Every so often my linode (which hosts a low traffic Rails app) will not respond to web requests for a few minutes. I just get a timeout. I have started seeing a pattern, where this will happen at a particular time each week. This doesn't correspond with any cron jobs I have set up.

I've checked my logs and see regular attempts to SSH into my linode around the same time that the linode becomes unresponsive. I've installed fail2ban, which is doing its job, but my understanding is that these attempts wouldn't be enough to cause a bottleneck.

My graphs are good - CPU average of ~4%, and I/O rate average 6.55.

Is there something else I should be looking for here? Or another way I can diagnose this issue?

Thanks!

What's your RAM/SWAP usage look like? Do you see a spike in swapping (in/out) during those times as large amounts of IO?

(Check the linode IO graphs, there should be a separate line for swap IO)

Thanks kyhwana,

The swap IO is 0 all the time. It never registers a beat.

Move your ssh port, smaller log files and bots will move on to easier targets.