Martin Phillips wrote: > I am looking for some information about the performance > impact of using the > RFS and NFA components of Unidata...... > > 1. Does anyone have experience of just how much use of RFS degrades > performance? The application concerned does not currently > use transactions > though this would be beneficial if the RFS mechanism is to > give business > level data integrity.
Martin, my problem with answering this is that while I've got plenty of experience with UniData sites that run RFS and plenty with ones that don't, I've never really had a site go from 'without' to 'with' on the same box so I could do a comparison. Clearly there is more load on the box with RFS active. Beyond this, it also seems clear that batch update operations where the WRITE to READ ratio is pretty high, and where a large portion of certain key data files gets updated can run substantially slower with RFS active. I have a large site that runs exclusively with RFS during the day, but which switches RFS off every night to do their EOD because otherwise it takes too long - maybe 50% longer than the current 3.5 hours or so. During the day however, they don't seem to have any issues with interactive response and perceived performance of reporting etc with RFS running. IBM have always said lots of guarded things about memory requirements and performance with RFS, but I've never really subscribed to that negativity. These days 4MB per user isn't actually a great deal, and I'm not sure I've seen usage that high. Certainly though, it is vital to configure RFS properly before using it in production. Under no circumstances should you just say 'Yes' to the question udtinstall asks about using RFS and leave it at that. You need to allocate log space intelligently, and you need to configure buffer sizes generously. If the client wants benefits from RFS then they need to use archiving so they have a rollforward path, and if you simply switch that on 'out of the box' you are certainly asking for trouble. Email me offline if you want more details. > 2. The same client is looking to use NFA to access files on > other systems in > a wide area network. Any information about experiences of its > performance > would be much appreciated. NFA isn't a performance hog, but you wouldn't want to do all your IO across it, and you can't cleanly have it interact with RFS - ie you can't have a transaction which updates both local and remote files. Cheers, Ken ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/
