CPU spikes in Apache
I have 6 wordpress websites running on my Ubuntu Linode. Now frequently Longview sees Apache2 spiking 100% CPU which causes slow website performance.
My guess it's a plugin or basically just one wordpress installation that causes it. My question is how can I find out which out of the 6 domains is causing this CPU spike?
It's been going on for a few days now…
In either case, if you are only using WordPress, try nginx + php5-fpm.
I've also added deny from all in .htaccess per domain to see if that would stop the high cpu. Didn't have any result.
The 100% CPU spikes happen every day at 11:45 till around 12:15. Very consistent every day. Mornings from like 9:00 to 9:15 as well.
What other options do I have to find out where this comes from?
So, if you see high CPU usage in Apache, there must be http requests to justify the load.
Try making histograms of web visits. For example, number of web requests in one-minute intervals, or in five-minute intervals.
At least one of your six domains should have a peak at the same time you see high CPU load.