Thus spake Jo Rhett (jrh...@netconsonance.com) on Tue, Apr 12, 2011 at 02:27:23PM -0700: > From the following page we found some solutions to certain problems we were > seeing. http://net.doit.wisc.edu/~dwcarder/rrdcache/ >
Hi Jo, Here are some thoughts: - My crappy web page more or less evolved into a real paper written by actual academics which was presented at LISA '07: http://www.usenix.org/events/lisa07/tech/full_papers/plonka/plonka_html/index.html - We are now running our (even bigger) MRTG system with (16) solid-state disks in a RAID configuration, and needless to say we don't have issues with seek or read performance any more. - Take a look at rrdcached in the 1.4.x branch of code. I know this doesn't help you now, but it is where all of the development effort is going. While we aren't using this rrdcached yet, we're keeping a close eye on it as it stabilizes. - If you could move to a version of rrdtool that at least incorporates the posix fadvise calls, thay might clear up your issue or go long way towards resolving it. This would be version rrdtool-1.2.26 or better. Presumably you could port that (rather simple) change into the version that you are running and your OS "does the right thing" with this call. - As a last resort, you may be able trick your OS to evict pages from the buffer cache. See the paper, and this utility: http://net.doit.wisc.edu/~plonka/fadvise/ Cheers, Dale > This one host is using an older version of RRDtool with little chance for > upgrade due to obsolete host OS, so this seemed appealing. However playing > with the module has found it quite immature ... print() statements inside the > library, plus a number of fairly obvious bugs due to fixing a specific > problem for one application and not for all. > > Issues I've found so far: > > 1. If the application is short lived, tmp files are never renamed and > thus never used. It only works as implemented for long-running applications. > > 2. If the application saves data with "N" for the timestamp, all > updates are applied with the same timestamp. > > 3. Not all functions from RRDs.pm implemented > > 4. print() calls in the library routines > > 5. error() function commented out > > I'm sure there are more. Is anyone else using this in the wild? Want to > collaborate on fixes? > > -- > Jo Rhett > Net Consonance : consonant endings by net philanthropy, open source and other > randomness > _______________________________________________ rrd-users mailing list rrd-users@lists.oetiker.ch https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users