Bug 1614486

Description of problem
======================

Panel "CPU Utilization by Host" on Cluster dashboard (which contains table with single value for CPU utilization for each host) reports the CPU utilization in
wrong/misleading way.

The value reported breaks common expectations and Red Hat recommendations (see
https://access.redhat.com/solutions/2908361).

Version-Release number of selected component
============================================

tendrl-monitoring-integration-1.6.3-7.el7rhgs.noarch

Steps to Reproduce
==================

1. Instal RHGS WA using tendrl-ansible
2. Import Trusted storage pool
3. Select one storage machine from the pool and install stress tool there
4. Run the following command on the selected storage machine:

   stress --cpu ${N} --vm 1 --vm-bytes ${M}G

   where N is the number of cpu of particular machine,
   and M is roughly half of the total memory of the machine (in GB).

   The intended purpose of this command is to:

   * utilize all cpu on each machine to 100%
   * while having significant percentage of system cpu cycles

   Note that for this trick to work, you need a swap space on the machine.

   Let it running while you go on.

5. On the same storage machine, run also the following tools:

   * top
   * sar | tail -n2 | awk '/all/&&!/Average/ { print $1,$2, 100 - $NF}'

6. Go to Cluster dashboard and in Top Consumers section, check
   "CPU Utilization by Host" panel.

Actual results
==============

For the machine where the stress tool is running, the CPU utilization value
from "CPU Utilization by Host" panel is significantly less than 100 %, eg.
about 70 % in my case.

This is because only "user" part of CPU utilization is reported, ignoring the
rest (especially "system" part). As can be checked by commands from step #5:

 * top reports: about 70 % us, about 30 % sy, and zeroes for the others
 * sar command reports 100 %

Expected results
================

The expected CPU utilization value provided by the panel is about 100 % for
the affected storage machine.

Additional info
===============

See Red Hat KB article on the subject: "How to measure cpu usage with a single
value or metric to be used with monitoring and alerting tools?" Available on:

https://access.redhat.com/solutions/2908361

Related issue was found during previous testing phase, but it was resolved in
a different way, as there was no need to limit the chart to a single value:

https://bugzilla.redhat.com/show_bug.cgi?id=1508520