One of our m1.small EC2 instances, running a Node.js web server, regularly gets some CPU spikes. It doesn't seem to matter what the peak CPU reaches, but whenever our traffic approaches the max for the day, it spikes, and the same happens when it starts to decline.
This happens when it approaches 80% on a weekday, or even if it appraoches 40% at the weekend.
Does anyone have any idea what could be causing this? Or how I could debug this and stop it from happening? I've checked the cron jobs and theres nothing that would cause this.
I've attached a graph to help me explain the scenario.