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

[Strahil Nikolov]

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