2) Concurrent Online decisions
Environment in which decisions are made changes constantly, but decisions must be consistent and correct.
State dependent vs. independent:
- A state dependent decision requires knowledge of the current state of the system (who is in a group, what messages have been received already by the group, etc)
- First member of group sets policy.
- User 1 can join only if user 2 is not a member.
- No more then 20 users can join the group.
- A user can only multicast to group y if they are a member of group x.