hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Vinod Kumar Vavilapalli <vino...@hortonworks.com>
Subject Re: How are 'PHYSICAL_MEMORY_BYTES' and 'VIRTUAL_MEMORY_BYTES' calculated?
Date Sat, 13 Jul 2013 00:10:38 GMT

No, every so often, 3 seconds IIRC, it capture pmem and vmem which corresponds to the usage
of the process and its children at *that* specific point of time. Cumulative = cumulative
across the process and its children.

Thanks,
+Vinod

On Jul 12, 2013, at 1:47 PM, hadoop qi wrote:

> Thanks for the response. So they represent the total physical memory (virtual memory)
has been allocated to the job (e.g., from heap and stack) during its entire life time? I am
still confused how to get the cumulative number from /proc/meminfo. I think from /proc/meminfo
we can only get the memory usage of a  process in a particular time point (looked like a snapshot
of the status of the process). If these numbers are added, the sum would be much more than
memory allocated to the program. 
> 
> 
> On Fri, Jul 12, 2013 at 6:47 AM, Shahab Yunus <shahab.yunus@gmail.com> wrote:
> I think they are cumulative but per task.
> 
> Physical memory bytes
> (PHYSICAL_MEMORY_BYTES)
> The physical memory being used by a task in bytes, as reported by /proc/meminfo.
> Virtual memory bytes
> (VIRTUAL_MEMORY_BYTES)
> The virtual memory being used by a task in bytes, as reported by /proc/meminfo.
> 
> This is from the Definitive Guide book. Page 260.
> 
> Regards,
> Shhab
> 
> 
> On Thu, Jul 11, 2013 at 12:47 PM, hadoop qi <hadoop.jqi@gmail.com> wrote:
> Hello, 
> 
> I am wondering how memory counters  'PHYSICAL_MEMORY_BYTES'  and 'VIRTUAL_MEMORY_BYTES'
 are calculated? They are peaks of memory usage or cumulative usage? 
> 
> Thanks for help, 
> 
> 


Mime
View raw message