Hi all -- thank you for including me on this thread, although I have little substantive to add. At the moment, my sole focus is finishing a journal paper about GF implementations, with a concomitant GF-complete release to accompany it. I agree that the CPU burden of the GF arithmetic will not be a bottleneck in your system, regardless of which implementation you use, as long as you stay at or below GF(2^16). If you want to go higher, GF-complete will help. When we put out a new release (the code will be ready within two weeks, however, the documentation is lagging), I'll let you know. I think LRC is a nice coding paradigm, although I imagine that it has IP issues with Microsoft. I don't have first-hand experience with network/regenerating codes, and I'll be honest -- there have been so many papers in that realm that I am not up to date on them. Is there a question on which you'd like some help? It sounds as though you are at two decision points: What code should you use, and at which point on the space-overhead/fault-tolerance curve would you like to be? Best wishes, Jim ---------- On Jun 18, 2013, at 3:44 AM, Benoît Parrein wrote: > Hi Paul, > > thank you for your message > > from my point, LRC focuses on the repairing problem. how to reconstruct destroyed node to maintain the same availability by the distributed system? > in this context they can even go below 1x rate by introducing local parity on classical Reed Solomon blocks (but they pay a supplementary overhead). see excellent Alex Dimakis's papers for that. but, still from my point, the same relationship between redundancy and availability occurs (if you consider binomial model for your loses). > > best > bp > > > Le 17/06/2013 18:55, Paul Von-Stamwitz a écrit : >> Loic, >> >> As Benoit points out, Mojette uses discrete geometry rather than algebra, so simple XOR is all that is needed. >> >> Benoit, >> >> Microsoft's paper states that their [12,2,2] LRC provides better availability than 3x replication with 1.33x efficiency. 1.5x is certainly a good number. I'm just pointing out that better efficiency can be had without losing availibity. >> >> All the best, >> Paul > > <benoit_parrein.vcf> -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
