Flask Droplet Random CPU Spikes

Recently, I got asked about a random CPU spike on a Flask Droplet, which was configured with a single CPU.

This unexpected behavior prompted me to look deeper into potential causes.

Upon investigating, I discovered that the unattended-upgrades feature, which Ubuntu uses to automatically apply security updates, was the culprit behind these CPU spikes.

Here is what I did to further investigate the random CPU spikes.

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Bobby Iliev
Site Moderator
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April 9, 2024
Accepted Answer

To reproduce the problem, I created a Flask Droplet and left it running for a while.

Then I noticed a CPU spike as well in the DigitalOcean monitoring dashboard.

After that I accessed the Droplet via SSH and ran htop:

From the htop output I noticed that the unattended-upgrades process was consuming most of the CPU.

For anyone experiencing similar issues and wondering if unattended-upgrades might be affecting their Droplet’s performance, I recommend checking the logs at /var/log/unattended-upgrades/unattended-upgrades.log*. These logs should provide insight into whether upgrades were being processed during the times you noticed CPU spikes.

By keeping an eye on these logs, you can gain a better understanding of how background processes like automatic upgrades impact your Droplet’s performance, allowing for more informed decision-making regarding your server’s configuration and maintenance.

Besides that, in case of a CPU spike there are a few things that you should always check:

  1. If your Flask application is running behind Nginx or Apache, analyzing the access logs can provide insights into traffic patterns that may be causing the CPU spike. High traffic volume or specific requests that are resource-intensive can lead to increased CPU usage. Check out the script here: Bash Script to Summarize Your Nginx and Apache Access Logs.

  2. To pinpoint which processes are consuming the most resources on your Droplet, you can utilize various command-line tools like top, htop, or atop. You can explore that here: How to Find the Processes That Are Consuming the Most Server Resources.

  3. If you are using MySQL, check out this post here: How to Tweak MySQL/MariaDB Configuration for Increased Performance and Stability?

  4. In some cases, your resources might just not be enough so you should also consider an upgrade:

Hope that this helps!



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