Hi, So after some testing, it is a lot better but I do still have some problems with 3.7.11. When I reboot a server it seems to have some strange behaviour sometimes, but I need to test that better. Removing a server from the network, waiting for a while then adding it back and letting it heal works perfectly, completly invisible for the user and that's perfect ! However when I add a brick, changing the replica count from 2 to 3, it starts a heal and some VMs switch to read only. I have to power them off then on again to fix it, clearly it's better than with 3.7.6 which froze the VM until the heal was complete, but I would still like to understand why some of the VMs are switching to readonly. Looks like it happens everytime I add a brick to increase the replica, I would like to test adding a whole replica set at once but I just don't have the hardware for that. Rebooting a node looks like it's making some VMs go read only too, but I need to test that better. For some reason it looks like rebooting a brick or adding a brick is causing I/O errors on some VM disks and not others, and I have to power them off and then on to fix it. I can't just reboot them, I guess I have to actually re-open the file to trigger a heal ? Any idea on how to prevent that ? It's a lot better than 3.7.6 'cause it can be fixed in a minute, but that's still not great to explain to the clients. Thanks On Mon, Apr 25, 2016 at 02:01:09PM +0200, Kevin Lemonnier wrote: > Hi, > > So I'm trying that now. > I installed 3.7.11 on two nodes and put a few VMs on it, same config > as before but with 64MB shards and the heal algo to full. As expected, > if I poweroff one of the nodes, everything is dead, which is fine. > > Now I'm adding a third node, a big heal was started after the add-brick > of everything (7000+ shards), and for now everything seems to be working > fine on the VMs. Last time I tried adding a brick, all those VM died for > the duration of the heal, so that's already pretty good. > > I'm gonna let it finish to copy everything on the new nodes, then I'll try > to simulate nodes going down to see if my original problem of freezing and > low heal time is solved with this config. > For reference, here is the volume info, if someone sees something I should change : > > Volume Name: gluster > Type: Replicate > Volume ID: e4f01509-beaf-447d-821f-957cc5c20c0a > Status: Started > Number of Bricks: 1 x 3 = 3 > Transport-type: tcp > Bricks: > Brick1: ipvr2.client_name:/mnt/storage/gluster > Brick2: ipvr3.client_name:/mnt/storage/gluster > Brick3: ipvr50.client_name:/mnt/storage/gluster > Options Reconfigured: > cluster.quorum-type: auto > cluster.server-quorum-type: server > network.remote-dio: enable > cluster.eager-lock: enable > performance.quick-read: off > performance.read-ahead: off > performance.io-cache: off > performance.stat-prefetch: off > features.shard: on > features.shard-block-size: 64MB > cluster.data-self-heal-algorithm: full > performance.readdir-ahead: on > > > It starts at 2 and jumps to 50 because the first server is doing something else for now, > and I use 50 to be the temporary third node. If everything goes well, I'll migrate the production > on the cluster, re-install the first server and do a replace-brick, which I hope will work just as well > as the add-brick I'm doing now. Last replace-brick also brought everything down, but I guess that was the > joy of 3.7.6 :). > > Thanks ! > > > On Mon, Apr 18, 2016 at 08:17:05PM +0530, Krutika Dhananjay wrote: > > On Mon, Apr 18, 2016 at 8:02 PM, Kevin Lemonnier <lemonnierk@xxxxxxxxx> > > wrote: > > > > > I will try migrating to 3.7.10, is it considered stable yet ? > > > > > > > Oops, just realized 3.7.10 had a regression. Then 3.7.11 it is. :) > > > > > > > Should I change the self heal algorithm even if I move to 3.7.10, or is > > > that not necessary ? > > > Not sure what that change might do. > > > > > > > So the other algorithm is 'diff' which computes rolling checksum on chunks > > of the src(es) and sink(s), compares them and heals upon mismatch. This is > > known to consume lot of CPU. 'full' algo on the other hand simply copies > > the src into sink in chunks. With sharding, it shouldn't be all that bad > > copying a 256MB file (in your case) from src to sink. We've used double the > > block size and had no issues reported. > > > > So you could change self heal algo to full even in the upgraded cluster. > > > > -Krutika > > > > > > > > > > Anyway, I'll try to create a 3.7.10 cluster in the week end slowly move > > > the VMs on it then, > > > Thanks a lot for your help, > > > > > > Regards > > > > > > > > > On Mon, Apr 18, 2016 at 07:58:44PM +0530, Krutika Dhananjay wrote: > > > > Hi, > > > > > > > > Yeah, so the fuse mount log didn't convey much information. > > > > > > > > So one of the reasons heal may have taken so long (and also consumed > > > > resources) is because of a bug in self-heal where it would do heal from > > > > both source bricks in 3-way replication. With such a bug, heal would take > > > > twice the amount of time and consume resources both the times by the same > > > > amount. > > > > > > > > This issue is fixed at http://review.gluster.org/#/c/14008/ and will be > > > > available in 3.7.12. > > > > > > > > The other thing you could do is to set cluster.data-self-heal-algorithm > > > to > > > > 'full', for better heal performance and more regulated resource > > > consumption > > > > by the same. > > > > #gluster volume set <VOL> cluster.data-self-heal-algorithm full > > > > > > > > As far as sharding is concerned, some critical caching issues were fixed > > > in > > > > 3.7.7 and 3.7.8. > > > > And my guess is that the vm crash/unbootable state could be because of > > > this > > > > issue, which exists in 3.7.6. > > > > > > > > 3.7.10 saw the introduction of throttled client side heals which also > > > moves > > > > such heals to the background, which is all the more helpful for > > > preventing > > > > starvation of vms during client heal. > > > > > > > > Considering these factors, I think it would be better if you upgraded > > > your > > > > machines to 3.7.10. > > > > > > > > Do let me know if migrating to 3.7.10 solves your issues. > > > > > > > > -Krutika > > > > > > > > On Mon, Apr 18, 2016 at 12:40 PM, Kevin Lemonnier <lemonnierk@xxxxxxxxx> > > > > wrote: > > > > > > > > > Yes, but as I was saying I don't believe KVM is using a mount point, I > > > > > think it uses > > > > > the API ( > > > > > > > > http://www.gluster.org/community/documentation/index.php/Libgfapi_with_qemu_libvirt > > > > > ). > > > > > Might be mistaken ofcourse. Proxmox does have a mountpoint for > > > > > conveniance, I'll attach those > > > > > logs, hoping they contain the informations you need. They do seem to > > > > > contain a lot of errors > > > > > for the 15. > > > > > For reference, there was a disconnect of the first brick (10.10.0.1) in > > > > > the morning and then a successfull > > > > > heal that caused about 40 minutes downtime of the VMs. Right after that > > > > > heal finished (if my memory is > > > > > correct it was about noon or close) the second brick (10.10.0.2) > > > rebooted, > > > > > and that's the one I disconnected > > > > > to prevent the heal from causing another downtime. > > > > > I reconnected it one at the end of the afternoon, hoping the heal > > > would go > > > > > well but everything went down > > > > > like in the morning so I disconnected it again, and waited 11pm > > > (23:00) to > > > > > reconnect it and let it finish. > > > > > > > > > > Thanks for your help, > > > > > > > > > > > > > > > On Mon, Apr 18, 2016 at 12:28:28PM +0530, Krutika Dhananjay wrote: > > > > > > Sorry, I was referring to the glusterfs client logs. > > > > > > > > > > > > Assuming you are using FUSE mount, your log file will be in > > > > > > /var/log/glusterfs/<hyphenated-mount-point-path>.log > > > > > > > > > > > > -Krutika > > > > > > > > > > > > On Sun, Apr 17, 2016 at 9:37 PM, Kevin Lemonnier < > > > lemonnierk@xxxxxxxxx> > > > > > > wrote: > > > > > > > > > > > > > I believe Proxmox is just an interface to KVM that uses the lib, > > > so if > > > > > I'm > > > > > > > not mistaken there isn't client logs ? > > > > > > > > > > > > > > It's not the first time I have the issue, it happens on every heal > > > on > > > > > the > > > > > > > 2 clusters I have. > > > > > > > > > > > > > > I did let the heal finish that night and the VMs are working now, > > > but > > > > > it > > > > > > > is pretty scarry for future crashes or brick replacement. > > > > > > > Should I maybe lower the shard size ? Won't solve the fact that 2 > > > > > bricks > > > > > > > on 3 aren't keeping the filesystem usable but might make the > > > healing > > > > > > > quicker right ? > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > Le 17 avril 2016 17:56:37 GMT+02:00, Krutika Dhananjay < > > > > > > > kdhananj@xxxxxxxxxx> a écrit : > > > > > > > >Could you share the client logs and information about the approx > > > > > > > >time/day > > > > > > > >when you saw this issue? > > > > > > > > > > > > > > > >-Krutika > > > > > > > > > > > > > > > >On Sat, Apr 16, 2016 at 12:57 AM, Kevin Lemonnier > > > > > > > ><lemonnierk@xxxxxxxxx> > > > > > > > >wrote: > > > > > > > > > > > > > > > >> Hi, > > > > > > > >> > > > > > > > >> We have a small glusterFS 3.7.6 cluster with 3 nodes running > > > with > > > > > > > >proxmox > > > > > > > >> VM's on it. I did set up the different recommended option like > > > the > > > > > > > >virt > > > > > > > >> group, but > > > > > > > >> by hand since it's on debian. The shards are 256MB, if that > > > matters. > > > > > > > >> > > > > > > > >> This morning the second node crashed, and as it came back up > > > started > > > > > > > >a > > > > > > > >> heal, but that basically froze all the VM's running on that > > > volume. > > > > > > > >Since > > > > > > > >> we really really > > > > > > > >> can't have 40 minutes down time in the middle of the day, I just > > > > > > > >removed > > > > > > > >> the node from the network and that stopped the heal, allowing > > > the > > > > > > > >VM's to > > > > > > > >> access > > > > > > > >> their disks again. The plan was to re-connecte the node in a > > > couple > > > > > > > >of > > > > > > > >> hours to let it heal at night. > > > > > > > >> But a VM crashed now, and it can't boot up again : seems to > > > freez > > > > > > > >trying > > > > > > > >> to access the disks. > > > > > > > >> > > > > > > > >> Looking at the heal info for the volume, it has gone way up > > > since > > > > > > > >this > > > > > > > >> morning, it looks like the VM's aren't writing to both nodes, > > > just > > > > > > > >the one > > > > > > > >> they are on. > > > > > > > >> It seems pretty bad, we have 2 nodes on 3 up, I would expect the > > > > > > > >volume to > > > > > > > >> work just fine since it has quorum. What am I missing ? > > > > > > > >> > > > > > > > >> It is still too early to start the heal, is there a way to > > > start the > > > > > > > >VM > > > > > > > >> anyway right now ? I mean, it was running a moment ago so the > > > data > > > > > is > > > > > > > >> there, it just needs > > > > > > > >> to let the VM access it. > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> Volume Name: vm-storage > > > > > > > >> Type: Replicate > > > > > > > >> Volume ID: a5b19324-f032-4136-aaac-5e9a4c88aaef > > > > > > > >> Status: Started > > > > > > > >> Number of Bricks: 1 x 3 = 3 > > > > > > > >> Transport-type: tcp > > > > > > > >> Bricks: > > > > > > > >> Brick1: first_node:/mnt/vg1-storage > > > > > > > >> Brick2: second_node:/mnt/vg1-storage > > > > > > > >> Brick3: third_node:/mnt/vg1-storage > > > > > > > >> Options Reconfigured: > > > > > > > >> cluster.quorum-type: auto > > > > > > > >> cluster.server-quorum-type: server > > > > > > > >> network.remote-dio: enable > > > > > > > >> cluster.eager-lock: enable > > > > > > > >> performance.readdir-ahead: on > > > > > > > >> performance.quick-read: off > > > > > > > >> performance.read-ahead: off > > > > > > > >> performance.io-cache: off > > > > > > > >> performance.stat-prefetch: off > > > > > > > >> features.shard: on > > > > > > > >> features.shard-block-size: 256MB > > > > > > > >> cluster.server-quorum-ratio: 51% > > > > > > > >> > > > > > > > >> > > > > > > > >> Thanks for your help > > > > > > > >> > > > > > > > >> -- > > > > > > > >> Kevin Lemonnier > > > > > > > >> PGP Fingerprint : 89A5 2283 04A0 E6E9 0111 > > > > > > > >> > > > > > > > >> _______________________________________________ > > > > > > > >> Gluster-users mailing list > > > > > > > >> Gluster-users@xxxxxxxxxxx > > > > > > > >> http://www.gluster.org/mailman/listinfo/gluster-users > > > > > > > >> > > > > > > > > > > > > > > -- > > > > > > > Envoyé de mon appareil Android avec K-9 Mail. Veuillez excuser ma > > > > > brièveté. > > > > > > > _______________________________________________ > > > > > > > Gluster-users mailing list > > > > > > > Gluster-users@xxxxxxxxxxx > > > > > > > http://www.gluster.org/mailman/listinfo/gluster-users > > > > > > > > > > > > > > > > > -- > > > > > Kevin Lemonnier > > > > > PGP Fingerprint : 89A5 2283 04A0 E6E9 0111 > > > > > > > > > > _______________________________________________ > > > > > Gluster-users mailing list > > > > > Gluster-users@xxxxxxxxxxx > > > > > http://www.gluster.org/mailman/listinfo/gluster-users > > > > > > > > > > > -- > > > Kevin Lemonnier > > > PGP Fingerprint : 89A5 2283 04A0 E6E9 0111 > > > > > > _______________________________________________ > > > Gluster-users mailing list > > > Gluster-users@xxxxxxxxxxx > > > http://www.gluster.org/mailman/listinfo/gluster-users > > > > > -- > Kevin Lemonnier > PGP Fingerprint : 89A5 2283 04A0 E6E9 0111 > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://www.gluster.org/mailman/listinfo/gluster-users -- Kevin Lemonnier PGP Fingerprint : 89A5 2283 04A0 E6E9 0111
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