[Gluster-users] Monitoring and solving split-brain
Ravishankar N
ravishankar at redhat.com
Thu Oct 15 01:38:48 UTC 2015
On 10/14/2015 11:08 PM, Игорь Бирюлин wrote:
> Thanks for detailed description.
> Do you have a plans add resolution GFID split-brain by 'gluster volume
> heal VOLNAME split-brain ...' ?
Not at the moment..
> What the main different between GFID split-brain and data split brain?
> On nodes this file absolutely different by data content and size or it
> isn't 'data' in glusterfs meaning?
>
GFID is unique to a file (something akin to an inode number) and is
assigned when a file is created. Data split-brain occurs when the file
with same gfid already exists on both bricks, but there's a difference
in the file's content. (eg. one write succeeded only on brick1 and
another write only on brick2).
gfid split-brain occurs when a file creation happens twice (say an
application does an open() with O_CREAT) but succeeds only on one brick
each time.
> Best regards,
> Igor
>
>
>
> 2015-10-14 20:13 GMT+03:00 Ravishankar N <ravishankar at redhat.com
> <mailto:ravishankar at redhat.com>>:
>
>
>
> On 10/14/2015 10:05 PM, Игорь Бирюлин wrote:
>> Thanks for your replay.
>>
>> If I do listing in mount point (/repo):
>> # ls /repo/xxx/keyrings/debian-keyring.gpg
>> ls: cannot access /repo/xxx/keyrings/debian-keyring.gpg:
>> Input/output error
>> #
>> In log /var/log/glusterfs/repo.log I see:
>> [2015-10-14 16:27:36.006815] W [MSGID: 108008]
>> [afr-self-heal-name.c:359:afr_selfheal_name_gfid_mismatch_check]
>> 0-repofiles-replicate-0: GFID mismatch for
>> <gfid:4a99bf9d-7423-47d9-a09d-fabaa333eccf>/debian-keyring.gpg
>> 69aaeee6-624b-400a-aa46-b5c6166c014c on repofiles-client-1 and
>> b95ad06e-786a-44e5-ba71-af661982071f on repofiles-client-0
>
> So the file has ended up in GFID split-brain (The trusted.gfid
> value is different in both bricks as seen in your output below.),
> which cannot be handled by the split-brain resolution commands.
> These commands can only resolve data and metadata split-brain. I'm
> afraid you'll manually need to delete one of the file and the
> .glusterfs hardlink from the brick. Not sure why the
> parent-directory was not listed in 'gluster v heal VOLNAME info
> split-brain' output.
>
>> [2015-10-14 16:27:36.008996] W [fuse-bridge.c:451:fuse_entry_cbk]
>> 0-glusterfs-fuse: 65961: LOOKUP()
>> /xxx/keyrings/debian-keyring.gpg => -1 (Input/output error)
>>
>> On first node getfattr return:
>> # getfattr -d -m . -e hex
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> getfattr: Removing leading '/' from absolute path names
>> # file:
>> storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> trusted.afr.dirty=0x000000000000000000000000
>> trusted.afr.repofiles-client-1=0x000000020000000100000000
>> trusted.bit-rot.version=0x020000000000000055fdf0910003b37b
>> trusted.gfid=0xb95ad06e786a44e5ba71af661982071f
>> # ls -l
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> -rw-r--r-- 2 root root 3456271 Oct 13 19:00
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> #
>>
>> On second node getfattr return:
>> # getfattr -d -m . -e hex
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> getfattr: Removing leading '/' from absolute path names
>> # file:
>> storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> trusted.afr.dirty=0x000000000000000000000000
>> trusted.afr.repofiles-client-0=0x000000000000000000000000
>> trusted.bit-rot.version=0x020000000000000055f97b57000dc3c6
>> trusted.gfid=0x69aaeee6624b400aaa46b5c6166c014c
>> # ls -l
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> -rw-r--r-- 2 root root 3450346 Oct 9 16:22
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg
>> #
>>
>> Best regards,
>> Igor
>>
>>
>>
>>
>>
>>
>> 2015-10-14 19:14 GMT+03:00 Ravishankar N <ravishankar at redhat.com
>> <mailto:ravishankar at redhat.com>>:
>>
>>
>>
>> On 10/14/2015 07:02 PM, Игорь Бирюлин wrote:
>>> Hello,
>>> today in my 2 nodes replica set I've found split-brain.
>>> Command 'ls' start told 'Input/output error'.
>>
>> What does the mount log
>> (/var/log/glusterfs/<path-to-mount>.log) say when you get
>> this error?
>>
>> Can you run getfattr as root for the file from *both* bricks
>> and share the result?
>> `getfattr -d -m . -e hex
>> /storage/gluster_brick_repofiles/xxx/keyrings/debian-keyring.gpg`
>>
>> Thanks.
>> Ravi
>>
>>
>>> But command 'gluster v heal VOLNAME info split-brain' does
>>> not show problem files:
>>> # gluster v heal repofiles info split-brain
>>> Brick dist-int-master03.xxx:/storage/gluster_brick_repofiles
>>> Number of entries in split-brain: 0
>>>
>>> Brick dist-int-master04.xxx:/storage/gluster_brick_repofiles
>>> Number of entries in split-brain: 0
>>> #
>>> In output of 'gluster v heal VOLNAME info' I see problem
>>> files (/xxx/keyrings/debian-keyring.gpg, /repos.json), but
>>> without split-brain markers:
>>> # gluster v heal repofiles info
>>> Brick dist-int-master03.xxx:/storage/gluster_brick_repofiles
>>> /xxx/keyrings/debian-keyring.gpg
>>> <gfid:09ec49c9-911a-4b83-abe8-080fe79e7c69>
>>> <gfid:35c51b11-a7fb-496d-9e88-6d5a54fda7da>
>>> /repos.json
>>> <gfid:4f5cb2b5-30e2-43b0-a935-cfc42af883bf>
>>> <gfid:9d2fc354-37c0-47a7-b9f3-379504cba797>
>>> <gfid:cd86a246-9fc4-47d2-bb4d-67566677f77a>
>>> <gfid:b932eed0-07e9-45c5-943e-7478e9f654b4>
>>> <gfid:28bf2ffe-948c-4c7d-bce6-966242338581>
>>> <gfid:ee5659ae-1335-42c5-a852-790387b4213b>
>>> <gfid:fdfb6b8c-3c04-435a-b8d3-8d8341b66409>
>>> Number of entries: 11
>>>
>>> Brick dist-int-master04.xxx:/storage/gluster_brick_repofiles
>>> Number of entries: 0
>>> #
>>>
>>> I couldn't solve split-brain by new standard command:
>>> # gluster v heal repofiles split-brain bigger-file /repos.json
>>> Lookup failed on /repos.json:Input/output error
>>> Volume heal failed.
>>> #
>>>
>>> Additional info:
>>> # gluster v info
>>> Volume Name: repofiles
>>> Type: Replicate
>>> Volume ID: 4b0e2a74-f1ca-4fe7-8518-23919e1b5fa0
>>> Status: Started
>>> Number of Bricks: 1 x 2 = 2
>>> Transport-type: tcp
>>> Bricks:
>>> Brick1: dist-int-master03.xxx:/storage/gluster_brick_repofiles
>>> Brick2: dist-int-master04.xxx:/storage/gluster_brick_repofiles
>>> Options Reconfigured:
>>> performance.readdir-ahead: on
>>> client.event-threads: 4
>>> server.event-threads: 4
>>> cluster.lookup-optimize: on
>>> # cat /etc/issue
>>> Ubuntu 14.04.3 LTS \n \l
>>> # dpkg -l | grep glusterfs
>>> ii glusterfs-client 3.7.5-ubuntu1~trusty1 amd64
>>> clustered file-system (client package)
>>> ii glusterfs-common 3.7.5-ubuntu1~trusty1 amd64
>>> GlusterFS common libraries and translator modules
>>> ii glusterfs-server 3.7.5-ubuntu1~trusty1 amd64
>>> clustered file-system (server package)
>>> #
>>>
>>> I have 2 questions:
>>> 1. Why 'gluster v heal VOLNAME info split-brain' doesn't
>>> show actual split-brain? Why in 'gluster v heal VOLNAME
>>> info' I doesn't see markers like 'possible in split-brain'?
>>> How I can monitor my gluster installation if these commands
>>> doesn't show problems?
>>> 2. Why 'gluster volume heal VOLNAME split-brain bigger-file
>>> FILE' doesn't solve split-brain? I understand that I can
>>> solve split-brain remove files from brick but I thought to
>>> use this killer feature.
>>>
>>> Best regards,
>>> Igor
>>>
>>>
>>> _______________________________________________
>>> Gluster-users mailing list
>>> Gluster-users at gluster.org <mailto:Gluster-users at gluster.org>
>>> http://www.gluster.org/mailman/listinfo/gluster-users
>>
>>
>
>
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