What could be causing this CPU load pattern?

Question

linux

The box on DigitalOcean draws an unusual CPU load graph:

These peaks do not correlate with either external/private network or disk operations. I can't figure out what it could be from the logs.
Maybe you came across similar “drawings in a cornfield”?
The teeth are irregular. Those. does not depend on krone. The intervals between the peaks in these teeth are also inconsistent.
On the nginx, php-fpm, redis, mysql server. I looked at the requests to the web in the logs - they cause uniform noise in the load.
How can you catch a process eating sometimes more than 100% cpu?
Same question on SO

Answer 1

Put atop in logging mode - you can see after the fact what processes are loading the processor.

Answer 2

Put newrelic, there will be an answer in 1 hour.