Written by [EMAIL PROTECTED] on 06/30/08 12:58>> >>>> In 6.x. the default thread library is quite inefficient although it >>>> can make use of multiple CPUs (again, providing the application is >>>> giving them work to do). For multi-threaded performance you will be >>>> better off switching to the libthr library (see libmap.conf(5)) or >>>> updating to 7.0 (where it is the default). This isn't likely to be >>>> the underlying issue if you are trying to debug a loss of >>>> performance relative to the same configuration in the past though. >>> >>> Indeed Plone is written in python, and python has a "Big Giant Lock" >>> inside which insures that only one thread can execute, in order to >>> protect the python structures. This lock is only released under special >>> circumstances, such as doing IO. Hence it is necessary to run several >>> instances of python programs and do synchronization work, if one wants >>> to make use of several CPUs, or use python threads, and immediately >>> make some IOs, or similar techniques. It may be that using Jython, if >>> possible, yields better threading behavior. When doing some work >>> according to these ideas, i had found quite severe contention, and this >>> was not cured when switching native threading libraries (libksd, libthr, >>> etc.). The problem is really inside python. >> >> Yep, it could be that -- what confuses me though is that it is claimed >> that performance suddenly regressed. If so then this cannot be the >> underlying cause. >> > > It's actually been a long, slow, steady degradation of performance as > best I can tell, that's recently just reached proportions that are so > ridiculous that it's gone from "this sucks but I can deal" to "this is > completely unusable." The system has been slow from the start, just not > this slow. I guess I'll need to investigate this...and while I know that > Python is somewhat off-topic, if anyone here has any suggestions on > where to start, they'd be much appreciated. :-) > > Alex
As far as degradations-over-time are concerned, don't overlook your ZODB. If you don't pack it regularly and it grows to some ridiculous size you can be in for a world of hurt. _______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"