How to allocate 50% CPU resource to docker container via `docker run`?

Question

I have a 4-core CPU, I want to allocate 50% CPU resource to a docker container.
After reading the docker-run manual and config.go source code.
I still don\'t know ho

Answer 1

It depends on the environment, so there is no straight answer but keep reading.

From the docker run --help command:

-c, --cpu-shares=0         CPU shares (relative weight)

Since Docker is based on cgroups. The CPU will be distributed among the running containers. By default the value is 1024.

cat /sys/fs/cgroup/cpu/docker/cpu.shares
1024

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So, if we have 2 containers, one for the database and one more for the web server

sudo docker run -c 614 -dit --name db postgres /postgres.sh
sudo docker run -c 410 -dit --name web nginx /nginx.sh

Will give 60% to the db container (614 is 60% of 1024) and 40% to the web container.

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For further reading see:

• cpu shares cgroups documentation.
• The cpuset option: --cpuset="" CPUs in which to allow execution (0-3, 0,1)
• Resource management in Docker post.
• Chapter 3 Configuring Docker Containers of the book Orchestating Docker by Shrikrishna Holla.