problem 1)a) Briefly describe failure model of a distributed system.

b) Describe three different RPC exchange protocols.

problem 2) Outline the design scheme that make the IP multicast a reliable group communication.

b) Discuss the design issues for Remote Method Invocation.

c) Describe how a forwarding observer may be used to enhance the reliability and performance of objects of interest in an event service.

problem 3)a) With diagram describe different architectures for multi-threaded servers.

b) Network transmission time accounts for 20% of a null RPC and 80% of an RPC that transmits 1024 user bytes (less than the size of a network packet) . By what percentage will the times for these two operations improve if the network is upgraded from 10 megabits/second to 100 megabits/second.

c) Describe two implementations of protection domain in distributed system.