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From Harsh J <ha...@cloudera.com>
Subject Re: are we able to decommission multi nodes at one time?
Date Tue, 02 Apr 2013 07:54:50 GMT
Note though that its only possible to decommission 7 nodes at the same
time and expect it to finish iff the remaining 8 nodes have adequate
free space for the excess replicas.

If you're just going to take them down for a short while (few mins
each), its easier to do so in a rolling manner without need of a
decommission. You can take upto two down at a time on a replication
average of 3 or 3+, and put it back in later without too much data
movement impact.

On Tue, Apr 2, 2013 at 1:06 PM, Yanbo Liang <yanbohappy@gmail.com> wrote:
> It's reasonable to decommission 7 nodes at the same time.
> But may be it also takes long time to finish it.
> Because all the replicas in these 7 nodes need to be copied to remaining 8
> nodes.
> The size of transfer from these nodes to the remaining nodes is equal.
>
>
> 2013/4/2 Henry Junyoung Kim <henry.jykim@gmail.com>
>>
>> :)
>>
>> currently, I  have 15 data nodes.
>> for some tests, I am trying to decommission until 8 nodes.
>>
>> Now, the total dfs used size is 52 TB which is including all replicated
>> blocks.
>> from 15 to 8, total spent time is almost 4 days long. ;(
>>
>> someone mentioned that I don't need to decommission node by node.
>> for this case, is there no problems if I decommissioned 7 nodes at the
>> same time?
>>
>>
>> 2013. 4. 2., 오후 12:14, Azuryy Yu <azuryyyu@gmail.com> 작성:
>>
>> I can translate it to native English: how many nodes you want to
>> decommission?
>>
>>
>> On Tue, Apr 2, 2013 at 11:01 AM, Yanbo Liang <yanbohappy@gmail.com> wrote:
>>>
>>> You want to decommission how many nodes?
>>>
>>>
>>> 2013/4/2 Henry JunYoung KIM <henry.jykim@gmail.com>
>>>>
>>>> 15 for datanodes and 3 for replication factor.
>>>>
>>>> 2013. 4. 1., 오후 3:23, varun kumar <varun.uid@gmail.com> 작성:
>>>>
>>>> > How many nodes do you have and replication factor for it.
>>>>
>>>
>>
>>
>



-- 
Harsh J

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