Resource monitoring per container in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What command shows real-time resource usage of all running Docker containers?

The command docker stats displays live CPU, memory, network, and disk I/O usage for all running containers.

intermediate

How can you limit the CPU usage of a Docker container?

Use the --cpus flag when running a container, for example: docker run --cpus=1.5 limits the container to 1.5 CPU cores.

beginner

What does the docker stats output column 'MEM USAGE / LIMIT' represent?

It shows the current memory used by the container and the maximum memory allowed (limit) if set.

beginner

How to monitor resource usage of a specific container only?

Run docker stats <container_id_or_name> to see resource usage for just that container.

beginner

What is the purpose of setting resource limits on containers?

Resource limits prevent a container from using too much CPU or memory, helping keep the host system stable and fair to other containers.

Which Docker command shows live CPU and memory usage of containers?

A docker inspect

B docker ps

C docker logs

D docker stats

docker stats shows live resource usage like CPU and memory for containers.

How do you limit a container to use only 2 CPUs?

A docker run --cpus=2

B docker run --memory=2

C docker run --cpu-limit=2

D docker run --limit-cpu=2

The --cpus flag limits CPU cores, so --cpus=2 restricts to 2 CPUs.

What does the 'NET I/O' column in docker stats show?

A Network input and output data usage

B CPU network priority

C Number of network interfaces

D Network latency

'NET I/O' shows how much data the container has sent and received over the network.

To monitor only one container's resource usage, you should:

A docker logs <container_name_or_id>

B docker ps <container_name_or_id>

C docker stats <container_name_or_id>

D docker inspect <container_name_or_id>

docker stats with container ID or name shows resource usage for that container only.

Why is it important to set resource limits on containers?

A To speed up container startup time

B To prevent containers from using too many resources and affecting other containers or the host

C To increase container storage space

D To enable container networking

Resource limits keep containers from overusing CPU or memory, protecting system stability.

Explain how to monitor resource usage for Docker containers and why it is useful.

Think about commands and what information they show.

Describe how to set CPU and memory limits on a Docker container and the benefits of doing so.

Consider the flags used when running containers.