[Gluster-users] Stale locks on shards

Tue Jan 23 08:30:40 UTC 2018

On Tue, Jan 23, 2018 at 1:38 PM, Samuli Heinonen <samppah at neutraali.net>
wrote:

> Pranith Kumar Karampuri kirjoitti 23.01.2018 09:34:
>
>> On Mon, Jan 22, 2018 at 12:33 AM, Samuli Heinonen
>> <samppah at neutraali.net> wrote:
>>
>> Hi again,
>>>
>>> here is more information regarding issue described earlier
>>>
>>> It looks like self healing is stuck. According to "heal statistics"
>>> crawl began at Sat Jan 20 12:56:19 2018 and it's still going on
>>> (It's around Sun Jan 21 20:30 when writing this). However
>>> glustershd.log says that last heal was completed at "2018-01-20
>>> 11:00:13.090697" (which is 13:00 UTC+2). Also "heal info" has been
>>> running now for over 16 hours without any information. In statedump
>>> I can see that storage nodes have locks on files and some of those
>>> are blocked. Ie. Here again it says that ovirt8z2 is having active
>>> lock even ovirt8z2 crashed after the lock was granted.:
>>>
>>> [xlator.features.locks.zone2-ssd1-vmstor1-locks.inode]
>>> path=/.shard/3d55f8cc-cda9-489a-b0a3-fd0f43d67876.27
>>> mandatory=0
>>> inodelk-count=3
>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0:self-heal
>>> inodelk.inodelk[0](ACTIVE)=type=WRITE, whence=0, start=0, len=0, pid
>>> = 18446744073709551610, owner=d0c6d857a87f0000,
>>> client=0x7f885845efa0,
>>>
>>> connection-id=sto2z2.xxx-10975-2018/01/20-10:56:14:649541-
>> zone2-ssd1-vmstor1-client-0-0-0,
>>
>>> granted at 2018-01-20 10:59:52
>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0:metadata
>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0
>>> inodelk.inodelk[0](ACTIVE)=type=WRITE, whence=0, start=0, len=0, pid
>>> = 3420, owner=d8b9372c397f0000, client=0x7f8858410be0,
>>>
>>> connection-id=ovirt8z2.xxx.com-5652-2017/12/27-09:49:02:9468
>> 25-zone2-ssd1-vmstor1-client-0-7-0,
>>
>>> granted at 2018-01-20 08:57:23
>>> inodelk.inodelk[1](BLOCKED)=type=WRITE, whence=0, start=0, len=0,
>>> pid = 18446744073709551610, owner=d0c6d857a87f0000,
>>> client=0x7f885845efa0,
>>>
>>> connection-id=sto2z2.xxx-10975-2018/01/20-10:56:14:649541-
>> zone2-ssd1-vmstor1-client-0-0-0,
>>
>>> blocked at 2018-01-20 10:59:52
>>>
>>> I'd also like to add that volume had arbiter brick before crash
>>> happened. We decided to remove it because we thought that it was
>>> causing issues. However now I think that this was unnecessary. After
>>> the crash arbiter logs had lots of messages like this:
>>> [2018-01-20 10:19:36.515717] I [MSGID: 115072]
>>> [server-rpc-fops.c:1640:server_setattr_cbk]
>>> 0-zone2-ssd1-vmstor1-server: 37374187: SETATTR
>>> <gfid:a52055bd-e2e9-42dd-92a3-e96b693bcafe>
>>> (a52055bd-e2e9-42dd-92a3-e96b693bcafe) ==> (Operation not permitted)
>>> [Operation not permitted]
>>>
>>> Is there anyways to force self heal to stop? Any help would be very
>>> much appreciated :)
>>>
>>
>> Exposing .shard to a normal mount is opening a can of worms. You
>> should probably look at mounting the volume with gfid aux-mount where
>> you can access a file with <path-to-mount>/.gfid/<gfid-string>to clear
>> locks on it.
>>
>> Mount command:  mount -t glusterfs -o aux-gfid-mount vm1:test
>> /mnt/testvol
>>
>> A gfid string will have some hyphens like:
>> 11118443-1894-4273-9340-4b212fa1c0e4
>>
>> That said. Next disconnect on the brick where you successfully did the
>> clear-locks will crash the brick. There was a bug in 3.8.x series with
>> clear-locks which was fixed in 3.9.0 with a feature. The self-heal
>> deadlocks that you witnessed also is fixed in 3.10 version of the
>> release.
>>
>
>
> Thank you the answer. Could you please tell more about crash? What will
> actually happen or is there a bug report about it? Just want to make sure
> that we can do everything to secure data on bricks. We will look into
> upgrade but we have to make sure that new version works for us and of
> course get self healing working before doing anything :)
>

Locks xlator/module maintains a list of locks that are granted to a client.
Clear locks had an issue where it forgets to remove the lock from this
list. So the connection list ends up pointing to data that is freed in that
list after a clear lock. When a disconnect happens, all the locks that are
granted to a client need to be unlocked. So the process starts traversing
through this list and when it starts trying to access this freed data it
leads to a crash. I found it while reviewing a feature patch sent by
facebook folks to locks xlator (http://review.gluster.org/14816) for 3.9.0
and they also fixed this bug as well as part of that feature patch.

>
> Br,
> Samuli
>
>
>> 3.8.x is EOLed, so I recommend you to upgrade to a supported version
>> soon.
>>
>> Best regards,
>>> Samuli Heinonen
>>>
>>> Samuli Heinonen
>>>> 20 January 2018 at 21.57
>>>>
>>>> Hi all!
>>>>
>>>> One hypervisor on our virtualization environment crashed and now
>>>> some of the VM images cannot be accessed. After investigation we
>>>> found out that there was lots of images that still had active lock
>>>> on crashed hypervisor. We were able to remove locks from "regular
>>>> files", but it doesn't seem possible to remove locks from shards.
>>>>
>>>> We are running GlusterFS 3.8.15 on all nodes.
>>>>
>>>> Here is part of statedump that shows shard having active lock on
>>>> crashed node:
>>>> [xlator.features.locks.zone2-ssd1-vmstor1-locks.inode]
>>>> path=/.shard/75353c17-d6b8-485d-9baf-fd6c700e39a1.21
>>>> mandatory=0
>>>> inodelk-count=1
>>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0:metadata
>>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0:self-heal
>>>> lock-dump.domain.domain=zone2-ssd1-vmstor1-replicate-0
>>>> inodelk.inodelk[0](ACTIVE)=type=WRITE, whence=0, start=0, len=0,
>>>> pid = 3568, owner=14ce372c397f0000, client=0x7f3198388770,
>>>> connection-id
>>>>
>>>>
>>> ovirt8z2.xxx-5652-2017/12/27-09:49:02:946825-zone2-ssd1-vmst
>> or1-client-1-7-0,
>>
>>> granted at 2018-01-20 08:57:24
>>>>
>>>> If we try to run clear-locks we get following error message:
>>>> # gluster volume clear-locks zone2-ssd1-vmstor1
>>>> /.shard/75353c17-d6b8-485d-9baf-fd6c700e39a1.21 kind all inode
>>>> Volume clear-locks unsuccessful
>>>> clear-locks getxattr command failed. Reason: Operation not
>>>> permitted
>>>>
>>>> Gluster vol info if needed:
>>>> Volume Name: zone2-ssd1-vmstor1
>>>> Type: Replicate
>>>> Volume ID: b6319968-690b-4060-8fff-b212d2295208
>>>> Status: Started
>>>> Snapshot Count: 0
>>>> Number of Bricks: 1 x 2 = 2
>>>> Transport-type: rdma
>>>> Bricks:
>>>> Brick1: sto1z2.xxx:/ssd1/zone2-vmstor1/export
>>>> Brick2: sto2z2.xxx:/ssd1/zone2-vmstor1/export
>>>> Options Reconfigured:
>>>> cluster.shd-wait-qlength: 10000
>>>> cluster.shd-max-threads: 8
>>>> cluster.locking-scheme: granular
>>>> performance.low-prio-threads: 32
>>>> cluster.data-self-heal-algorithm: full
>>>> performance.client-io-threads: off
>>>> storage.linux-aio: off
>>>> performance.readdir-ahead: on
>>>> client.event-threads: 16
>>>> server.event-threads: 16
>>>> performance.strict-write-ordering: off
>>>> performance.quick-read: off
>>>> performance.read-ahead: on
>>>> performance.io-cache: off
>>>> performance.stat-prefetch: off
>>>> cluster.eager-lock: enable
>>>> network.remote-dio: on
>>>> cluster.quorum-type: none
>>>> network.ping-timeout: 22
>>>> performance.write-behind: off
>>>> nfs.disable: on
>>>> features.shard: on
>>>> features.shard-block-size: 512MB
>>>> storage.owner-uid: 36
>>>> storage.owner-gid: 36
>>>> performance.io-thread-count: 64
>>>> performance.cache-size: 2048MB
>>>> performance.write-behind-window-size: 256MB
>>>> server.allow-insecure: on
>>>> cluster.ensure-durability: off
>>>> config.transport: rdma
>>>> server.outstanding-rpc-limit: 512
>>>> diagnostics.brick-log-level: INFO
>>>>
>>>> Any recommendations how to advance from here?
>>>>
>>>> Best regards,
>>>> Samuli Heinonen
>>>>
>>>> _______________________________________________
>>>> Gluster-users mailing list
>>>> Gluster-users at gluster.org
>>>> http://lists.gluster.org/mailman/listinfo/gluster-users [1]
>>>>
>>>
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>>>
>>
>> --
>>
>> Pranith
>>
>>
>> Links:
>> ------
>> [1] http://lists.gluster.org/mailman/listinfo/gluster-users
>>
>

-- 
Pranith
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