[Autoscaler] Multiple available_node_types documentation

[mjrlee]

Description

The ray config allows us to specify multiple available_node_types.

It is not clear from the documentation what happens if you specify multiple node types that are interchangeable in terms of CPU/RAM, or when multiples of one instance type could provide the resources of another instance type.

Link

No response

[scottsun94]

It seems that the ask is to clearly state how autoscaler determines which node types to start and the underlying priority.

[anyscalesam]

@mjrlee responded in #39789 (comment) < can you advise?

[mjrlee]

@anyscalesam I don't think that answers this question, it's still not clear how the ray autoscaler decides which node type to start.

[rickyyx]

What's the usecases for multiple available_node_types here? Maybe just some high-level examples would be really helpful!