If you receive a notification related to high CPU from Bunnyshell then we recommend that you approach this in a systematic way.
If the alert is temporary (the service recovered itself fast) it is possible that a process was using more resources for an operation in which case, there is nothing you should do since this can be absolutely normal. For example, the backup operation can trigger such an alert since compressing the backup is a CPU intensive process.
If the alert is continuous then please SSH your Virtual Machine [link to article] and run the htop utility:
This utility will offer you insights into which process is taking up the resources so that you can determine if this is normal or abnormal. You can sort by CPU by clicking on that column header.
Using htop you can perform some actions such as stopping an offending process. This is achieved by selecting the process (either with the mouse or using the arrow keys) and pressing F9 to get the possible actions.
Highlight 15 SIGTERM (signal terminate) to gracefully request to stop the process or 9 SIGKILL (signal kill) to forcefully shut down the process. When you are content with your selection press the Enter key.
Note: Please attempt to find out first what is the purpose of the process before you terminate it. A simple google search of 'process_name high CPU' will provide the insights needed for you to make an informed decision.