The experimental_http3 global option in the Caddyfile has been replaced with global server options, one of which is the experimental_http3 protocol. Docs will be updated shortly. This is still an unstable feature until HTTP/3 is finalized and our upstream QUIC/H3 lib is stable and we’ve decided to keep HTTP/3 enabled in the core by default.
Since it’s not actually released yet, the updated docs haven’t been published (sorry), but we have a new servers option block that configures protocols per-server (or for all servers, as with this example):
[Anyway, there was a typo error that crept into the file that I didn’t notice, but the message displayed was related to this option. When I fixed the typo, it validated with a warning]
Caddy is written in Go, which automatically scales based on available resources, given that the program is written in such a way that supports good concurrency. Caddy is one such program. You have nothing special to do.