'Internal server error' when rendering dashboards

CPU usage on our metrics box is at 100% intermittently causing
‘Internal server error’ when rendering dashboards

The only application running on our machine is Docker with 3 subcontainers

  • cadvisor

  • graphite

  • grafana

Machine spec
OS Version Ubuntu 16.04 LTS
Release 16.04 (xenial)
Kernel Version 4.4.0-103-generic
Docker Version 17.09.0-ce
CPU 4 cores
Memory 4096 MB
Memory reservation is unlimited
Network adapter mgnt\

Storage
Driver -> overlay2
Backing Filesystem -> extfs
Supports d_type -> true
Native Overlay Diff -> true

Memory swap limit -> 2.00GB

Here is a snippet from cAdvisor:
image

The kworker and ksoftirqd processes change status constently from ‘D’ to ‘R’ to ‘S’

Question:
Are the machines specs correct for this setup?
How can I get the CPU usage to ‘normal’ levels?