jayakrishnan mm
2016-Feb-17 04:12 UTC
[Gluster-users] disperse volume and its relation to xlators/cluster/ec
Dear Xavier, I am trying to understand the disperse translator and its usage. From https://lists.gnu.org/archive/html/gluster-devel/2014-01/txttzloLYIJOh.txt , I see there are four components namely gfsys,dfc,ida and heal which needs to be compiled with GlusterFS main source code. I am confused this with xlator/cluster/ec. What is the relationship between this and the disperse volume components mentioned earlier ? Is xlator/cluster/ec is erasure coding (ec) translator implementation in glusterFS ? If yes, which algorithm it implements ? ( I know disperse volume implements IDA) Pls. help Best Regards JK -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20160217/f0b80b34/attachment.html>
Pranith Kumar Karampuri
2016-Feb-17 05:23 UTC
[Gluster-users] disperse volume and its relation to xlators/cluster/ec
On 02/17/2016 09:42 AM, jayakrishnan mm wrote:> Dear Xavier, > > I am trying to understand the disperse translator and its usage. > > From > https://lists.gnu.org/archive/html/gluster-devel/2014-01/txttzloLYIJOh.txt > , I see there are four components namely gfsys,dfc,ida and heal > which needs to be compiled with GlusterFS main source code. > I am confused this with xlator/cluster/ec. What is the > relationship between this and the disperse volume components > mentioned earlier ? > Is xlator/cluster/ec is erasure coding (ec) translator > implementation in glusterFS ? If yes, which algorithm it implements ? > ( I know disperse volume implements IDA) > Pls. helphi Jayakrishnan, While Xavi replies to this mail, here are my inputs. I am not very familiar with the old code because I didn't get a chance to look at them deeply. But I do know about dfc. All the code of disperse volume is in 'xlators/cluster/ec'. At the moment EC is using synchronization similar to afr for now, so dfc is not in upstream yet. Heal in ec is also changed similar to afr and is done automatically by glustershd, so the functionality of 'heal' I think is implemented in ec-heal.c(Healing), ec-heald.c (automatic healing part). Did I get that right Xavi? Pranith> > Best Regards > JK > > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://www.gluster.org/mailman/listinfo/gluster-users-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20160217/146f5c66/attachment.html>
Xavier Hernandez
2016-Feb-17 07:35 UTC
[Gluster-users] disperse volume and its relation to xlators/cluster/ec
Hi jayakrishnan, the old implementation was not finally accepted to be included in main glusterfs tree, so it was rewritten in what now is known as ec. disperse is an alias for ec. They are the same. The algorithm implemented is Reed-Solomon. It's really similar to ida (we could say that ida is a specific implementation of a Reed-Solomon code). Almost all basic functionality in old code is implemented in new ec in some way, though not using the same approaches. Anyway the latest implementation is way more stable and maintained, while the old code has been abandoned and should not be used. Regards, Xavi On 17/02/16 05:12, jayakrishnan mm wrote:> Dear Xavier, > > I am trying to understand the disperse translator and its usage. > > From > https://lists.gnu.org/archive/html/gluster-devel/2014-01/txttzloLYIJOh.txt > , I see there are four components namely gfsys,dfc,ida and heal > which needs to be compiled with GlusterFS main source code. > I am confused this with xlator/cluster/ec. What is the relationship > between this and the disperse volume components mentioned earlier ? > Is xlator/cluster/ec is erasure coding (ec) translator > implementation in glusterFS ? If yes, which algorithm it implements ? ( > I know disperse volume implements IDA) > Pls. help > > Best Regards > JK