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

(disco.cloud)
804 points jryio | 3 comments | 21 Oct 25 20:28 UTC | HN request time: 0s | source
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speedgoose ◴[21 Oct 25 21:12 UTC] No.45661785[source]▶
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.

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levkk ◴[21 Oct 25 21:51 UTC] No.45662183[source]▶
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.

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1. 01HNNWZ0MV43FF ◴[21 Oct 25 22:16 UTC] No.45662419[source]▶
It's not just 3 seconds for a button click, every time I've run out of RAM on a Linux system, everything locks up and it thrashes. It feels like 100x slowdown. I've had better experiences when my CPU was underclocked to 20% speed. I enable swap and install earlyoom. Let processes die, as long as I can move the mouse and operate a terminal.
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2. C7E69B041F ◴[21 Oct 25 22:26 UTC] No.45662523[source]▶
This, I'm used to restarting my Plasma 2 times a day cause PHPStorm just leaks memory and it eventually crashes and requires hard reboot.
3. zozbot234 ◴[21 Oct 25 22:43 UTC] No.45662677[source]▶
> It feels like 100x slowdown.

Yup, this is a thing. It happens because file-backed program text and read-only data eventually get evicted from RAM (to make room for process memory) so every access to code and/or data beyond the current 4K page can potentially involve a swap-in from disk. It would be nice if we had ways of setting up the system so that pages of code or data that are truly critical for real-time responsiveness (including parts of the UI) could not get evicted from RAM at all (except perhaps to make room for the OOM reaper itself to do its job) - but this is quite hard to do in practice.