Replacing a $3000/mo Heroku bill with a $55/mo server

Looking at the htop screenshot, I notice the lack of swap. You may want to enable earlyoom, so your whole server doesn't go down when a service goes bananas. The Linux Kernel OOM killer is often a bit too late to trigger.

You can also enable zram to compress ram, so you can over-provision like the pros'. A lot of long-running software leaks memory that compresses pretty well.

Here is how I do it on my Hetzner bare-metal servers using Ansible: https://gist.github.com/fungiboletus/794a265cc186e79cd5eb2fe... It also works on VMs.

Yeah, no way. As soon as you hit swap, _most_ apps are going to have a bad, bad time. This is well known, so much so that all EC2 instances in AWS disable it by default. Sure, they want to sell you more RAM, but it's also just true that swap doesn't work for today's expectations.

Maybe back in the 90s, it was okay to wait 2-3 seconds for a button click, but today we just assume the thing is dead and reboot.

How programs use ram also changed from the 90s. Back then they were written targeting machines that they knew would have a hard time fitting all their data in memory, so hitting swap wouldn't hurt perceived performance too drastically since many operations were already optimized to balance data load between memory and disk.

Nowadays when a program hits swap it's not going to fallback to a different memory usage profile that prioritises disk access. It's going to use swap as if it were actual ram, so you get to see the program choking the entire system.

This is really interesting and I've never really heard about this. What is going on with the kernel team then? Are they just going to keep swap as-is for backwards compatibility then everyone else just disables it? Or if this advice just for high performance clusters?