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From sandeep das <yarnhad...@gmail.com>
Subject Re: Max Parallel task executors
Date Fri, 06 Nov 2015 12:51:21 GMT
HI Laxman,

Thanks for your response. I had already configured a very high value
for yarn.nodemanager.resource.cpu-vcores
e.g. 40 but still its not increasing more number of parallel tasks to
execute but if this value is reduced then it runs less number of parallel
tasks.

As of now yarn.nodemanager.resource.memory-mb is configured to 16 GB
and yarn.nodemanager.resource.cpu-vcores
configured to 40.

Still its not spawning more tasks than 31.

Let me know if more information is required to debug it. I believe there is
upper limit after which yarn stops spawning tasks. I may be wrong here.


Regards,
Sandeep

On Fri, Nov 6, 2015 at 6:15 PM, Laxman Ch <laxman.lux@gmail.com> wrote:

> Hi Sandeep,
>
> Please configure the following items to the cores and memory per node you
> wanted to allocate for Yarn containers.
> Their defaults are 8 cores and 8GB. So that's the reason you were stuck at
> 31 (4nodes * 8cores - 1 AppMaster)
>
>
> http://hadoop.apache.org/docs/r2.6.0/hadoop-yarn/hadoop-yarn-common/yarn-default.xml
> yarn.nodemanager.resource.cpu-vcores
> yarn.nodemanager.resource.memory-mb
>
>
> On 6 November 2015 at 17:59, sandeep das <yarnhadoop@gmail.com> wrote:
>
>> May be to naive to ask but How do I check that?
>> Sometimes there are almost 200 map tasks pending to run but at a time
>> only 31 runs.
>>
>> On Fri, Nov 6, 2015 at 5:57 PM, Chris Mawata <chris.mawata@gmail.com>
>> wrote:
>>
>>> Also check that you have more than 31 blocks to process.
>>> On Nov 6, 2015 6:54 AM, "sandeep das" <yarnhadoop@gmail.com> wrote:
>>>
>>>> Hi Varun,
>>>>
>>>> I tried to increase this parameter but it did not increase number of
>>>> parallel tasks but if It is decreased then YARN reduces number of parallel
>>>> tasks. I'm bit puzzled why its not increasing more than 31 tasks even after
>>>> its value is increased.
>>>>
>>>> Is there any other configuration as well which controls on how many
>>>> maximum tasks can execute in parallel?
>>>>
>>>> Regards,
>>>> Sandeep
>>>>
>>>> On Tue, Nov 3, 2015 at 7:29 PM, Varun Vasudev <vvasudev@apache.org>
>>>> wrote:
>>>>
>>>>> The number of parallel tasks that are run depends on the amount of
>>>>> memory and vcores on your machines and the amount of memory and vcores
>>>>> required by your mappers and reducers. The amount of memory can be set
>>>>> via yarn.nodemanager.resource.memory-mb(the default is 8G). The amount
of
>>>>> vcores can be set via yarn.nodemanager.resource.cpu-vcores(the
>>>>> default is 8 vcores).
>>>>>
>>>>> -Varun
>>>>>
>>>>> From: sandeep das <yarnhadoop@gmail.com>
>>>>> Reply-To: <user@hadoop.apache.org>
>>>>> Date: Monday, November 2, 2015 at 3:56 PM
>>>>> To: <user@hadoop.apache.org>
>>>>> Subject: Max Parallel task executors
>>>>>
>>>>> Hi Team,
>>>>>
>>>>> I've a cloudera cluster of 4 nodes. Whenever i submit a job my only 31
>>>>> parallel tasks are executed whereas my machines have more CPU available
but
>>>>> still YARN/AM does not create more task.
>>>>>
>>>>> Is there any configuration which I can change to start more
>>>>> MAP/REDUCER task in parallel?
>>>>>
>>>>> Each machine in my cluster has 24 CPUs.
>>>>>
>>>>> Regards,
>>>>> Sandeep
>>>>>
>>>>
>>>>
>>
>
>
> --
> Thanks,
> Laxman
>

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