> On June 10, 2014, 9:22 a.m., Ben Mahler wrote:
> > Please do a grep for 'quorum', I believe there are a few other places that 
> > need to be modified (mesos-local and tests).
> > 
> > What if both flags are specified? We should either reject this or validate 
> > the values (e.g. quorum=1 masters=3 is not safe, quorum=4 masters=3 is 
> > invalid).

I see, there is another bug in auto initialization code, which get clusterSize 
as quorum * 2 - 1, this is not correct, say below examples.

num-masters quorum clusterSize
1           1      1
2           2      3 (wrong)
3           2      3
4           3      5 (wrong)
5           3      5
...

So need more changes to code. I'd like to describe my idea before submit a new 
version of patch.

1. since 0.19.0 is freezing, this patch will go 0.20.x

There are two options I'd like to hear from you.

1. --num_masters will replace --quorum, means overwrite --quorum for several 
releases and finally remove '--quorum', so no non-standard quorum will be used. 
quorum = num_master / 2 + 1
2. both --num_masters and --quorum are used, user can specify non-standard 
quorum if he like, specify a larger quorum may introduce performance regression 
while a smaller quorum may introduce inconsistency.

Generally, I vote the first option, how do you think?


> On June 10, 2014, 9:22 a.m., Ben Mahler wrote:
> > src/master/flags.hpp, line 69
> > <https://reviews.apache.org/r/22369/diff/2/?file=606291#file606291line69>
> >
> >     'num_masters' here and elsewhere


- Chengwei


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On June 10, 2014, 9:03 a.m., Chengwei Yang wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/22369/
> -----------------------------------------------------------
> 
> (Updated June 10, 2014, 9:03 a.m.)
> 
> 
> Review request for mesos.
> 
> 
> Bugs: https://issues.apache.org/jira/browse/MESOS-1465
>     
> https://issues.apache.org/jira/browse/https://issues.apache.org/jira/browse/MESOS-1465
> 
> 
> Repository: mesos-git
> 
> 
> Description
> -------
> 
> Use '--nr_of_masters' instead of '--quorum' because user may confused
> with zookeeper quorum and may specify an incorrect quorum if he/she
> doesn't know quorum well.
> 
> Use '--nr_of_masters' just simple and straight-forward, and quorum will
> be nr_of_masters / 2 + 1, since specify a larger quorum doesn't make
> sense in pratice.
> 
> Review: https://reviews.apache.org/r/22369
> 
> 
> Diffs
> -----
> 
>   src/master/flags.hpp 4863359 
>   src/master/main.cpp 8ceaae6 
> 
> Diff: https://reviews.apache.org/r/22369/diff/
> 
> 
> Testing
> -------
> 
> done.
> 
> 
> Thanks,
> 
> Chengwei Yang
> 
>

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