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

[Liu Yuan]

On 10/14/2011 06:06 PM, Liu Yuan wrote:

> 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


Okay, resend it for distorted drawing.
---

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