cache.memoize
relies on objects' pickle-ability. Therefor, in one case, you end up with an invalid-client error (the client object did not "survive" the picke-dump-then-pickle-load process), and in another case, with some kind of caching error which (silently) prevents the object from being cached (I'm not sure what mechanism causes this silent-handling).
In any case, it seems to me you shouldn't attempt to memoize your client object in the first place.