Technical Tip: How to collect the information to troubleshoot the high CPU usage on FortiADC

Prerequisite:

• Log into FortiADC SSH/CLI using an admin account.
• Collect the information live during the FortiADC high CPU usage occurrence.

Steps:

• Check on the FortiADC GUI Dashboard page. Check for the Resource Usage graph to identify when the high CPU usage started. Check the Server Load Balance and Global Load Balance graph to see if there is an excessive amount of traffic increased during the period. Take a screenshot of the dashboard graphs.

• Log into the FortiADC SSH shell and run the commands below to collect the CPU usage information:

get system performance

• The command shows the average CPU usage for the moment.

diagnose system top

• The command shows the list of processes and the CPU usage of each of the processes, the usage panel auto-refreshes every 5 seconds.
• Find the process that has the highest CPU usage.
• It is recommended to log the putty session before running the command so that the CPU usage records will be logged.
• Keep the command running for 1 to 2 minutes, and press ‘q’ key to exit the ‘top’ screen.

diagnose system perftop

• Similar to ‘top’, the command shows the processes and the CPU usage.
• Keep the command running for 1 to 2 minutes, and press ‘q’ key to exit the ‘perftop’ screen.
• Download the all-in-one debug file and upload the debug file to the ticket for the TAC engineer to analyze.

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