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From Varun Saxena <vsaxena.va...@gmail.com>
Subject Re: yarn.nodemanager.resource.cpu-vcores vs yarn.scheduler.maximum-allocation-vcores
Date Sun, 23 Aug 2015 17:20:45 GMT
Hi Pedro,

Real default value of yarn.scheduler.maximum-allocation-vcores is 4.
The value of 32 is actually a documentation issue and has been fixed
recently.

Regards,
Varun Saxena.


On Sun, Aug 23, 2015 at 10:39 PM, Pedro Magalhaes <pedrorjbr@gmail.com>
wrote:

> Varun,
> Thanks for the reply. I undestand the arn.scheduler.maximum-
> allocation-vcores parameter. I just asking why the default parameter is
> yarn.scheduler.maximum-allocation-vcores=32. And
> yarn.nodemanager.resource.cpu-vcores=8.
>
> In my opinion, if the yarn.scheduler.maximun-allocation-vcore is 32 tby
> default the yarn.nodemanager.resource.cpu-vcores  would be equal or greater
> than 32, by default.
> Is this make sense?
>
>
>
>
> On Sun, Aug 23, 2015 at 2:00 PM, Varun Saxena <vsaxena.varun@gmail.com>
> wrote:
>
>> Hi Pedro,
>>
>> Actual allocation would depend on the total resource capability
>> advertised by NM while registering with RM.
>>
>> yarn.scheduler.maximum-allocation-vcores merely puts an upper cap on number of vcores
which can be allocated by RM i.e. any Resource request/ask from AM which asks for vcores >
32(default value) for a container, will be normalized back to 32.
>>
>> If there is no such node available, this allocation will not be fulfilled.
>>
>> yarn.scheduler.maximum-allocation-vcores will be configured in resource
>> manager and hence will be common for a cluster which can possibly have
>> multiple nodes with heterogeneous resource capabilities
>>
>> yarn.nodemanager.resource.cpu-vcores on the other hand will have to be
>> configured as per resource capability of that particular node.
>>
>> Recently there has been work done to automatically get memory and CPU
>> information from underlying OS(supported OS being Linux and Windows) if
>> configured to do so. This change would be available in 2.8
>> I hope this answers your question.
>>
>> Regards,
>> Varun Saxena.
>>
>> On Sun, Aug 23, 2015 at 9:40 PM, Pedro Magalhaes <pedrorjbr@gmail.com>
>> wrote:
>>
>>> I was looking at default parameters for:
>>>
>>> yarn.nodemanager.resource.cpu-vcores = 8
>>> yarn.scheduler.maximum-allocation-vcores = 32
>>>
>>> For me this two parameters as default doesnt make any sense.
>>>
>>> The first one say "the number of CPU cores that can be allocated for
>>> containers." (I imagine that is vcore) The seconds says: "The maximum
>>> allocation for every container request at the RM". In my opinion, the
>>> second one must be equal or less than the first one.
>>>
>>> How can allocate 32 vcores for a container if i have only 8 cores
>>> available per container?
>>>
>>
>>
>

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