Re: Gluster FUSE mount sometimes reports that files do not exist until ls is performed on parent directory

[Nithya Balachandran <nbalacha@xxxxxxxxxx>]

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@xxxxxxxxxx> wrote:

On 16 April 2018 at 14:07, Raghavendra Gowdappa <rgowdapp@xxxxxxxxxx> wrote:

On Mon, Apr 16, 2018 at 1:54 PM, Niels Hendriks <niels@xxxxxxxxxx> 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@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users

_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users

_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users