> From: Ross Boylan <[EMAIL PROTECTED]> > > In answer to the other question about using OS checkpointing > facilities, I haven't tried them since the application will be running > on a cluster. More precisely, the optimization will be driven from a > single machine, but the calculation of the objective function will be > distributed. So checkpointing at the level of the optimization > function is a good fit to my needs. There are some cluster OS's that > provide a kind of unified process space across the processors (scyld, > mosix), but we're not using them and checkpointing them is an unsolved > problem. At least, it was unsolved a couple of years ago when I > looked into it. >
A few years ago, Condor, yet another job queuing tool, had some checkpointing features. Jun Yan had a presentation on his WWW site at that time about it (but not necessarily about testing the checkpointing feature). I'd think that checkpointing would be best in system-space, not user-space; however, for optimization, it should be just a matter of saving state and possibly history, if you are doing memoization. best, -tony [EMAIL PROTECTED] Muttenz, Switzerland. "Commit early,commit often, and commit in a repository from which we can easily roll-back your mistakes" (AJR, 4Jan05). ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
