[Gluster-users] Gluster FUSE mount sometimes reports that files do not exist until ls is performed on parent directory

[Nithya Balachandran]

Hi Niels,

As this is a pure replicate volume, lookup-optimize is not going to be much
use so you can turn it off if you wish.

Do you see any error messages in the FUSE mount logs when this happens?
If it happens again, a tcpdump of the fuse mount would help.


Regards,
Nithya

On 16 April 2018 at 14:59, Nithya Balachandran <nbalacha at redhat.com> wrote:

>
>
> On 16 April 2018 at 14:07, Raghavendra Gowdappa <rgowdapp at redhat.com>
> wrote:
>
>>
>>
>> On Mon, Apr 16, 2018 at 1:54 PM, Niels Hendriks <niels at nuvini.com> wrote:
>>
>>> Hi,
>>>
>>> We have a 3-node gluster setup where gluster is both the server and the
>>> client.
>>> Every few days we have some $random file or directory that does not exist
>>> according to the FUSE mountpoint. When we try to access the file (stat,
>>> cat, etc...) the filesystem reports that the file/directory does not
>>> exist,
>>> even though it does. When we try to create the file/directory we receive
>>> the following error which is also logged in
>>> /var/log/glusterfs/bricks/$brick.log:
>>>
>>> [2018-04-10 12:51:26.755928] E [MSGID: 113027] [posix.c:1779:posix_mkdir]
>>> 0-www-posix: mkdir of /storage/gluster/path/to/dir failed [File exists]
>>>
>>> We don't see this issue on all of the servers, but only on the servers
>>> that
>>> did not create the file/directory (so 2 of the 3 gluster nodes).
>>>
>>> We found that this issue does not resolve itself automatically. However,
>>> when we perform an ls command on the parent directory the issue will be
>>> resolved for the other nodes.
>>>
>>> We are running glusterfs 3.12.6 on debian 8
>>>
>>> Mount-options in /etc/fstab:
>>> /dev/storage-gluster/gluster /storage/gluster xfs
>>> rw,inode64,noatime,nouuid
>>> 0 2
>>> localhost:/www /var/www glusterfs
>>> backup-volfile-servers=10.0.0.2:10.0.0.3,log-level=WARNING
>>> 0 0
>>>
>>> gluster volume info www
>>>
>>> Volume Name: www
>>> Type: Replicate
>>> Volume ID: e0579d53-f671-4868-863b-ba85c4cfacb3
>>> Status: Started
>>> Snapshot Count: 0
>>> Number of Bricks: 1 x 3 = 3
>>> Transport-type: tcp
>>> Bricks:
>>> Brick1: n01c01-gluster:/storage/gluster/www
>>> Brick2: n02c01-gluster:/storage/gluster/www
>>> Brick3: n03c01-gluster:/storage/gluster/www
>>> Options Reconfigured:
>>> performance.read-ahead: on
>>> performance.client-io-threads: on
>>> nfs.disable: on
>>> transport.address-family: inet
>>> performance.md-cache-timeout: 600
>>> diagnostics.brick-log-level: WARNING
>>> network.ping-timeout: 3
>>> features.cache-invalidation: on
>>> server.event-threads: 4
>>> performance.cache-invalidation: on
>>> performance.quick-read: on
>>> features.cache-invalidation-timeout: 600
>>> network.inode-lru-limit: 90000
>>> performance.cache-priority: *.php:3,*.temp:3,*:1
>>> performance.nl-cache: on
>>> performance.cache-size: 1GB
>>> performance.readdir-ahead: on
>>> performance.write-behind: on
>>> cluster.readdir-optimize: on
>>> performance.io-thread-count: 64
>>> client.event-threads: 4
>>> cluster.lookup-optimize: on
>>> performance.parallel-readdir: off
>>> performance.write-behind-window-size: 4MB
>>> performance.flush-behind: on
>>> features.bitrot: on
>>> features.scrub: Active
>>> performance.io-cache: off
>>> performance.stat-prefetch: on
>>>
>>> We suspected that the md-cache could be the cause, but it does have a
>>> timeout of 600 seconds so this would be strange since the issue can be
>>> present for hours (at which point we did an ls to fix it).
>>>
>>> Does anyone have an idea of what could be the cause of this?
>>>
>>
>> For files, it could be because of:
>> * cluster.lookup-optimize set to on
>> * datafile is present on non hashed subvol, but linkto file is absent on
>> hashed subvol
>>
>>
> This is a pure replicate volume:
>
> Type: Replicate
> Volume ID: e0579d53-f671-4868-863b-ba85c4cfacb3
> Status: Started
> Snapshot Count: 0
> Number of Bricks: 1 x 3 = 3
>
>
>
> So unlikely to be a lookup-optimize problem.
>
>
>
>> I see that lookup-optimize is on. Can you get the following information
>> from problematic file?
>>
>> * Name of the file
>> * all xattrs on parent directory from all bricks
>> * stat of file from all bricks where it is present.
>> * all xattrs on file from all bricks where it is present.
>>
>> If you are seeing the problem on directory,
>> * Name of directory
>> * xattr of directory and its parent from all bricks
>>
>> regards,
>> Raghavendra
>>
>>
>>> Thanks!
>>>
>>>
>>> _______________________________________________
>>> Gluster-users mailing list
>>> Gluster-users at gluster.org
>>> http://lists.gluster.org/mailman/listinfo/gluster-users
>>>
>>
>>
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>
>
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