Re: Conflict resolution

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi David,

You can obtain the values via 'gluster volume get' command. See 'gluster volume get help'.The defaults are also defined and can be seen via 'gluster volume set help'. I think that the quorum ratio in replica 3 is '51'.

With cluster.server-quorum-type set to 'server', the TSP nodes are creating a 'quorum'  and when node3 is disconnected from the majority (quorum), the brick of node3 will shutdown till quorum is restored.

For point 3 , you need to check cluster.quorum-type. If it's set in auto mode , only the  first brick will allow writes (I think we are talking about replica 2 here) . Yet, if you configered the volume that it allows both bricks to be operational (cluster.quorum-type = fixed, cluster.quorum-count =1, volume is replica 2), then:
A) yes
B) no, it should just heal
C) no, it should just heal

The conflict protection from arbiter is the same (we both use extended file attributes on arbiter and full data brick). If a file was not properly updated on node2, both bricks (node1+ node3 ) will 'blame' node2 and thus the heal daemon (if enabled) will try to heal that file.


Best Regards,
Strahil Nikolov

On Wed, Oct 20, 2021 at 3:52, David Cunningham
<dcunningham@xxxxxxxxxxxxx> wrote:
Hello,

I've a few questions about conflict resolution in a net-split scenario:

1. What are the default values for cluster.server-quorum-type and cluster.server-quorum-ratio? (at the moment "gluster volume info gvol0" does not report either)

2. If there are 3 mirrored nodes and cluster.server-quorum-ratio is 50, and node1 and node2 are net-split from node3, then am I right in thinking that the volume on node3 will automatically shut down and prevent access thus preventing a conflict?

3. If there are 2 mirrored nodes and a net-split happens and cluster.server-quorum-ratio is 50 then:
a) If existing file A is changed on node1 and node2 then the file will enter net-split state, right?
b) If existing file B is changed on node1 but not node2 then will the file enter a net-split state?
c) If new file C is written on node1 but not node2 then will the file enter a net-split state?

4. Is the outcome of conflict resolution at a file level the same whether node3 is a full replica or just an arbiter?

Thank you very much for any advice,

--
David Cunningham, Voisonics Limited
http://voisonics.com/
USA: +1 213 221 1092
New Zealand: +64 (0)28 2558 3782
________



Community Meeting Calendar:

Schedule -
Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC
Bridge: https://meet.google.com/cpu-eiue-hvk
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
https://lists.gluster.org/mailman/listinfo/gluster-users
________



Community Meeting Calendar:

Schedule -
Every 2nd and 4th Tuesday at 14:30 IST / 09:00 UTC
Bridge: https://meet.google.com/cpu-eiue-hvk
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
https://lists.gluster.org/mailman/listinfo/gluster-users

[Index of Archives]     [Gluster Development]     [Linux Filesytems Development]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux