1. Soft Modularity Enforced modularity –Client / Service

2. Name mapping: - Table - Search gcc f 1 0 … f n 0 Linkerexec

3. gcc f 1 0 … f n 0 D iDiiDi iUiiUi U D D D i U (U U i ) – D – D

4. Procedure Contract Stack Discipline SP 1) Callee corrupts stack. 2) Callee crashes Fate sharing

5. Solution 1: Client / Service Client Service args, procedure Validate msg Unmarshall Run

6. - Modular - Enforced - Comm. Path messages Watchdog Timer - Trusted intermediary - Clients get enforce modularity

7. Implementing c/s org: - Remote Procedure Call (RPC) - Sun RPC - XML RPC SOAP

8. RPC Procedure Call - No fate sharing - Failure vs. extremely slow 1)Exactly-once 2)At-least once idem-potent 3)At-most once - Asynchrony - Intermediary