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Hadoop >> mail # user >> Re: How are 'PHYSICAL_MEMORY_BYTES' and 'VIRTUAL_MEMORY_BYTES' calculated?


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Re: How are 'PHYSICAL_MEMORY_BYTES' and 'VIRTUAL_MEMORY_BYTES' calculated?

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 <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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,
>
>