I am running a normal Joomla website on Godaddy's ultimate hosting plan. There is only one site under this plan.
From time to time, my website will be down and giving "refuse to connect" error. When I check the resource usage, I see graphs like this one, which shows constant CPU usage spike on a single day(12/19).
While over a 7 day range, the graph is like this: where you can see there is a physical memory usage spike lately.
I think these must be the reasons my site is up and down. Now my site is a rather small sites with daily pageview of no more than 3k. So the normal visiting shouldn't be causing this usage spikes. I suspect there must be some misconfiguration( which is unlikely because I just use Godaddy's default cPanel) or some degree of breach. My questions are:
- In general, what causes high CPU usage and high memory usage?
- For each of high CPU usage and high memory usage, will they cause the website to be down or just slow?
- I have SSH access, how do I track the reasons for these usage spikes?
Thanks very much for your help!