If your datanode has 2 HDFS-chunks (blocks) of the input file, the scheduler
will first prefer to run 2 map tasks on the tasktracker where this datanode
resides.
On Fri, Jul 1, 2011 at 10:33 PM, Juwei Shi <shiju...@gmail.com> wrote:
> I think that Anthony is right. Task capacity has to been set at
> mapred-default.html, and restart the cluster.
>
> Anthony Urso
>
>
>
> 2011/7/2 <praveen.pe...@nokia.com>
>
> Are you sure? AFAIK all mapred.xxx properties can be set via job config. I
>> also read on yahoo tutorial that this property can be either set in
>> hadoop-site.XML or job config. May be someone can confirm this who have
>> really used this property.
>>
>> Praveen
>>
>> On Jul 1, 2011, at 4:46 PM, "ext Anthony Urso" <antho...@cs.ucla.edu>
>> wrote:
>>
>> > On Fri, Jul 1, 2011 at 1:03 PM, <praveen.pe...@nokia.com> wrote:
>> >> Hi all,
>> >>
>> >> I am using hadoop 0.20.2. I am setting the property
>> >> mapred.tasktracker.map.tasks.maximum = 4 (same for reduce also) on my
>> job
>> >> conf but I am still seeing max of only 2 map and reduce tasks on each
>> node.
>> >> I know my machine can run 4 maps and 4 reduce tasks in parallel. Is
>> this a
>> >> bug in 0.20.2 or am I doing something wrong?
>> >>
>> >>
>> >
>> > If I remember correctly, you have to set this in your hadoop-site.xml
>> > and restart your job tracker and task trackers.
>> >
>> >>
>> >> Configuration conf = new Configuration();
>> >>
>> >> conf.set("mapred.tasktracker.map.tasks.maximum", "4");
>> >>
>> >> conf.set("mapred.tasktracker.reduce.tasks.maximum", "4");
>> >>
>> >>
>> >>
>> >> Thanks
>> >>
>> >> Praveen
>>
>
>
>
> --
> - Juwei
>
--
Best Regards,
Mostafa Ead
