System Administrators can enable JIRA Profiling, extra logging, run the integrity checker, Hercules scans and a number of other potentially CPU intensive operations that can impact the system. Unfortunately the Audit log contains none of these events, making it difficult to rule these actions in or out when investigating performance issues over time.

In particular though, temporary profiling and logging being turned on or off should be recorded:

https://confluence.atlassian.com/display/JIRA/Logging+and+Profiling#LoggingandProfiling-logging_temp