Question 1)a) Describe briefly the interaction model of distributed system.
b) What is the significance of external data representation? With an example describe CORBA CDR Representation.
c) Consider a simple server that carries out client requests without accessing other servers. Describe why it is generally not possible to set a limit on the time taken by such a server to respond to a client request. What would need to be done to make the server able to execute requests with in a bounded time?
Question 2)a) Describe the TCP implementation of Request Reply protocol.
b) With a diagram describe the role of various modules in the implementation of RMI.
c) A client makes remote procedure calls to a server. The client takes 5 milliseconds to compute the arguments for each request, and server takes 10 milliseconds to process each request. The local operating system processing time for each send or receive operation is 0.5 milliseconds, and the network time to transmit each request or reply message is 3 milliseconds. Marshalling or unmarshalling takes 0.5 milliseconds per message.
Compute the time taken by the client to generate and return from two requests:
(i) if it is single threaded, and
(ii) if it has two threads that make requests concurrently on a single processor.
Question 3)a) With diagrams describe the various server threading architecture.
b) A null RMI delays the caller for 2.0 milliseconds. In the same RMI system, each 1K of user data adds an extra 1.5 milliseconds. A client wishes to fetch 32K of data from a file server. Should it use one 32K RMI or 32 1K RMIs?