[Nagiosplug-devel] Patch for completeness on check_nt plugin

[Ton Voon]

Paulo, Garry,

This has now been applied to CVS. I wouldn't worry about the 
technicalities of which is the "correct" value - this is what the 
discussion list is for!

Paulo, Thanks for the patch. I've committed it almost verbatim. I've 
only made a slight change to the comments (we are trying to avoid using 
// and use /* */ instead - see the development guidelines at 
http://nagiosplug.sourceforge.net/developer-guidelines.html). I've also 
removed your copyright line from the CHECK_COUNTER code (the developer 
guidelines has a section on the reasons). If you are uncomfortable with 
this, then I can reverse the change.

Ton

On 20 Aug 2004, at 13:28, Paulo Afonso Graner Fessel wrote:

> I've looked at code of check_nt.c and there's this remark:
>  
> // Changed divisor in following line from v to 3044515 to accurately 
> reflect memory size
>  
> This is incorrect. The memory size that check_nt reports is a sum of 
> RAM and pagefile sizes, as defined here:
>  
> "Commit Charge:  In the Windows operating system, the name for the 
> amount of physical memory (RAM) and virtual memory that is allocated 
> to all running programs, or applications, and the operating system 
> itself.
>  
> "Windows Task Manager displays the commit charge in its Performance 
> tab. There are three memory readings, measured in kilobytes:
>  
> * Total: refers to the total amount of physical and virtual memory the 
> computer is using at that moment.
> * Limit: refers to the combined limit of both the physical memory and 
> the allocated virtual memory.
> * Peak: refers to the highest total system memory usage during the 
> session in which you are using the computer.
>  
> "The commit charge will increase when applications are opened and used 
> and decrease when applications are closed."
>  
> So, dividing the memory collected by 3044515 is confusing, to say the 
> least, as what is shown by MEMUSE is actually the Commit 
> Charge. Dividing it by 3044515 assumes that we're using paging space 
> that is two times the size of Physical RAM - this was exactly the 
> reasoning used by a friend of mine, a Windows specialist. But he 
> corrected himself quickly and went to check the paging file size. It 
> was 1.5x the size of physical RAM and could grow up to 2x physical 
> RAM, when neccessary.  But even this behavior may be changed by the 
> user - specifying a paging space that it's 3x the physical RAM, for 
> exemple - thus making the plugin output useless.
>  
> Another problem with this change is that the values returned by the 
> plugin are different that those shown on field "Commit Charge" on 
> Windows Task Manager, and this may confuse Windows SA's.
>  
> Also, the original patch made by Gary Cook seems not to have 
> implemented warning and critical levels for performance counters. I 
> have an alternative implementation that does it, along with some 
> sanity checking of the parameters needed to use -v COUNTER.
>   
> The patch I'm sending solve both issues: it restores the divisor to 1 
> MB and implements warning and critical levels for performance 
> counters. Please evaluate.
>  
> []'s
> Paulo
>  
> Paulo Afonso Graner Fessel
> Administrador de Ambiente e Sistemas UNIX
> paulo.fessel at primesys.com.br
> OWT
> Fone: +55 (11) 3038-6464
> Fax: +55 (11) 3038-6508
> http://www.primesys.com.br
>  
> <image.tiff> 
>  
> <LogoPrimesys.gif><check_nt.perfdata.newpatch>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: text/enriched
Size: 5096 bytes
Desc: not available
URL: <http://nagios-plugins.org/archive/devel/attachments/20040823/0fdf941f/attachment.bin>