Technical notes, and other ideas.
Always would see the following error mesage on the Power Settings
Performance mode temporarily disabled due to high operating temperature.
Refer: https://askubuntu.com/questions/1419396/how-to-force-enable-performance-mode-in-ubuntu-22-04
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governorEnable with this program instead.
sudo apt update
sudo apt install cpupower-gui
cpupower-guiCheck to see what's the setting
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governorRefer: https://macmetric.com/fix-mds_stores-consuming-high-cpu-usage/
Spotlight is indexing things and it might be indexing an external drive too.
Refer: 20120503 Debugging JBoss 100 Percent CPU Usage.pdf
There's a quick and dirty way of identifying which threads are using up the CPU time on JBoss. Go the the JMX Console with a browser (usually on http://localhost:8080/jmx-console, but may be different for you), look for a bean called ServerInfo, it has an operation called listThreadCpuUtilization which dumps the actual CPU time used by each active thread, in a nice tabular format. If there's one misbehaving, it usually stands out like a sore thumb.
There's also the listThreadDump operation which dumps the stack for every thread to the browser.
Not as good as a profiler, but a much easier way to get the basic information. For production servers, where it's often bad news to connect a profiler, it's very handy.