I asked them root cause of this load spikes and they said, the Joomla site is the culprit.
And replied this,
So, how do we debug whats going on and how to fix it ?I took a look at the slow log for MySQL. It looks like most of the reported slow logs are related to user/database: joomcd_xxxx It is not the only one, but it is the majority.
That may give an indication as to why the Joomla site is being listed as a high resource usage.
I cant imagine such a small Joomla site trying to take down the server 5 times every hour and Im losing business, clients , money and all of my time on it.