I think there is only that page, which could probably be expanded on
However there are only 4 node types - master, data, client and tribe;
- Master only nodes take place in updating cluster state as well as master elections. They should never handle query or index loads.
- Data only nodes store data that is indexed into Elasticsearch. These can also handle querying and indexing.
- Client only nodes are used as load balancers for indexing and searching.
- Tribe nodes are akin to cross-cluster client nodes, in that they can query more than one cluster. Think federated search.
Regarding placement, we generally recommend separating roles out for larger clusters, >10 nodes, but that's arbitrary and very use case dependant.