Just to add to this point. I have been running a separate namespace for CI and it is possible to limit total CPU and memory use for each namespace. This saved me from having to run a VM. Everything (even junk) goes onto k8s isolated by separate namespaces.
If limits and namespaces like this are interesting to you, the k8s resources to read up on are ResourceQuota
and LimitRange
.
Despite using Tokio underneath, I think that Actix does NOT do work stealing and uses mostly separate threads:
Given this architecture, I think the article might inaccurate when it says that Actix handlers must be Send + Sync. See also: https://www.reddit.com/r/rust/comments/14cbe1u/why_does_actixwebs_handler_not_require_send/
Actix is a bit weird, but it has been around, and used in production, for a relatively long time.