How to find if server is single node or multi node

Oracle apps can be implemented on single node or multi node.
In single node-database,CM,Reports,forms,Apache are all on one single server only.
In multi-node we can have these components on different servers.
A typical 2-node server has the following->
1st node-database,CM,reports
2nd node-forms,Apache
A typical 3 node server has the following->
1st node-database
2nde node-CM,reports
3rd node-forms,Apache
Here's how to find out if the server is single node or multi node->
1-select * from fnd_nodes(It also contain column like "support_forms","support_web","support_web","support_db","support_admin" which identifies which tier it supports)
2-OAM-oracle applications manager
3- context file(Has variables s_isDB, s_isAdmin, s_isWeb, s_isForms,s _isConc which identifies which tier it supports)