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RMI System Design: Patterns and Pitfalls	O'Reilly Conference On Enterprise Java
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Token-Based Peers

All peers are capable of maintaining state.
At any given moment, only one peer holds the token.
The token permits the owning peer to modify the state.
That peer is responsible for notifying other peers of the changes.
Prevents synchronization problems -- no two peers will attempt to modify the state at the same time.
Peer topology
- Ring: Each peer forwards info to the next.
- Star: The token-owning peer sends changes to all listeners.
If all peers stay apprised of state changes as observers, then only token needs to be passed, and next peer already has full state.

Last modified on 9 Feb 2002 by AO