Increased DiskI/O and CPU usage
Hello All!
I am hosting a web app with multiple docker containers. After my last docker stack deploy the cpu usage increased constalty to avg 17% (from max 2%) and the Disk I/O to avg 120 blocks/s (from max 2), and I have no idea why. Probably this is not big of a usage, but this is my first ever web hosting, and my website is not popular (no one knows about it) so I am sure its not because it got popular all of the sudden. I would like to know if I screwed something up or my site is getting attacked.
Can you please help me how I could check what is using the CPU or the Disk constantly?
Thank you very much!
Best regards,
Miklos
2 Replies
tlambert
Linode Staff
✓ Best Answer
This reference page from the docker documentation has information on how to use the docker stats command to display CPU and I/O metrics for your containers. You should be able to get a pretty good indication of which containers are using your resources from that command.
If, by chance, there is another process outside of docker that is the culprit, another answer from this site shares some resources that may be useful for investigating what else is running on your Linode. Utilizing commands like top and ps aux with the proper syntax can be incredibly helpful.
With this in mind, I'd like to point out that averaging 17% CPU usage is not anything to be concerned about, unless of course you are experiencing degraded performance. Even a Nanode plan should be able to handle sustained CPU usage of 80% with spikes of higher. If you are noticing a drop in performance with your metrics being at such a low level, I suggest opening a support ticket so a member of the Support Team can look into your Linode's performance a bit further. They would be able to rule out the infrastructure (network connectivity or hostload) having a negative affect on the instance.
Dear Tlambert,
Thank you very much, this was quite helpful!
Best regards