[Sheepdog] [PATCH v2 1/3] sheep: introduce SD_STATUS_HALT

[Liu Yuan]

On 10/14/2011 05:38 PM, MORITA Kazutaka wrote:
>
>> Good idea. I am totally fond of this feature, it makes sheepdog more
>> symmetrically attractive. IIUC, we need to implement 'sub sheepdog
>> cluster' concept.
>>
>> zone                 0                     1
>>                           +                     +
>>                            |                      |
>> subzone     ------------         -----------
>>                      |     |     |          |     |     |
>>                     +    +   +        +    +   +
>>                     0'   1'    2'        '0    '1   '2
>>
>> I can not simply guess how hard it is to implement. I'll look at this
>> concept after Kazum refactor the membership code, probably after 0.3.0
>> release.
>> Kazum, any comment for this idea?
> I don't yet fully understand the idea.  When we want to have 2 copies
> in zone 0 and 1 copy in zone1, how to specify it with subzone?
>
>
> Thanks,
>
> Kazutaka

Grr, why my drawing get distorted by thunderbird.

how about bellow steps? suppose we only support 2 levels.

three nodes, n0,n1 for zone 0, n2 for zone 1.

top zone                     +
                                     |
                   ----------------------------
                   +                              +
subzone     0                              1
                    |                               |
             ---------------                     -
  node   #             #                    #
             0              1                    2
============================
set it globally:

n0: sheep store -z 0 -sz 0
n1: sheep store -z 0 -sz 1
n2: sheep store -z 1 -sz 0

one of 3 nodes: collie cluster format --zone_copies 2 --subzone_copies 
0,2 --subzone_copies 1,1

============================
or set it at zone level:

n0: sheep store -z 0 -sz 0
n1: sheep store -z 0 -sz 1
n2: sheep store -z 1 -sz 0

one of n0, n1: collie cluster format --copies 2
n2: collie cluster format --copies 1

after all the sub-zones get formated, the top level cluster 
automatically  begins to work.

Thanks,
Yuan