I've written a program using Twisted that uses SqlAlchemy to access a database using threads.deferToThread(...) and SqlAlchemy's scoped_session(...). This program runs for a long time, but leaks memory slowly to the point of needing to be restarted. I don't know that the SqlAlchemy/threads thing is the problem, but thought I'd make you aware of it.
Anyway, my real question is how to go about debugging memory leak problems in Python, particularly for a long running server process written with Twisted. I'm not sure how to use heapy or guppy, and objgraph doesn't tell me enough to locate the problem. If anyone as any suggestions or pointers it would be very much appreciated!