1 | Under lying themes: cannot design a system that will satisfy every |
2 | user's needs, so must design an extensible system. |
3 | For example: |
4 | Security - Trade-off between security and performance (due to the cost of authentication, encryption, etc.). Rather than providing a fixed level of security, users may choose their own trade-offs by implementing their own policies or by using existing policies via inheritance. |
5 | Fault-Tolerance - Select the level of fault-tolerance needed, and pay for only what they use. By allowing the user to implement there own services or to inherit them from library classes, providing flexibility complemented by a menu of existing choices. |