So that’s generally not very likely. You’re going to have some time of day effects that are shared but true “peak” tends to be service dependent rather than something all your services experience simultaneously from what I’ve seen (YMMV).

Killing “idle” processes is also extremely expensive because you have to restart the process, reload all state, and doing graceful handoff is tricky.

It’s good to have graceful handoff for zero downtime upgrades, but I still say having your allocator return RAM is the cheapest and easiest option and something good modern allocators do for you automatically.