Here my logic,
One server can only bind to one port. So the second server will not be successful because the port is already bind! If you are using ServerSocket.
If you are using RMI, you have to rebind the name to the registry, and back to the same point of having one instance at the registry. So there is no issue. If someone deliberately binds to another name, the client has to know the name to connect. This is beyond the concerns of the developer.
Having one instance of a class running doesn't mean you must have a Singleton design
pattern. Implementing Singleton unnecessary may have impact on scalability.
2 cents and Best Regards
[ January 29, 2004: Message edited by: Frankie Cha ]