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Posted to mapreduce-user@hadoop.apache.org by GUOJUN Zhu <gu...@freddiemac.com> on 2012/07/17 15:13:31 UTC

What exactly does the "CPU time spent (ms)" measure?

Sometimes there are big discrepency between this time and the real running 
time at the task level.  It can be significantly less than the real 
running time; for some case, I observe that it is longer than the real 
running time.  What exactly does this counter measure? Thanks. 

Zhu, Guojun
Modeling Sr Graduate
571-3824370
guojun_zhu@freddiemac.com
Financial Engineering
Freddie Mac

Re: What exactly does the "CPU time spent (ms)" measure?

Posted by GUOJUN Zhu <gu...@freddiemac.com>.
It is "Map-Reduce Framework/CPU time spent (ms)" (the shown name in all 
webpage or console) counter for every run? 

Zhu, Guojun
Modeling Sr Graduate
571-3824370
guojun_zhu@freddiemac.com
Financial Engineering
Freddie Mac



   Arun C Murthy <ac...@hortonworks.com> 
   07/17/2012 01:39 PM
   Please respond to
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Re: What exactly does the "CPU time spent (ms)" measure?






Zhu,

 Do you mean the 'slot millis' counter?

Arun

On Jul 17, 2012, at 6:13 AM, GUOJUN Zhu wrote:


Sometimes there are big discrepency between this time and the real running 
time at the task level.  It can be significantly less than the real 
running time; for some case, I observe that it is longer than the real 
running time.  What exactly does this counter measure? Thanks. 

Zhu, Guojun
Modeling Sr Graduate
571-3824370
guojun_zhu@freddiemac.com
Financial Engineering
Freddie Mac

--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/

Re: What exactly does the "CPU time spent (ms)" measure?

Posted by Arun C Murthy <ac...@hortonworks.com>.
Zhu,

 Do you mean the 'slot millis' counter?

Arun

On Jul 17, 2012, at 6:13 AM, GUOJUN Zhu wrote:

> 
> Sometimes there are big discrepency between this time and the real running time at the task level.  It can be significantly less than the real running time; for some case, I observe that it is longer than the real running time.  What exactly does this counter measure? Thanks. 
> 
> Zhu, Guojun
> Modeling Sr Graduate
> 571-3824370
> guojun_zhu@freddiemac.com
> Financial Engineering
> Freddie Mac

--
Arun C. Murthy
Hortonworks Inc.
http://hortonworks.com/