docker-cfs-quota

README

docker-cfs-quota

docker container to test cfs quota fixes in the linux kernel. infos:

• https://github.com/kubernetes/kubernetes/issues/67577
• https://github.com/zalando-incubator/kubernetes-on-aws/pull/923
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=de53fd7aedb100f03e5d2231cfce0e4993282425

go code borrowed from (see readme there for more info):

• https://gist.github.com/bobrik/2030ff040fad360327a5fab7a09c4ff1

run on your docker host with 200 millicpu via:

docker run -it --rm --env CFS_SLEEP=200ms --env CFS_ITERATIONS=50 --cpus 0.2 monotek/docker-cfs-quota

or in kubernetes:

kubectl run --generator=run-pod/v1 -it --rm cfs-quota-test --image=monotek/docker-cfs-quota --env=CFS_SLEEP=200ms --env=CFS_ITERATIONS=50 --limits=cpu=0.2 --requests=cpu=0.2

Default values of the go app can be changed via env vars:

• CFS_SLEEP
  • defaults to 100ms
• CFS_ITERATIONS
  • defaults to 25

Results:

• If burn times are going above 5ms your kernel is throttling!