What are some memory recommendations for a Nebula cluster? 16 GB 32GB? What are some typical configurations?

It depends of your data size and what queries you will execute. But in general more memory the better. I have cluster with 8 processing nodes and 2 query nodes, and I have 32 core nodes with 256GB memory. My data size is large with 60B vertices and 300B edges.

That’s a lot of vertices