I have an EC2 server based on Ubuntu 18.04. With CloudWatch detailed monitoring enabled I'm seeing spikes of Disk Read Operations that last less than 1 minute (shown as 1-minute spikes on the graph) and happen every 2-7 minutes (~12x / hr):
I have experience using iotop to diagnose things like this, but in this case it's showing me that everything has "0.00 B" values for "Disk Read" (cmd: iotop -a -o). After iotop failed to give me anything useful, I searched for similar tools, trying atop, nmon, dstat, and htop (which is a little overwhelming to use and I'm not confident I gave it a fair chance to diagnose). As best as I could tell (having little-to-no experience with these other tools), all of them showed zero disk read I/O - note that every tool was run during at least 1 of the CloudWatch-reported spikes.
I'm a bit baffled by this and unsure how to proceed. The Disk I/O is not massive, but its regularity begs explaining/understanding. Any suggestions, explanations, or guidance are appreciated.
