Bug 765555 (GLUSTER-3823)

Summary: Add command-line support for enforce-quorum option
Product: [Community] GlusterFS Reporter: Jeff Darcy <jdarcy>
Component: cliAssignee: Amar Tumballi <amarts>
Status: CLOSED CURRENTRELEASE QA Contact:
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Priority: medium    
Version: pre-releaseCC: gluster-bugs, vijay, vraman
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Hardware: x86_64   
OS: Linux   
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Description Jeff Darcy 2011-11-21 17:49:32 UTC
Now that it's a feature in the code, might as well provide an easy way to enable it.  Still NO_DOC, though, since we don't necessarily want people changing it without being briefed on the implications.

Comment 1 Vijay Bellur 2011-11-22 13:44:31 UTC
How about making quorum count configurable too?

Comment 2 Jeff Darcy 2011-11-22 14:10:24 UTC
(In reply to comment #1)
> How about making quorum count configurable too?

What would the options be?  Quorum count (Q) is already determined algorithmically, based on the total replica count (R).  Let's examine the cases.

* Q=1 is equivalent to no quorum enforcement, except that writers get EROFS instead of EIO.  Not sure if this is useful.

* Q=2, R=2 (i.e. no special case for first brick) seems marginally useful.

* Q=2, R=3 is what we already get for any R=3.

* Q=3, R=3 also seems marginally useful.

* R>3 will remain too rare to worry about.

So both of the marginally useful cases require unanimity.  Would it make more sense to have a separate quorum-count option, or allow enforce-quorum (quorum-type) to have more than two values?

* "none" = no enforcement

* "majority" = what's there now

* "all" = require presence of all servers

Comment 3 Anand Avati 2011-11-28 13:46:35 UTC
CHANGE: http://review.gluster.com/743 (Change-Id: Ia52ddb551e24c27969f7f5fa0f94c1044789731f) merged in master by Vijay Bellur (vijay)