Improve docs for scaling & architecture

[xxchan]

This is from an incident: User only scaled compute node, but not compactor.

We are redesigning scale portal on cloud. We should also improve doc.]

https://www.notion.so/risingwave-labs/recurrency-scale-bottleneck-2014-11-06-13cf0d69cb7680ae8fabcff1d50ef021?pvs=4

Ah I was wondering what the relationship between those was. The documentation on it is… light. I’ll try it again with more compactor cores

What about the relation between CN, compactor, meta, and FE? Are there other scaling transitive effect I should be aware of?

By the way, do you have any other specific feedbacks about what information is missing on what pages?

I think for this specific topic the architecture page tells you very little about the different component interactions. It just shows a diagram of boxes pointing to other boxes and a high level overview. For example I had no idea that CN can be impacted by the compactors.