Support for "--cpu-period" and "--cpu-quota"

[Scorpiion]

Hi,

I would like cadvisor to support containers using CFS.

To reproduce, start a container like this (allowed to use 10% of host CPU):

sudo docker run -it --cpu-period=10000 --cpu-quota=1000 ubuntu /bin/bash

Then create a while loop inside (or something else that would use close to 100% CPU):

while [ 1 ] ; do echo "Creating a load..." ; done

In this scenario I would expect cadvisor to show (in the web UI) how much CPU the container used based on it's allowed quota (in the cadvisor view for the container). Right now the percentage showed in cadvisor is calculated with the hosts maximum CPU rather than the containers set maximum CPU, so the above example show ~10% usage for the container (while it's in fact using most of it's capacity).

What are your views on this? It feels it should be possible to calculate the percentage based on the period and quota parameters to get an accurate display for the container?

[vishh]

xref #969

On Mon, Feb 1, 2016 at 7:44 AM Robert Åkerblom-Andersson <
notifications@github.com> wrote:

Hi,

I would like cadvisor to support containers using CFS

To reproduce, start a container like this (allowed to use 10% of host CPU):

sudo docker run -it --cpu-period=10000 --cpu-quota=1000 ubuntu /bin/bash

Then create a while loop inside (or something else that would use close to
100% CPU):

while [ 1 ] ; do echo "Creating a load" ; done

In this scenario I would expect cadvisor to show (in the web UI) how much
CPU the container used based on it's allowed quota (in the cadvisor view
for the container) Right now the percentage showed in cadvisor is
calculated with the hosts maximum CPU rather than the containers set
maximum CPU, so the above example show ~10% usage for the container (while
it's in fact using most of it's capacity)

What are your views on this? It feels it should be possible to calculate
the percentage based on the period and quota parameters to get an accurate
display for the container?

—
Reply to this email directly or view it on GitHub
#1085.

[timstclair]

Is anything else needed here?

[Scorpiion]

Hi @timstclair, if you refer to the merging of #969, yes it is. #969 does not implement this.

See this discussion:
#969 (diff)

[timstclair]

Got it, thanks.

[Scorpiion]

Any updates on this? Is it complicated to add support for this in the web UI?

[vishh]

@Scorpiion none of the maintainers have cycles to work on this feature atm. We can review and take patches though.

[Scorpiion]

Okay, I understand, thanks for the quick reply @vishh.