Good place to start: do the bricks have to be clients as well? In other words if I copy a file to a Gluster brick without going through a glusterfs or NFS mount will that disrupt the parallel file system? I assumed files need to be routed through a glusterfs mount point for Gluster to be able to track them(?) What's recommended for bricks which also need i/o to the entire volume? Thanks, Mike C. On Feb 14, 2013, at 10:28 AM, harry mangalam <harry.mangalam at uci.edu> wrote: > While I don't understand your 'each brick system also being a client' setup - > you mean that each gluster brick is a native gluster client as well? And that > is where much of your gluster access is coming from? That seems .. suboptimal > if that's the setup. Is there a reason for that setup? > > We have a distributed-only glusterfs feeding a medium cluster over a similar > same setup QDR IPoIB with 4 servers with 2 bricks each. On a fairly busy > system (~80MB/s background), I can get about 100-300MB/s writes to the gluster > fs on a large 1.7GB file. (With tiny writes, the perf decreases > dramatically). > > Here is my config: (if anyone spies something that I should change to increase > my perf, please feel free to point out my mistake) > > gluster: > Volume Name: gl > Type: Distribute > Volume ID: 21f480f7-fc5a-4fd8-a084-3964634a9332 > Status: Started > Number of Bricks: 8 > Transport-type: tcp,rdma > Bricks: > Brick1: bs2:/raid1 > Brick2: bs2:/raid2 > Brick3: bs3:/raid1 > Brick4: bs3:/raid2 > Brick5: bs4:/raid1 > Brick6: bs4:/raid2 > Brick7: bs1:/raid1 > Brick8: bs1:/raid2 > Options Reconfigured: > performance.write-behind-window-size: 1024MB > performance.flush-behind: on > performance.cache-size: 268435456 > nfs.disable: on > performance.io-cache: on > performance.quick-read: on > performance.io-thread-count: 64 > auth.allow: 10.2.*.*,10.1.*.* > > my RAID6s (via 3ware 9750s) are mounted with the following options > > /dev/sdc /raid1 xfs rw,noatime,sunit=512,swidth=8192,allocsize=32m 0 0 > /dev/sdd /raid2 xfs rw,noatime,sunit=512,swidth=7680,allocsize=32m 0 0 > (and should probably be using 'nobarrier,inode64' as well. - testing this now) > > There are some good refs on prepping XFS fs for max perf here: > <http://www.mythtv.org/wiki/Optimizing_Performance#XFS-Specific_Tips> > The script at: > <http://www.mythtv.org/wiki/Optimizing_Performance#Further_Information> > can help to setup the sunit/swidth options. > <http://www.mysqlperformanceblog.com/2011/12/16/setting-up-xfs-the-simple- > edition/> > Your ib interfaces should be using large mtus (65536) > > hjm > > On Wednesday, February 13, 2013 10:35:12 PM Michael Colonno wrote: >> More data: I got the Infiniband network (QDR) working well and >> switched my gluster volume to the Infiniband fabric (IPoIB, not RDMA since >> it doesn't seem to be supported yet for 3.x). The filesystem was slightly >> faster but still well short of what I would expect by a wide margin. Via an >> informal test (timing the movement of a large file) I'm getting several MB/s >> - well short of even a standard Gb network copy. With the faster network >> the CPU load on the brick systems increased dramatically: now I'm seeing >> 200%-250% usage by glusterfsd and glusterfs. >> >> This leads me to believe that gluster is really not enjoying my >> eight-brick, 2x replication volume with each brick system also being a >> client. I tried a rebalance but no measurable effect. Any suggestions for >> improving the performance? Having each brick be a client of itself seemed >> the most logical choice to remove interdependencies but now I'm doubting the >> setup. >> >> >> >> Thanks, >> >> ~Mike C. >> >> >> >> From: gluster-users-bounces at gluster.org >> [mailto:gluster-users-bounces at gluster.org] On Behalf Of Joe Julian >> Sent: Sunday, February 03, 2013 11:47 AM >> To: gluster-users at gluster.org >> Subject: Re: high CPU load on all bricks >> >> >> >> On 02/03/2013 11:22 AM, Michael Colonno wrote: >> >> >> >> Having taken a lot more data it does seem the glusterfsd and >> glusterd processes (along with several ksoftirqd) spike up to near 100% on >> both client and brick servers during any file transport across the mount. >> Thankfully this is short-lived for the most part but I'm wondering if this >> is expected behavior or what others have experienced(?) I'm a little >> surprised such a large CPU load would be required to move small files and / >> or use an application within a Gluster mount point. >> >> >> If you're getting ksoftirqd spikes, that sounds like a hardware issue to me. >> I never see huge spikes like that on my servers nor clients. >> >> >> >> >> >> >> I wanted to test this against an NFS mount of the same Gluster >> volume. I managed to get rstatd installed and running but my attempts to >> mount the volume via NFS are met with: >> >> >> >> mount.nfs: requested NFS version or transport protocol is not >> supported >> >> >> >> Relevant line in /etc/fstab: >> >> >> >> node1:/volume /volume nfs >> defaults,_netdev,vers=3,mountproto=tcp 0 0 >> >> >> >> It looks like CentOS 6.x has NFS version 4 built into everything. So a few >> questions: >> >> >> >> - Has anyone else noted significant performance differences between a >> glusterfs mount and NFS mount for volumes of 8+ bricks? >> >> - Is there a straightforward way to make the newer versions of CentOS >> play nice with NFS version 3 + Gluster? >> >> - Are there any general performance tuning guidelines I can follow to >> improve CPU performance? I found a few references to the cache settings but >> nothing solid. >> >> >> >> If the consensus is that NFS will not gain anything then I won't waste the >> time setting it all up. >> >> >> NFS gains you the use of FSCache to cache directories and file stats making >> directory listings faster, but it adds overhead decreasing the overall >> throughput (from all the reports I've seen). >> >> I would suspect that you have the kernel nfs server running on your servers. >> Make sure it's disabled. >> >> >> >> >> >> >> Thanks, >> >> ~Mike C. >> >> >> >> >> >> From: gluster-users-bounces at gluster.org >> [mailto:gluster-users-bounces at gluster.org] On Behalf Of Michael Colonno >> Sent: Friday, February 01, 2013 4:46 PM >> To: gluster-users at gluster.org >> Subject: Re: high CPU load on all bricks >> >> >> >> Update: after a few hours the CPU usage seems to have dropped >> down to a small value. I did not change anything with respect to the >> configuration or unmount / stop anything as I wanted to see if this would >> persist for a long period of time. Both the client and the self-mounted >> bricks are now showing CPU < 1% (as reported by top). Prior to the larger >> CPU loads I installed a bunch of software into the volume (~ 5 GB total). Is >> this kind a transient behavior - by which I mean larger CPU loads after a >> lot of filesystem activity in short time - typical? This is not a problem >> in my deployment; I just want to know what to expect in the future and to >> complete this thread for future users. If this is expected behavior we can >> wrap up this thread. If not then I'll do more digging into the logs on the >> client and brick sides. >> >> >> >> Thanks, >> >> ~Mike C. >> >> >> >> From: Joe Julian [mailto:joe at julianfamily.org] >> Sent: Friday, February 01, 2013 2:08 PM >> To: Michael Colonno; gluster-users at gluster.org >> Subject: Re: high CPU load on all bricks >> >> >> >> Check the client log(s). >> >> Michael Colonno <mcolonno at stanford.edu> wrote: >> >> Forgot to mention: on a client system (not a brick) the >> glusterfs process is consuming ~ 68% CPU continuously. This is a much less >> powerful desktop system so the CPU load can't be compared 1:1 with the >> systems comprising the bricks but still very high. So the issue seems to >> exist with both glusterfsd and glusterfs processes. >> >> >> >> Thanks, >> >> ~Mike C. >> >> >> >> From: gluster-users-bounces at gluster.org >> [mailto:gluster-users-bounces at gluster.org] On Behalf Of Michael Colonno >> Sent: Friday, February 01, 2013 12:46 PM >> To: gluster-users at gluster.org >> Subject: high CPU load on all bricks >> >> >> >> Gluster gurus ~ >> >> >> >> I've deployed and 8-brick (2x replicate) Gluster 3.3.1 volume on >> CentOS 6.3 with tcp transport. I was able to build, start, mount, and use >> the volume. On each system contributing a brick, however, my CPU usage >> (glusterfsd) is hovering around 20% (virtually zero memory usage >> thankfully). These are brand new, fairly beefy servers so 20% CPU load is >> quite a bit. The deployment is pretty plain with each brick mounting the >> volume to itself via a glusterfs mount. I assume this type of CPU usage is >> atypically high; is there anything I can do to investigate what's soaking up >> CPU and minimize it? Total usable volume size is only about 22 TB (about 45 >> TB total with 2x replicate). >> >> >> >> Thanks, >> >> ~Mike C. >> >> >> >> >> _____ >> >> >> Gluster-users mailing list >> Gluster-users at gluster.org >> http://supercolony.gluster.org/mailman/listinfo/gluster-users >> >> >> >> >> >> >> _______________________________________________ >> Gluster-users mailing list >> Gluster-users at gluster.org >> http://supercolony.gluster.org/mailman/listinfo/gluster-users > > --- > Harry Mangalam - Research Computing, OIT, Rm 225 MSTB, UC Irvine > [m/c 2225] / 92697 Google Voice Multiplexer: (949) 478-4487 > 415 South Circle View Dr, Irvine, CA, 92697 [shipping] > MSTB Lat/Long: (33.642025,-117.844414) (paste into Google Maps) > --- > "Something must be done. [X] is something. Therefore, we must do it." > Bruce Schneier, on American response to just about anything.
