Skip to Content

A stick figure smiling

Here's a preview from my zine, How Containers Work!! If you want to see more comics like this, sign up for my saturday comics newsletter or browse more comics!

Image of a comic. To read the full HTML alt text, click "read the transcript".

browse more comics! get the zine!
read the transcript!

processes can use a lot of memory

process 1: I want 10 GB of memory
process 2: me too!
Linux: guys, I only have 16 GB total

a cgroup is a group of processes

every process in a container is in the same cgroup

cgroups have memory/CPU limits

Linux: you three get 500 MB of RAM to share, okay?

use too much memory:| get OOM (“out of memory”) killed

process: I want 1 GB of memory
Linux: NOPE your limit was 500 MB you die now!
process, dead: oh no

use too much CPU: get slowed down

process: I want to use ALL THE CPU!
Linux: you hit your quota for this 100ms period, you’ll have to wait

cgroups track memory & CPU usage

Linux: that cgroup is using 112.3 MB of memory right now

you can see it in /sys/fs/cgroup

Saturday Morning Comics!

Want another comic like this in your email every Saturday? Sign up here!

I'll send you one of my favourite comics from my archives every Saturday.
© Julia Evans 2024 | All rights reserved (see the FAQ for notes about licensing)