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HDFS >> mail # user >> Re: System.out.printlin vs Counters


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zheyi rong 2013-03-27, 10:38
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Paul Wilkinson 2013-03-27, 11:20
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Re: System.out.printlin vs Counters
I do not understand 1 and 2: Counters are used to count things in the MR
framework in a distributed manner and get aggregate at the JobTracker
level; System.out is merely used to write to STDOUT. Why are you
comparing the two?

3: The limit means the total number of counter names accepted from a
single job. Your example would create one such new counter called
TestGroup1.TestName1. You could also increment TestName2, etc.… but
only up to a global max of 120 of such new counters.

On Wed, Mar 27, 2013 at 3:51 PM, Sai Sai <[EMAIL PROTECTED]> wrote:
> Q1. Is it right to assume the System.out.println statements are used only in
> eclipse environment and
> In a multi node cluster environment we need to use counters.
>
> Q2. I am slightly confused as it appears like using System.out.println
> statements
> we r able to get detailed info at every line of code in eclipse and counters
> just give few lines and not as detailed as System.out.println statements do
> so what should we do in a multi node cluster enivronment.
>
> Q3. Also when they say the limit of counters is 120 does that mean that in
> the output if we use:
> context.getCounters("TestGroup1","TestName1").increment(1);
> more than 120 times it will not print it. or does it refer to 120 options of
> counters in an enum that we can define.
>
> Any help is really appreciated.
> Thanks
> Sai
>
>

--
Harsh J