[Gluster-users] Rebuild Distributed/Replicated Setup
Pranith Kumar. Karampuri
pranithk at gluster.com
Thu May 19 08:44:52 UTC 2011
hi Remi,
This is a classic case of split-brain. See if the md5sum of the files in question matches on both web01, web02. If yes you can safely reset the xattr of the file on one of the replicas to trigger self-heal. If the md5sums dont match, you will have to select the machine you want to keep as the source (In your case it is web01), go to the other machine (In your case it is web02) and execute the following commands:
1) sudo setxattr -n trusted.afr.shared-application-data-client-0 -v 0sAAAAAAAAAAAAAAAA <file-name>.
2) then do a find on the <file-name>,
that will trigger self-heal and both copies will be in replication again.
Self-heal can cause a performance hit if you trigger self-heal for all the files at once if they are BIG files. so trigger 1 after the other upon completion in that case.
Let me know if you need any more help with this. Removing the whole web02 data and triggering a total self-heal is very expensive operation, I wouldn't do that.
Pranith.
----- Original Message -----
From: "Remi Broemeling" <remi at goclio.com>
To: "Pranith Kumar. Karampuri" <pranithk at gluster.com>
Cc: gluster-users at gluster.org
Sent: Wednesday, May 18, 2011 8:21:33 PM
Subject: Re: [Gluster-users] Rebuild Distributed/Replicated Setup
Sure,
These files are just a sampling -- a lot of other files are showing the same "split-brain" behaviour.
[14:42:45][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223185/contact.log
# file: agc/production/log/809223185/contact.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAABQAAAAAAAAAA
[14:45:15][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223185/contact.log
# file: agc/production/log/809223185/contact.log
trusted.afr.shared-application-data-client-0=0sAAACOwAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
[14:42:53][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223185/event.log
# file: agc/production/log/809223185/event.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAADgAAAAAAAAAA
[14:45:24][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223185/event.log
# file: agc/production/log/809223185/event.log
trusted.afr.shared-application-data-client-0=0sAAAGXQAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
[14:43:02][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223635/contact.log
# file: agc/production/log/809223635/contact.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAACgAAAAAAAAAA
[14:45:28][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809223635/contact.log
# file: agc/production/log/809223635/contact.log
trusted.afr.shared-application-data-client-0=0sAAAELQAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
[14:43:39][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809224061/contact.log
# file: agc/production/log/809224061/contact.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAACQAAAAAAAAAA
[14:45:32][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809224061/contact.log
# file: agc/production/log/809224061/contact.log
trusted.afr.shared-application-data-client-0=0sAAAD+AAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
[14:43:42][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809224321/contact.log
# file: agc/production/log/809224321/contact.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAACAAAAAAAAAAA
[14:45:37][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809224321/contact.log
# file: agc/production/log/809224321/contact.log
trusted.afr.shared-application-data-client-0=0sAAAERAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
[14:43:45][root at web01:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809215319/event.log
# file: agc/production/log/809215319/event.log
trusted.afr.shared-application-data-client-0=0sAAAAAAAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAABwAAAAAAAAAA
[14:45:45][root at web02:/var/glusterfs/bricks/shared]# getfattr -d -m "trusted.afr*" agc/production/log/809215319/event.log
# file: agc/production/log/809215319/event.log
trusted.afr.shared-application-data-client-0=0sAAAC/QAAAAAAAAAA
trusted.afr.shared-application-data-client-1=0sAAAAAAAAAAAAAAAA
On Wed, May 18, 2011 at 01:31, Pranith Kumar. Karampuri < pranithk at gluster.com > wrote:
hi Remi,
It seems the split-brain is detected on following files:
/agc/production/log/809223185/contact.log
/agc/production/log/809223185/event.log
/agc/production/log/809223635/contact.log
/agc/production/log/809224061/contact.log
/agc/production/log/809224321/contact.log
/agc/production/log/809215319/event.log
Could you give the output of the following command for each file above on both the bricks in the replica pair.
getxattr -d -m "trusted.afr*" <filepath>
Thanks
Pranith
----- Original Message -----
From: "Remi Broemeling" < remi at goclio.com >
To: gluster-users at gluster.org
Sent: Tuesday, May 17, 2011 9:02:44 PM
Subject: Re: [Gluster-users] Rebuild Distributed/Replicated Setup
Hi Pranith. Sure, here is a pastebin sampling of logs from one of the hosts: http://pastebin.com/1U1ziwjC
On Mon, May 16, 2011 at 20:48, Pranith Kumar. Karampuri < pranithk at gluster.com > wrote:
hi Remi,
Would it be possible to post the logs on the client, so that we can find what issue you are running into.
Pranith
----- Original Message -----
From: "Remi Broemeling" < remi at goclio.com >
To: gluster-users at gluster.org
Sent: Monday, May 16, 2011 10:47:33 PM
Subject: [Gluster-users] Rebuild Distributed/Replicated Setup
Hi,
I've got a distributed/replicated GlusterFS v3.1.2 (installed via RPM) setup across two servers (web01 and web02) with the following vol config:
volume shared-application-data-client-0
type protocol/client
option remote-host web01
option remote-subvolume /var/glusterfs/bricks/shared
option transport-type tcp
option ping-timeout 5
end-volume
volume shared-application-data-client-1
type protocol/client
option remote-host web02
option remote-subvolume /var/glusterfs/bricks/shared
option transport-type tcp
option ping-timeout 5
end-volume
volume shared-application-data-replicate-0
type cluster/replicate
subvolumes shared-application-data-client-0 shared-application-data-client-1
end-volume
volume shared-application-data-write-behind
type performance/write-behind
subvolumes shared-application-data-replicate-0
end-volume
volume shared-application-data-read-ahead
type performance/read-ahead
subvolumes shared-application-data-write-behind
end-volume
volume shared-application-data-io-cache
type performance/io-cache
subvolumes shared-application-data-read-ahead
end-volume
volume shared-application-data-quick-read
type performance/quick-read
subvolumes shared-application-data-io-cache
end-volume
volume shared-application-data-stat-prefetch
type performance/stat-prefetch
subvolumes shared-application-data-quick-read
end-volume
volume shared-application-data
type debug/io-stats
subvolumes shared-application-data-stat-prefetch
end-volume
In total, four servers mount this via GlusterFS FUSE. For whatever reason (I'm really not sure why), the GlusterFS filesystem has run into a bit of split-brain nightmare (although to my knowledge an actual split brain situation has never occurred in this environment), and I have been getting solidly corrupted issues across the filesystem as well as complaints that the filesystem cannot be self-healed.
What I would like to do is completely empty one of the two servers (here I am trying to empty server web01), making the other one (in this case web02) the authoritative source for the data; and then have web01 completely rebuild it's mirror directly from web02.
What's the easiest/safest way to do this? Is there a command that I can run that will force web01 to re-initialize it's mirror directly from web02 (and thus completely eradicate all of the split-brain errors and data inconsistencies)?
Thanks!
--
Remi Broemeling
System Administrator
Clio - Practice Management Simplified
1-888-858-2546 x(2^5) | remi at goclio.com
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