"Let's use containers, that way we aren't running unnecessary redundant kernels in each VM!"
later
"Oh shit, our containers share a kernel, let's add another kernel to each container to fix this!"
Maybe the next step is that we realize there's so many CPU bugs, that we really just need to give each container their own hardware :)
I am reasonably sure that most of the micro services I write would be very happy running on a 400mhz CPU with a couple hundred megs of RAM, if they were rewritten in native code, or even just compiled to native code instead of being ran on top of Node. Throw it all on a minimal OS that provides networking and some file IO.
How much does it cost to manufacture 400mhz CPUs with onboard memory? Those must cost a few pennies each, throw in a 4GB SSD, preferably using SLC chips for reliability, and a NIC, and sell 4 "machine" clusters of them for ~$100 a pop.
You may want to check out MirageOS[0]. It gives you a library OS with the primitives you say you need, and then all you have to do is import them in your application code as if you are writing your typical OCaml, build the virtual appliance and boot it up anywhere you want.
However, how much is this kind of stuff is actually used at scale today?
From the article:
> For example, off-the-shelf applications such as nginx, SQLite, and Redis running over a unikernel have shown a 1.7x-2.7x performance improvement
That's a pretty healthy boost. Are there any significant efforts close to general use anyone is aware of in this space? (Or good reasons why it's a totally terrible idea and hasn't gone anywhere!)
My memory is fuzzy but ISTR that the people behind seastar/osv moved on to an approach closer to what mrkurt is emphasizing with “container” composition plus firecracker for the environment.