Don't be worried so much about
CPU consumption. If the CPU is lucky enough to be 100% busy, 100% of the time, that's probably a good thing.
Instead, look for what the various tasks are
waiting on: what is
delaying them, such as:
- I/O devices
- Memory availability
- Other processes or resources (e.g. query-engine availability; locks
The CPU is always the fastest resource there is, and unless you are ding mongo-heavy scientific computing, it will never be what you are waiting on. Therefore, high CPU utilization is a sign of
health, not sickness. It means that the computer has work to do; that it is using its time productively.