Re: Dstat plugin for OpenVZ CPU statistics [message #7507 is a reply to message #7503] |
Mon, 16 October 2006 15:27 ![Go to previous message Go to previous message](/theme/ovz3/images/up.png) ![Go to next message Go to previous message](/theme/ovz3/images/down.png) |
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Dag Wieers wrote:
> On Mon, 16 Oct 2006, Kir Kolyshkin wrote:
>
>
>> Dag Wieers wrote:
>>
>>
>>> I've just written a small dstat plugin to monitor CPU usage per VE. You can
>>> find the plugin in the dstat subversion repository linked from:
>>>
>>> http://dag.wieers.com/home-made/dstat/
>>>
>>> Dstat is much like vmstat, but modular and versatile. So you can extend it
>>> with whatever counters you want to visualize, next to other counters. This
>>> helps to relate counters and find/troubleshoot bottlenecks.
>>>
>>> This plugin can help to find the most consuming VE, or visualize how VE's
>>> are matching up to each other (and the system CPU usage).
>>>
>> Thank you! I actually use dstat on my Gentoo note.
>>
>
> Great :)
>
>
>
>> Speaking of counters, /proc/user_beancounters is of interest to any OpenVZ
>> user. Format is described at http://wiki.openvz.org/proc/user_beancounters.
>> "held" and "failcnt" columns are most "dynamic". You can use the values either
>> directly, or make some consolidated figures based of formulae in wiki.
>>
>
> Well, I was wondering how the beancounters could be of any use. I guess it
> may be useful to see when (and maybe where) they happen, but how would it
> be displayed the most useful ? An aggregated number of all failcnt (either
> global, or per VPS) ?
Makes much sense, especially if using red color to denote that number is
increasing. Makes more sense if used per-VPS.
> That way one can see if any failcnts happen, but
> they'll have to look into the beancounters themselves to know exactly
> which ones happened.
>
> The held-changes are mostly useless to display in a dstat-fashion.
Well, showing kmemsize or privvmpages or physpages is making the same
sense as showing output of, say, "free" in a loop.
> Unless
> maybe if you are a developer ? There's so much information that needs an
> in-depth knowledge.
>
>
>
>> Other thing that might be of interest is /proc/fairsched{,2}. These files are
>> from OpenVZ Fair CPU scheduler. The only problem is looks like the format is
>> not documented (well, not counting the source code).
>>
>> Also, Kirill Korotaev will give us some suggestions...
>>
>
> By any means, if you know what is interesting and how it could be made
> visible on a single line (aggregated or not) we can make different openvz
> plugins depending on the use-case.
>
> Kind regards,
> -- dag wieers, dag@wieers.com, http://dag.wieers.com/ --
> [all I want is a warm bed and a kind word and unlimited power]
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