[Gluster-users] Extremely slow file listing in folders with many files

Thu Apr 30 18:05:19 UTC 2020

I did this on the same prod instance just now.

'find' on a fuse gluster dir with 40k+ files:
1st run: 3m56.261s
2nd run: 0m24.970s
3rd run: 0m24.099s

At this point, I killed all gluster services on one of the 4 servers and
verified that that brick went offline.

1st run: 0m38.131s
2nd run: 0m19.369s
3rd run: 0m23.576s

Nothing conclusive really IMO.

Sincerely,
Artem

--
Founder, Android Police <http://www.androidpolice.com>, APK Mirror
<http://www.apkmirror.com/>, Illogical Robot LLC
beerpla.net | @ArtemR <http://twitter.com/ArtemR>

On Thu, Apr 30, 2020 at 9:55 AM Strahil Nikolov <hunter86_bg at yahoo.com>
wrote:

> On April 30, 2020 6:27:10 PM GMT+03:00, Artem Russakovskii <
> archon810 at gmail.com> wrote:
> >Hi Strahil, in the original email I included both the times for the
> >first
> >and subsequent reads on the fuse mounted gluster volume as well as the
> >xfs
> >filesystem the gluster data resides on (this is the brick, right?).
> >
> >On Thu, Apr 30, 2020, 7:44 AM Strahil Nikolov <hunter86_bg at yahoo.com>
> >wrote:
> >
> >> On April 30, 2020 4:24:23 AM GMT+03:00, Artem Russakovskii <
> >> archon810 at gmail.com> wrote:
> >> >Hi all,
> >> >
> >> >We have 500GB and 10TB 4x1 replicate xfs-based gluster volumes, and
> >the
> >> >10TB one especially is extremely slow to do certain things with (and
> >> >has
> >> >been since gluster 3.x when we started). We're currently on 5.13.
> >> >
> >> >The number of files isn't even what I'd consider that great - under
> >> >100k
> >> >per dir.
> >> >
> >> >Here are some numbers to look at:
> >> >
> >> >On gluster volume in a dir of 45k files:
> >> >The first time
> >> >
> >> >time find | wc -l
> >> >45423
> >> >real    8m44.819s
> >> >user    0m0.459s
> >> >sys     0m0.998s
> >> >
> >> >And again
> >> >
> >> >time find | wc -l
> >> >45423
> >> >real    0m34.677s
> >> >user    0m0.291s
> >> >sys     0m0.754s
> >> >
> >> >
> >> >If I run the same operation on the xfs block device itself:
> >> >The first time
> >> >
> >> >time find | wc -l
> >> >45423
> >> >real    0m13.514s
> >> >user    0m0.144s
> >> >sys     0m0.501s
> >> >
> >> >And again
> >> >
> >> >time find | wc -l
> >> >45423
> >> >real    0m0.197s
> >> >user    0m0.088s
> >> >sys     0m0.106s
> >> >
> >> >
> >> >I'd expect a performance difference here but just as it was several
> >> >years
> >> >ago when we started with gluster, it's still huge, and simple file
> >> >listings
> >> >are incredibly slow.
> >> >
> >> >At the time, the team was looking to do some optimizations, but I'm
> >not
> >> >sure this has happened.
> >> >
> >> >What can we do to try to improve performance?
> >> >
> >> >Thank you.
> >> >
> >> >
> >> >
> >> >Some setup values follow.
> >> >
> >> >xfs_info /mnt/SNIP_block1
> >> >meta-data=/dev/sdc               isize=512    agcount=103,
> >> >agsize=26214400
> >> >blks
> >> >         =                       sectsz=512   attr=2, projid32bit=1
> >> >      =                       crc=1        finobt=1, sparse=0,
> >rmapbt=0
> >> >         =                       reflink=0
> >> >data     =                       bsize=4096   blocks=2684354560,
> >> >imaxpct=25
> >> >         =                       sunit=0      swidth=0 blks
> >> >naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
> >> >log      =internal log           bsize=4096   blocks=51200,
> >version=2
> >> >        =                       sectsz=512   sunit=0 blks,
> >lazy-count=1
> >> >realtime =none                   extsz=4096   blocks=0, rtextents=0
> >> >
> >> >Volume Name: SNIP_data1
> >> >Type: Replicate
> >> >Volume ID: SNIP
> >> >Status: Started
> >> >Snapshot Count: 0
> >> >Number of Bricks: 1 x 4 = 4
> >> >Transport-type: tcp
> >> >Bricks:
> >> >Brick1: nexus2:/mnt/SNIP_block1/SNIP_data1
> >> >Brick2: forge:/mnt/SNIP_block1/SNIP_data1
> >> >Brick3: hive:/mnt/SNIP_block1/SNIP_data1
> >> >Brick4: citadel:/mnt/SNIP_block1/SNIP_data1
> >> >Options Reconfigured:
> >> >cluster.quorum-count: 1
> >> >cluster.quorum-type: fixed
> >> >network.ping-timeout: 5
> >> >network.remote-dio: enable
> >> >performance.rda-cache-limit: 256MB
> >> >performance.readdir-ahead: on
> >> >performance.parallel-readdir: on
> >> >network.inode-lru-limit: 500000
> >> >performance.md-cache-timeout: 600
> >> >performance.cache-invalidation: on
> >> >performance.stat-prefetch: on
> >> >features.cache-invalidation-timeout: 600
> >> >features.cache-invalidation: on
> >> >cluster.readdir-optimize: on
> >> >performance.io-thread-count: 32
> >> >server.event-threads: 4
> >> >client.event-threads: 4
> >> >performance.read-ahead: off
> >> >cluster.lookup-optimize: on
> >> >performance.cache-size: 1GB
> >> >cluster.self-heal-daemon: enable
> >> >transport.address-family: inet
> >> >nfs.disable: on
> >> >performance.client-io-threads: on
> >> >cluster.granular-entry-heal: enable
> >> >cluster.data-self-heal-algorithm: full
> >> >
> >> >Sincerely,
> >> >Artem
> >> >
> >> >--
> >> >Founder, Android Police <http://www.androidpolice.com>, APK Mirror
> >> ><http://www.apkmirror.com/>, Illogical Robot LLC
> >> >beerpla.net | @ArtemR <http://twitter.com/ArtemR>
> >>
> >> Hi Artem,
> >>
> >> Have you checked the same on brick level ? How big is the difference
> >?
> >>
> >> Best Regards,
> >> Strahil Nikolov
> >>
>
> Hi Artem,
>
> My bad I missed the 'xfs' word... Still the difference  is huge.
>
> May I ask you to do a test again (pure curiosity) as follows:
> 1. Repeat the test from before
> 2. Stop 1 brick  and test again.
>
>
> P.S.: You can try it on the test cluster
>
> Best Regards,
> Strahil Nikolov
>
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