Sometimes on dedicated hosting, there can be some scripts that will start consuming 100% of CPU and all the websites will stop working.
We can find out the process list using this command:
It will tell us the process id, but still, we won’t be able to find out which PHP file might have created this process.
sudo lsof -p PID(process id which is taking up cpu)
This will show a list of files that are using this particular process. And anything matching your apache root directory (mostly /var/www/html/….) is the culprit.
** you might need to install lsof using :
sudo apt-get install lsof