我可以限制每个Docker容器使用的内存和cpu吗？

Question

I was wondering if there's a way to limit or cap the max memory & processing power used by docker containers on host level. I'm under the impression that the memory options only add provided memory at container launch, but do not limit it permanently.

As I use containers with dotnet apps (hosted dlls), mono'd/wine'd exes, java apps & linux deamons, it would be great if I could make sure that, for instance, continues java memory allocation would not make other containers crash. I'm using java memory options (xms, xmx) for these containers now, and am doing similar to the other containers. I'm lacking a docker based system to manage and monitor cpu & memory. Also, percentile scaling for memory & cpu would be useful, allowing one container to grab a lot of processing power & memory at peak moments. I can monitor this on host process level, not on docker level.

And I'm not even talking about a multi-host setup (swarm, rancher, kubernetes) yet. Or is my question to general?

Answer 1

The docker run command includes options to limit memory and cpu , in particular the -c and -m options.

With a compose file and swarm mode (which can be a single node swarm cluster), these are configured with a resources section per service :

version: '3'
services:
  redis:
    image: redis:alpine
    deploy:
      resources:
        limits:
          cpus: '0.50'
          memory: 50M
        reservations:
          cpus: '0.25'
          memory: 20M

For docker-compose support, you can use the version 2 syntax for a similar result:

version: '2.2'
services:
 test:
    image: busybox:latest
    command: tail -f /dev/null

    cpus: '0.50'
    mem_limit: '50M'