RPI CPU load gone to 100% after update

Yes, I know we've been here before, but I am stupid and the problem has again happened.

I have a RPI:

Raspberry Pi Model B Rev 2

PRETTY_NAME="Raspbian GNU/Linux 9 (stretch)"
NAME="Raspbian GNU/Linux"
VERSION_ID="9"
VERSION="9 (stretch)"
ID=raspbian
ID_LIKE=debian
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

Raspberry Pi reference 2018-03-13
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 00013d7972122d1304aacda8fff5098f073ceb43, stage5

I have NR installed/running on it.

It would cycle from 36% CPU load to 100% about every 20 seconds. When it did a burst of pings.

That was a pre1.x version of NR.

I updated to 1.0.3 and updated npm as per the recent advisory.

Now the RPI runs at 100% load all the time.

Dashboard 2.19.2
Most/all nodes are up to date.