Anybody has a hint? I didn't change anything in the machine (except for the security updates), and the sites hosted there didn't suffer a significant change in connections.
May be Google changed something in their infrastructure? Coincidentally, it was an issue with the Cloud DNS ManagedZone these days: they charged me with $ 920 for half month usage, and it was an error (they counted thousands of weeks of usage too) so they recently changed back to $ 0,28. May be there was some process that indeed used the Cloud DNS by error and thus consumed CPU power, and they corrected now?
I wish to know what is happening from someone that knows what going on in GC. Thank you.