John Arbash Meinel wrote: […]
Just for the record, changing cleanFailure to not do its operation is likely to lead to big memory leaks. The second thing you did, setting self.tb to None, makes more sense to speed things up.
Right. I agree that it is a better solution. I was wondering about having a whitelist of Exception classes that aren't considered interesting enough to keep a traceback.
I've filed <http://twistedmatrix.com/trac/ticket/5011> about this issue, and I have a patch that takes an alternative approach: don't capture tracebacks when Deferred callbacks raise exceptions unless defer.setDebugging(True) has been called. Another possibility might be to stop Failure from capturing all the frame details (i.e. the locals and globals) by default (or at least when invoked by Deferred._runCallbacks), as that's probably the bulk of the expense and would be very rarely used. -Andrew.