----- Original Message ----- > From: "Diego Remolina" <dijuremo@xxxxxxxxx> > To: "Alex Crow" <acrow@xxxxxxxxxxxxxxxx> > Cc: gluster-users@xxxxxxxxxxx > Sent: Monday, September 14, 2015 9:26:17 AM > Subject: Re: Very slow roaming profiles on top of glusterfs > > Hi Alex, > > Thanks for the reply, I was aware of the performance issues with small > files, but never expected an order of magnitude slower. I understand > some improvements were made to 3.7.x to help with low small file > performance, however I did not see any big changes after upgrading > from 3.6.x to 3.7.x. > > http://www.gluster.org/community/documentation/index.php/Features/Feature_Smallfile_Perf > > And the ssd metadata support feature seems to have not had any changes > since September 2014: > > https://forge.gluster.org/gluster-meta-data-on-ssd > > Am I just totally out of luck with gluster for now? Are you using glusterFS mounts or SMB mounts? As for SMB mounts we are working VERY hard to improve metadata / smallfile performance but as it sits right now we are limited by the number of lookup / stat calls that are issued. When we can reduce the number of lookups and prefetch the xattrs that SMB / windows needs(I am working on the stat prefetch but don't have a testable solution yet) I expect to see a vast perf improvement but I don't have an ETA for you. On the glusterFS side I see ~300% improvement in smallfile create performance between 3.6 and 3.7. Try setting: gluster volume set testvol server.event-threads 4 gluster volume set testvol client.event-threads 4 gluster volume set testvol cluster.lookup-optimize on Unfortunately WRT to metadata operations a fix went in that has negatively affected performance: https://bugzilla.redhat.com/show_bug.cgi?id=1250241 I used to see about 25k metatdata operations per second, now I am only seeking 6k. It looks like there is a patch but I don't know if the fix will get us back to the 25k OPs per second, maybe Pranith can comment on expectations for: https://bugzilla.redhat.com/show_bug.cgi?id=1250803 To summarize: SMB - no ETA for improvement GlusterFS smallfile create - 300% increase in my env between 3.6 and 3.7 GlusterFS metadata - BZ is in POST(patch is submitted) but I am not sure on the ETA of the fix and if the fix will get back to what I was seeing in 3.6 Hope this helps. -b > > Diego > > On Mon, Sep 14, 2015 at 8:37 AM, Alex Crow <acrow@xxxxxxxxxxxxxxxx> wrote: > > Hi Diego, > > > > I think it's the overhead of fstat() calls. Gluster keeps its metadata on > > the bricks themselves, and this has to be looked up for every file access. > > For big files this is not an issue as it only happens once, but when > > accessing lots of small files this overhead rapidly builds up, the smaller > > the file the worse the issue. Profiles do have hundreds of very small > > files! > > > > I was looking to use GlusterFS for generic file sharing as well, but I > > noticed the same issue while testing backups from a GlusterFS volume. On > > one > > vol (scanned 4-bit greyscale images and small PDFs) backups were taking > > over > > 16 hours whereas with a traditional FS they were completing in just over 1 > > hour. > > > > It may be worth trying out one of the distributed filesystems that use a > > separate in-memory metadata server. I've tried LizardFS and MooseFS and > > they > > are both much faster than GlusterFS for small files, although large-file > > sequential performance is not as good (but still plenty for a Samba > > server). > > > > Alex > > > > > > On 14/09/15 13:21, Diego Remolina wrote: > >> > >> Bump... > >> > >> Anybody has any clues as to how I can try and identify the cause of > >> the slowness? > >> > >> Diego > >> > >> On Wed, Sep 9, 2015 at 7:42 PM, Diego Remolina <dijuremo@xxxxxxxxx> wrote: > >>> > >>> Hi, > >>> > >>> I am running two glusterfs servers as replicas. I have a 3rd server > >>> which provides quorum. Since gluster was introduced, we have had an > >>> issue where windows roaming profiles are extremely slow. The initial > >>> setup was done on 3.6.x and since 3.7.x has small file performance > >>> improvements, I upgraded to 3.7.3, but that has not helped. > >>> > >>> It seems that for some reason gluster is very slow when dealing with > >>> lots of small files. I am not sure how to really troubleshoot this via > >>> samba, but I have come up with other tests that produce rather > >>> disconcerting results as shown below. > >>> > >>> If I run directly on the brick: > >>> [root@ysmha01 /]# time ( find > >>> /bricks/hdds/brick/home/jgibbs/.winprofile.V2 -type f > /dev/null ) > >>> real 0m3.683s > >>> user 0m0.042s > >>> sys 0m0.154s > >>> > >>> Now running on the gluster volume mounted via fuse: > >>> [root@ysmha01 /]# mount | grep export > >>> 10.0.1.6:/export on /export type fuse.glusterfs > >>> (rw,relatime,user_id=0,group_id=0,allow_other,max_read=131072) > >>> > >>> [root@ysmha01 /]# time ( find /export/home/jgibbs/.winprofile.V2 -type > >>> f > /dev/null ) > >>> real 0m57.812s > >>> user 0m0.118s > >>> sys 0m0.374s > >>> > >>> In general, the time to run the command on this particular user can be > >>> up to 2 minutes. If I run the command on the brick first, then it > >>> seems the time to run on the mounted gluster volume is lower like in > >>> the example above. I assume some caching in preserved. > >>> > >>> This particular user has 13,216 files in his roaming profile, which > >>> adds up to about 452MB of data. > >>> > >>> The server performance over samba for copying big files (both read and > >>> write) is great, I can almost max out the gigabit connections on the > >>> desktops. > >>> > >>> Reading from samba share on the server and writing to local drive: > >>> 111MB/s (Copying a 650MB iso file) > >>> Reading from local drive and writing to server samba share: 94MB/s > >>> (Copying a 3.2GB ISO file) > >>> > >>> The servers are connected to the network with 10Gbit adapters and also > >>> use separate adapters; one 10 Gbit adapter is used for services, and > >>> other for the backend storage communication. > >>> > >>> The servers have hardware raid controllers and the samba shares are on > >>> top of an Areca ARC-1882 controller, with a volume made out of 12 2TB > >>> drives in raid 6. > >>> > >>> If you can provide any steps to better troubleshoot this problem and > >>> fix the issue, I will really appreciate it. > >>> > >>> Diego > >>> > >>> Further details about the machines below: > >>> > >>> [root@ysmha01 /]# cat /etc/redhat-release > >>> CentOS Linux release 7.1.1503 (Core) > >>> > >>> [root@ysmha01 /]# gluster volume info export > >>> Volume Name: export > >>> Type: Replicate > >>> Volume ID: b4353b3f-6ef6-4813-819a-8e85e5a95cff > >>> Status: Started > >>> Number of Bricks: 1 x 2 = 2 > >>> Transport-type: tcp > >>> Bricks: > >>> Brick1: 10.0.1.7:/bricks/hdds/brick > >>> Brick2: 10.0.1.6:/bricks/hdds/brick > >>> Options Reconfigured: > >>> performance.io-cache: on > >>> performance.io-thread-count: 64 > >>> nfs.disable: on > >>> cluster.server-quorum-type: server > >>> performance.cache-size: 1024MB > >>> server.allow-insecure: on > >>> cluster.server-quorum-ratio: 51% > >>> > >>> Each server has dual Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz with > >>> 32GB of memory. > >> > >> _______________________________________________ > >> Gluster-users mailing list > >> Gluster-users@xxxxxxxxxxx > >> http://www.gluster.org/mailman/listinfo/gluster-users > > > > > > -- > > This message is intended only for the addressee and may contain > > confidential information. 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