How do I find out what's causing increased CPU usage on my Linode?

I recommend using the 'top' command to find out what's using the most CPU time on your Linode. We have a guide on the 'top' command here:

Using top to Monitor Server Performance

From there, checking the log files for the service may help narrow down the exact cause. Most services have log files in the /var/log directory. If the service is Apache, PHP, or MySQL the increase in CPU usage may be from an increase in website traffic.

don't forget using pidstat and other tools too

some useful links

• https://www.thegeekstuff.com/2014/11/pidstat-examples/
• https://linuxaria.com/howto/linux-terminal-pidstat-know-everything-about-your-processes
• https://www.tecmint.com/sysstat-commands-to-monitor-linux/