(a) A distributed conference application provides a shared whiteboard. Each member of the conference has a replica of the whiteboard that is managed by a member of a closed process group. Discuss one approach by which the processes can achieve mutually exclusive access to the whiteboard, prior to propagation of the update to the whole group.

(b) State and explain two concurrency problems in distributed systems. [4 marks]

Question 2

(a) Scalability of a distributed system can be measured in three different dimensions. State and explain any three dimensions with examples. [6 Marks]

(b) Outline the purposes of inter-process communication in a distributed system. [4 marks]

Question 3
(a) Is it the case that any multicast that is both FIFO-ordered and totally ordered is thereby causally ordered? [4marks]

(b) Using appropriate examples explain the differences between passive replication and active replication. [6 marks]

(c) Explain the major differences between RPC and RMI.