this post was submitted on 29 Aug 2026
371 points (97.2% liked)
Technology
87649 readers
3024 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related news or articles.
- Be excellent to each other!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
- Check for duplicates before posting, duplicates may be removed
- Accounts 7 days and younger will have their posts automatically removed.
Approved Bots
founded 3 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
In a previous role at an Internet provider, I was the network engineer in charge of the Anycast DNS cache servers. The company made it some sort of point of pride to buy the cheapest hardware possible. I guess that is the beauty of anycast, failure recovery is pretty much automatic.
Anyways, the servers were dead cheap, single power supply, single SSD. They ran BSD, but my system engineer and I wanted to convert them to Linux, so we ran a proof of concept for switching. We ran performance tests against the same server hardware with BSD and with Ubuntu, I think we saw loss on the BSD server at 325k QPS and Ubuntu made it closer to 500k QPS. Oh, we had like 16 of these caches and our peak load network wide across all of them was something like 36k QPS.
It was a pretty cool setup. If I am remembering correctly we used unbound, ExaBGP, IPTables, and a health check script that would trigger the advertisements to our core network. Although we really wanted to switch to Linux (or rather away from BSD), we were primarily driven by the fact that Cisco IOS-XR does not support DNS query IP SLA tests, which we used previously to trigger the route advertisements.
Cool. What is the file size of the DNS database being quarried with each request anyway? My knee jerk assumption is that it's like a petabyte, but the longer I think about it, the smaller it gets.
I actually don’t remember, I was mainly focused on the BGP configurations and data collection for presenting to our leadership. I think unbound allowed you to configure the cache size. Our servers were just cache servers, so if they did not have a record the server would just recurse the request.