On 28 October 2015 at 17:03, Krutika Dhananjay <kdhananj at redhat.com> wrote:> So sharding also helps with better disk utilization in > distributed-replicated volumes for large files (like VM images). > ..There are other long-term benefits one could reap from using sharding: for> instance, for someone who might want to use tiering in VM store use-case, > having sharding will be beneficial in terms of only migrating the shards > between hot and cold tiers, as opposed to moving large files in full, even > if only a small portion of the file is changed/accessed. :) >Interesting points, thanks.> > >> Yes. So Paul Cuzner and Satheesaran who have been testing sharding here >> have reported better write performance with 512M shards. I'd be interested >> to know what you feel about performance with relatively larger shards >> (think 512M). >> > > Seq Read speeds basically tripled, and seq writes improved to the limit of > the network connection. > > > OK. And what about the data heal performance with 512M shards? > Satisfactory? >Easily satisfactory, a bit slower than the 4MB shard but still way faster than a full multi GB file heal :) Something I have noticed, is that the heal info (gluster volume heal <datastore> info) can be very slow to return, as in many 10's of seconds - is there a way to speed that up? It would be every useful if there was a command that quickly gave summary/progress status, e.g "There are <X> shards to be healed" -- Lindsay -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20151028/94b2f919/attachment.html>
----- Original Message -----> From: "Lindsay Mathieson" <lindsay.mathieson at gmail.com> > To: "Krutika Dhananjay" <kdhananj at redhat.com> > Cc: "gluster-users" <gluster-users at gluster.org> > Sent: Wednesday, October 28, 2015 1:08:33 PM > Subject: Re: [Gluster-users] Shard Volume testing (3.7.5)> On 28 October 2015 at 17:03, Krutika Dhananjay < kdhananj at redhat.com > wrote:> > So sharding also helps with better disk utilization in > > distributed-replicated > > volumes for large files (like VM images). > > > .. > > > There are other long-term benefits one could reap from using sharding: for > > instance, for someone who might want to use tiering in VM store use-case, > > having sharding will be beneficial in terms of only migrating the shards > > between hot and cold tiers, as opposed to moving large files in full, even > > if only a small portion of the file is changed/accessed. :) >> Interesting points, thanks.> > > > Yes. So Paul Cuzner and Satheesaran who have been testing sharding here > > > > have > > > > reported better write performance with 512M shards. I'd be interested > > > > to > > > > know what you feel about performance with relatively larger shards > > > > (think > > > > 512M). > > > > > >> > > Seq Read speeds basically tripled, and seq writes improved to the limit > > > of > > > the network connection. > > >> > OK. And what about the data heal performance with 512M shards? > > Satisfactory? >> Easily satisfactory, a bit slower than the 4MB shard but still way faster > than a full multi GB file heal :)> Something I have noticed, is that the heal info (gluster volume heal > <datastore> info) can be very slow to return, as in many 10's of seconds - > is there a way to speed that up?With sharding? Or even otherwise? Approximately how many entries did the command list when you found it to be slow? On a related note, Anuradha (cc'd) is working on an enhancement that would make the 'heal info' reporting faster. She should be able to tell you more about it.> It would be every useful if there was a command that quickly gave > summary/progress status, e.g "There are <X> shards to be healed"Hmmm ... that would have to be an extension of 'heal info' or perhaps post-processing of the 'heal info' output which would group the different shards of a given file that need heal together. Nice suggestion. I will think about it. -Krutika> -- > Lindsay-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20151028/661c0a5b/attachment.html>
----- Original Message -----> From: "Lindsay Mathieson" <lindsay.mathieson at gmail.com> > To: "Krutika Dhananjay" <kdhananj at redhat.com> > Cc: "gluster-users" <gluster-users at gluster.org> > Sent: Wednesday, October 28, 2015 1:08:33 PM > Subject: Re: [Gluster-users] Shard Volume testing (3.7.5) > > > On 28 October 2015 at 17:03, Krutika Dhananjay < kdhananj at redhat.com > wrote: > > > > So sharding also helps with better disk utilization in distributed-replicated > volumes for large files (like VM images). > .. > > There are other long-term benefits one could reap from using sharding: for > instance, for someone who might want to use tiering in VM store use-case, > having sharding will be beneficial in terms of only migrating the shards > between hot and cold tiers, as opposed to moving large files in full, even > if only a small portion of the file is changed/accessed. :) > > > Interesting points, thanks. > > > > > > > > > > > Yes. So Paul Cuzner and Satheesaran who have been testing sharding here have > reported better write performance with 512M shards. I'd be interested to > know what you feel about performance with relatively larger shards (think > 512M). > > Seq Read speeds basically tripled, and seq writes improved to the limit of > the network connection. > > OK. And what about the data heal performance with 512M shards? Satisfactory? > > > Easily satisfactory, a bit slower than the 4MB shard but still way faster > than a full multi GB file heal :) > > > Something I have noticed, is that the heal info (gluster volume heal > <datastore> info) can be very slow to return, as in many 10's of seconds - > is there a way to speed that up? >Yes, there is a way to speed it up. Basically the process of finding out whether a file needs heal or not takes some time, leading to slow heal info. This decision making can be done in a faster way. I'm working on the approach and will send a patch in the coming days.> It would be every useful if there was a command that quickly gave > summary/progress status, e.g "There are <X> shards to be healed" > > > -- > Lindsay > > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://www.gluster.org/mailman/listinfo/gluster-users-- Thanks, Anuradha.