[Gluster-users] Extremely slow cluster performance
Darrell Budic
budic at onholyground.com
Sat Apr 20 14:50:08 UTC 2019
Patrick,
I would definitely upgrade your two nodes from 3.12.14 to 3.12.15. You also mention ZFS, and that error you show makes me think you need to check to be sure you have “xattr=sa” and “acltype=posixacl” set on your ZFS volumes.
You also observed your bricks are crossing the 95% full line, ZFS performance will degrade significantly the closer you get to full. In my experience, this starts somewhere between 10% and 5% free space remaining, so you’re in that realm.
How’s your free memory on the servers doing? Do you have your zfs arc cache limited to something less than all the RAM? It shares pretty well, but I’ve encountered situations where other things won’t try and take ram back properly if they think it’s in use, so ZFS never gets the opportunity to give it up.
Since your volume is a disperse-replica, you might try tuning disperse.shd-max-threads, default is 1, I’d try it at 2, 4, or even more if the CPUs are beefy enough. And setting server.event-threads to 4 and client.event-threads to 8 has proven helpful in many cases. After you get upgraded to 3.12.15, enabling performance.stat-prefetch may help as well. I don’t know if it matters, but I’d also recommend resetting performance.least-prio-threads to the default of 1 (or try 2 or 4) and/or also setting performance.io <http://performance.io/>-thread-count to 32 if those have beefy CPUs.
Beyond those general ideas, more info about your hardware (CPU and RAM) and workload (VMs, direct storage for web servers or enders, etc) may net you some more ideas. Then you’re going to have to do more digging into brick logs looking for errors and/or warnings to see what’s going on.
-Darrell
> On Apr 20, 2019, at 8:22 AM, Patrick Rennie <patrickmrennie at gmail.com> wrote:
>
> Hello Gluster Users,
>
> I am hoping someone can help me with resolving an ongoing issue I've been having, I'm new to mailing lists so forgive me if I have gotten anything wrong. We have noticed our performance deteriorating over the last few weeks, easily measured by trying to do an ls on one of our top-level folders, and timing it, which usually would take 2-5 seconds, and now takes up to 20 minutes, which obviously renders our cluster basically unusable. This has been intermittent in the past but is now almost constant and I am not sure how to work out the exact cause. We have noticed some errors in the brick logs, and have noticed that if we kill the right brick process, performance instantly returns back to normal, this is not always the same brick, but it indicates to me something in the brick processes or background tasks may be causing extreme latency. Due to this ability to fix it by killing the right brick process off, I think it's a specific file, or folder, or operation which may be hanging and causing the increased latency, but I am not sure how to work it out. One last thing to add is that our bricks are getting quite full (~95% full), we are trying to migrate data off to new storage but that is going slowly, not helped by this issue. I am currently trying to run a full heal as there appear to be many files needing healing, and I have all brick processes running so they have an opportunity to heal, but this means performance is very poor. It currently takes over 15-20 minutes to do an ls of one of our top-level folders, which just contains 60-80 other folders, this should take 2-5 seconds. This is all being checked by FUSE mount locally on the storage node itself, but it is the same for other clients and VMs accessing the cluster. Initially, it seemed our NFS mounts were not affected and operated at normal speed, but testing over the last day has shown that our NFS clients are also extremely slow, so it doesn't seem specific to FUSE as I first thought it might be.
>
> I am not sure how to proceed from here, I am fairly new to gluster having inherited this setup from my predecessor and trying to keep it going. I have included some info below to try and help with diagnosis, please let me know if any further info would be helpful. I would really appreciate any advice on what I could try to work out the cause. Thank you in advance for reading this, and any suggestions you might be able to offer.
>
> - Patrick
>
> This is an example of the main error I see in our brick logs, there have been others, I can post them when I see them again too:
> [2019-04-20 04:54:43.055680] E [MSGID: 113001] [posix.c:4940:posix_getxattr] 0-gvAA01-posix: getxattr failed on /brick1/<filename> library: system.posix_acl_default [Operation not supported]
> [2019-04-20 05:01:29.476313] W [posix.c:4929:posix_getxattr] 0-gvAA01-posix: Extended attributes not supported (try remounting brick with 'user_xattr' flag)
>
> Our setup consists of 2 storage nodes and an arbiter node. I have noticed our nodes are on slightly different versions, I'm not sure if this could be an issue. We have 9 bricks on each node, made up of ZFS RAIDZ2 pools - total capacity is around 560TB.
> We have bonded 10gbps NICS on each node, and I have tested bandwidth with iperf and found that it's what would be expected from this config.
> Individual brick performance seems ok, I've tested several bricks using dd and can write a 10GB files at 1.7GB/s.
>
> # dd if=/dev/zero of=/brick1/test/test.file bs=1M count=10000
> 10000+0 records in
> 10000+0 records out
> 10485760000 bytes (10 GB, 9.8 GiB) copied, 6.20303 s, 1.7 GB/s
>
> Node 1:
> # glusterfs --version
> glusterfs 3.12.15
>
> Node 2:
> # glusterfs --version
> glusterfs 3.12.14
>
> Arbiter:
> # glusterfs --version
> glusterfs 3.12.14
>
> Here is our gluster volume status:
>
> # gluster volume status
> Status of volume: gvAA01
> Gluster process TCP Port RDMA Port Online Pid
> ------------------------------------------------------------------------------
> Brick 01-B:/brick1/gvAA01/brick 49152 0 Y 7219
> Brick 02-B:/brick1/gvAA01/brick 49152 0 Y 21845
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck1 49152 0 Y 6931
> Brick 01-B:/brick2/gvAA01/brick 49153 0 Y 7239
> Brick 02-B:/brick2/gvAA01/brick 49153 0 Y 9916
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck2 49153 0 Y 6939
> Brick 01-B:/brick3/gvAA01/brick 49154 0 Y 7235
> Brick 02-B:/brick3/gvAA01/brick 49154 0 Y 21858
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck3 49154 0 Y 6947
> Brick 01-B:/brick4/gvAA01/brick 49155 0 Y 31840
> Brick 02-B:/brick4/gvAA01/brick 49155 0 Y 9933
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck4 49155 0 Y 6956
> Brick 01-B:/brick5/gvAA01/brick 49156 0 Y 7233
> Brick 02-B:/brick5/gvAA01/brick 49156 0 Y 9942
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck5 49156 0 Y 6964
> Brick 01-B:/brick6/gvAA01/brick 49157 0 Y 7234
> Brick 02-B:/brick6/gvAA01/brick 49157 0 Y 9952
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck6 49157 0 Y 6974
> Brick 01-B:/brick7/gvAA01/brick 49158 0 Y 7248
> Brick 02-B:/brick7/gvAA01/brick 49158 0 Y 9960
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck7 49158 0 Y 6984
> Brick 01-B:/brick8/gvAA01/brick 49159 0 Y 7253
> Brick 02-B:/brick8/gvAA01/brick 49159 0 Y 9970
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck8 49159 0 Y 6993
> Brick 01-B:/brick9/gvAA01/brick 49160 0 Y 7245
> Brick 02-B:/brick9/gvAA01/brick 49160 0 Y 9984
> Brick 00-A:/arbiterAA01/gvAA01/bri
> ck9 49160 0 Y 7001
> NFS Server on localhost 2049 0 Y 17276
> Self-heal Daemon on localhost N/A N/A Y 25245
> NFS Server on 02-B 2049 0 Y 9089
> Self-heal Daemon on 02-B N/A N/A Y 17838
> NFS Server on 00-a 2049 0 Y 15660
> Self-heal Daemon on 00-a N/A N/A Y 16218
>
> Task Status of Volume gvAA01
> ------------------------------------------------------------------------------
> There are no active volume tasks
>
> And gluster volume info:
>
> # gluster volume info
>
> Volume Name: gvAA01
> Type: Distributed-Replicate
> Volume ID: ca4ece2c-13fe-414b-856c-2878196d6118
> Status: Started
> Snapshot Count: 0
> Number of Bricks: 9 x (2 + 1) = 27
> Transport-type: tcp
> Bricks:
> Brick1: 01-B:/brick1/gvAA01/brick
> Brick2: 02-B:/brick1/gvAA01/brick
> Brick3: 00-A:/arbiterAA01/gvAA01/brick1 (arbiter)
> Brick4: 01-B:/brick2/gvAA01/brick
> Brick5: 02-B:/brick2/gvAA01/brick
> Brick6: 00-A:/arbiterAA01/gvAA01/brick2 (arbiter)
> Brick7: 01-B:/brick3/gvAA01/brick
> Brick8: 02-B:/brick3/gvAA01/brick
> Brick9: 00-A:/arbiterAA01/gvAA01/brick3 (arbiter)
> Brick10: 01-B:/brick4/gvAA01/brick
> Brick11: 02-B:/brick4/gvAA01/brick
> Brick12: 00-A:/arbiterAA01/gvAA01/brick4 (arbiter)
> Brick13: 01-B:/brick5/gvAA01/brick
> Brick14: 02-B:/brick5/gvAA01/brick
> Brick15: 00-A:/arbiterAA01/gvAA01/brick5 (arbiter)
> Brick16: 01-B:/brick6/gvAA01/brick
> Brick17: 02-B:/brick6/gvAA01/brick
> Brick18: 00-A:/arbiterAA01/gvAA01/brick6 (arbiter)
> Brick19: 01-B:/brick7/gvAA01/brick
> Brick20: 02-B:/brick7/gvAA01/brick
> Brick21: 00-A:/arbiterAA01/gvAA01/brick7 (arbiter)
> Brick22: 01-B:/brick8/gvAA01/brick
> Brick23: 02-B:/brick8/gvAA01/brick
> Brick24: 00-A:/arbiterAA01/gvAA01/brick8 (arbiter)
> Brick25: 01-B:/brick9/gvAA01/brick
> Brick26: 02-B:/brick9/gvAA01/brick
> Brick27: 00-A:/arbiterAA01/gvAA01/brick9 (arbiter)
> Options Reconfigured:
> cluster.shd-max-threads: 4
> performance.least-prio-threads: 16
> cluster.readdir-optimize: on
> performance.quick-read: off
> performance.stat-prefetch: off
> cluster.data-self-heal: on
> cluster.lookup-unhashed: auto
> cluster.lookup-optimize: on
> cluster.favorite-child-policy: mtime
> server.allow-insecure: on
> transport.address-family: inet
> client.bind-insecure: on
> cluster.entry-self-heal: off
> cluster.metadata-self-heal: off
> performance.md-cache-timeout: 600
> cluster.self-heal-daemon: enable
> performance.readdir-ahead: on
> diagnostics.brick-log-level: INFO
> nfs.disable: off
>
> Thank you for any assistance.
>
> - Patrick
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