17 Čec
2025
17 Čec
'25
10:15
This operation (performed by knotd) is
single-threaded, therefore the
measured load on your multi-CPU-core machine might not seem utilized.
Could you please confirm that one CPU core is running on 100% during the
commit?
It's a bit hard to tell because it's only 2 seconds, but I believe yes, this is
the case.
It is true that some operations modifying the set of
configure zones
lead to complete re-build of the zone tree, therefore the time needed
depends of the total number of zones, even when they are otherwise
unaffected. Daniel already told that he will check if/why this is also
the case.
Anyway, are 2 seconds really that bad? It seems nice to me :) If many
zones are casually added/removed in your setup every minute, it would be
wise to group them into batches -- not only for performance/timing
reasons. Could you please confirm that adding/removing for example 100
zones takes roughly the same time?
Yes, doing multiple domains at once takes a similar amount of time, though it does
increase a bit as the number of domains increases.
Batching is something we try and do, but it still feels a bit odd that every addition or
deletion of even a single domain always takes at least 2 seconds.
By the way, we would love to hear about any other
challenges/bottlenecks
in your setup.
Overall, knot has worked very well for us. If you're interested, last year I wrote up
a fairly detailed post about our migration from powerDNS to knot
<https://www.fastmail.com/blog/moving-fastmail-dns-to-knot/>. Feel free to ask me
any questions if you'd like more details.
Cheers
--
Rob Mueller
robm(a)fastmail.com