[Gluster-users] Extremely slow Gluster performance
Patrick Rennie
patrickmrennie at gmail.com
Wed Apr 24 07:27:54 UTC 2019
Hi Nithya,
Thanks for your reply. I believe this issue first began a few weeks ago,
and has been intermittent and gradually gotten worse. I've seen it take as
long as 20 minutes to do a simple ls on our gluster mount via FUSE.
My colleague upgraded us from 3.12 to 3.13 about 2 days ago as he thought
it might help but it didn't change much. Immediately following the upgrade,
the performance was good, but within 10-15 minutes it had gotten much worse
again.
We have one brick process which has been killed right now, and performance
has gone from 5-20 mins to do an "ls" down to about 20-60 seconds, we are
hoping that this will allow some other bricks to heal and then once those
issues are resolved, we will restart this brick process again. We
determined which brick to try and kill by monitoring the load of our disks
and finding out which disk was struggling the most. Within seconds of
killing the brick process, performance significantly improved, then
gradually got a little bit worse again. Our current theory is that there
are too many heal operations going on, and our CPU/disks are struggling a
bit with all of the load from heals, plus hundreds of clients accessing and
trying to write new data. This is probably not the best way to go about it,
but we have had to do this to keep things usable for our clients. Our
workload consists of 24/7 backup data being written to this cluster.
I am also in the process of trying to delete several million files from a
directory we no longer need to reduce some small file i/o from the cluster.
I believe there are still a lot of files which do need to be healed, I ran
a "gluster volume <vol> heal info summary" which I can do now in 3.13 and
there are a handful of files on some bricks which need healing, and several
thousand on one brick, I will include a copy of that too.
I have done as you suggested and collected 2 sample tcp dumps for you. If
it's OK with you, I will email this to you separately as it may contain
sensitive production data.
Thank you for your assistance, much appreciated.
Kind Regards,
- Patrick
On Wed, Apr 24, 2019 at 12:04 PM Nithya Balachandran <nbalacha at redhat.com>
wrote:
> Hi Patrick,
>
> Did this start only after the upgrade?
> How do you determine which brick process to kill?
> Are there a lot of files to be healed on the volume?
>
> Can you provide a tcpdump of the slow listing from a separate test client
> mount ?
>
> 1. Mount the gluster volume on a different mount point than the one
> being used by your users.
> 2. Start capturing packets on the system where you have mounted the
> volume in (1).
> - tcpdump -i any -s 0 -w /var/tmp/dirls.pcap tcp and not port 22
> 3. List the directory that is slow from the fuse client
> 4. Stop the capture (after a couple of minutes or after the listing
> returns, whichever is earlier)
> 5. Send us the pcap and the listing of the same directory from one of
> the bricks in order to compare the entries.
>
>
> We may need more information post looking at the tcpdump.
>
> Regards,
> Nithya
>
> On Tue, 23 Apr 2019 at 23:39, 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
>>
>>
>> _______________________________________________
>> Gluster-users mailing list
>> Gluster-users at gluster.org
>> https://lists.gluster.org/mailman/listinfo/gluster-users
>
>
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