Hi Ben, Regarding https://bugzilla.redhat.com/show_bug.cgi?id=1250241which does look like a serious regression for small file performance, do you know which versions are affected, or is there a way to find out?
Also the patch didn't make it: do you have visibility on whether another patch is likely to land soon? If not I may try the version before the regression was introduced... Thanks, Thibault. On 14 Sep 2015 4:22 pm, "Ben Turner" <[email protected]> wrote: > ----- Original Message ----- > > From: "Diego Remolina" <[email protected]> > > To: "Alex Crow" <[email protected]> > > Cc: [email protected] > > Sent: Monday, September 14, 2015 9:26:17 AM > > Subject: Re: [Gluster-users] 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 <[email protected]> > 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 <[email protected]> > 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 > > >> [email protected] > > >> 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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