1) (5 pts.) Describe two differences between caching and replication based on their characteristics? 2) (5 pts. One of the challenges in RPC is passing parameters using callby-reference. Write a strategy that can be used to address the problem of passing a parameter using call-by-reference in RPC. 3) (5 pts.) One approach to provide location transparency is to use name servers or binders. Can this approach be used to provide migration transparency? Explain. 4) (5 pts.) Reliable communication is defined in terms of validity and integrity. a) Explain what integrity and validity mean in the context of reliable communication in distributed systems. b) Briefly describe mechanisms that are used to ensure validity and integrity in a TCP communication. 5) (4 pts.) Can a telephone no. be used as a (true) identifier for a person? Justify your answer using properties of a (true) identifier. 6) (7 pts.) A distributed system with four processes, P to P4 uses vector clocks for synchronization. At a given time, process 3, Ps, receives a message, m, with a time stamp (1,4,4,3], ts(m)=(1,4,4,3), from process 2, P, while its vector clock is (3,2,5,0), (i.e., VG=(3,2,5,0]). a) (4 pts.) What information does have at the time of message receipt? b) (4 pts.) What will do to the received message from P? Explain your answer. 7) (4 pts.) Compare the performance of mutual exclusion algorithms (centralized, decentralized, Ricart and Agrawala's, and token ring) in terms of number of messages exchanged to enter and exit a critical region using a table Justify the number of messages you used to describe the performance of each algorithm. 8) (5 pts.) In a system which implements a two phase commit protocol, a participant, P, which voted to commit a transaction, is blocked at its READY state. If the coordinator crashes before sending the global vote to P and P timeout, what could do to make a decision on the particular transaction? Explain