On Sun, Mar 28, 2010 at 11:30 PM, Rainer Heilke <rheilke at dragonhearth.com> wrote: > Congrats on the OGB seat.
Thanks. I think... > Good work on the tool. I haven't explored it properly yet, but it sounds > good. I think the idea of getting everything automatically is great. We > often find we need to examine a problem using X stats. "Oh, wait. We don't > collect X." "Add X then, and hope the problem happens again." -- Seems a > little backwards. Indeed. Wouldn't it have been nice to have that data all along? (Fishworks just accumulates everything for the same reason, I think.) I've written a little app to summarize some of the properties of the accumulated statistics. On my desktop development machine over this evening: Total kstats: 713 Total statistics: 15076 Numeric statistics: 14816 String statistics: 260 Statistics zero: 8331 Statistics Changed: 2476 Kstats changed: 262 What that tells you is that most of the data is always zero. Then about half as much is non-zero but static. Only half of that again actually contains interesting data. So only about 1/3 of the kstats and 1/7 of the statistics are interesting. The others could be optimized out of the history. (That's still several thousand potentially interesting statistics, though.) > I think having a simple mechanism to map disks would be very good. Too many > times, I had to do this manually to find what was really going on. The question is how to do that. One way would be to fake up a bunch of kstats (maybe emulate the mntinfo kstats that nfs generates) that get saved the same way as the rest. It's definitely cheating, but it has the advantage of being in-band, as it were. -- -Peter Tribble http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/
