My Firewall Made My Application 10x Slower

Intro Firewalls are great, until they get in your way. I run a simple website that occasionally gets really large traffic spikes, so I like to load test it to know its limits. I’ve been migrating it from GCP to Linode, and during the migration testing I ran into some performance bottlenecks. This has led me on a really long journey of writing my own nftable firewall rules. If you want to skip the firewall background, jump to the debugging section....

October 18, 2022 · 13 min