Was wondering, whether anyone tried to run the combo, and how it performs?
 yes generic question, but about the combo of OH AND Grafana, on a rPi4 with 4GB. Or more specifically, will the 4GB allow for the two packages to work properly together, w/o the issues seen on smaller machines (most of which where memory related).
Generic answer? It should perform same/better.
I have a rPI3b+ which only has 1GB SRAM and it works just fine.
Do you have a very heavy setup with over X Things/Items and you are worried?
Just assuming from the raw specifications:
There is a known issue with PhantomJS that Grafana uses to render their static images charts. The library runs amok consuming all the CPU and RAM eventually causing the kernel to start killing other processes, including openHAB.
If you don’t render static images everything should be fine though. If you do, I think it’s an open question as to how it works on the RPi 4.
So how do people solve this issue? I initially thought to run grafana on another machine (if that even works). But if memory grabbing is the issue, no matter how much memory one has, it will fall over eventually.
It’s mainly a problem with RPis. It runs just fine on Intel and and processors. But Grafana has dropped PhantomJS support even there for new versions. See Grafana Image Renderer.