UNIVERSITY EXAMINATIONS: 2018/2019
EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY
BIT2303 DISTRIBUTED SYSTEMS
FULL TIME/PART TIME/DISTANCE LEARNING
DATE: APRIL, 2019 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE
a. Differentiate between the following:
i. Blocking and non-blocking semantics [2Marks]
ii. Differentiate between RPC and RMI [2Marks]
iii. Multiprocessor and multicomputer [2Marks]
iv. Tightly coupled systems and loosely coupled systems. [2Marks]
b. Briefly explain threads in distributed system. [3Marks]
c. Briefly explain the mechanisms for implementing Remote IPC [6Marks]
d. Explain Higher-level and Lower-level protocols of the OSI models. [6Marks]
e. Define CORBA and give the advantages of CORBA as used in distributed system.
[7Marks]
QUESTION TWO
a. Define process migration, explaining what it involves in a distributed system. [4Marks]
b. Briefly explain six desirable features of a good process migration mechanism. [6Marks]
c. Discuss the mechanisms of deadlock detection in a distributed system. [6Marks]
d. Discuss the functions of remote IPC. [4Marks]
QUESTION THREE
a. Discuss the following distributed system models
i.Three tier architecture [2Marks]
ii. Mobile code [2Marks]
iii. Mobile agent [2Marks]
b. Briefly explain three metrics of a scalable system. [6Marks]
c. Describe the issues in Concurrency and solutions to these concurrency problems
[8Marks]
QUESTION FOUR
a. Briefly explain the file models and accessing models, as used in file management.
[4Marks]
b. Describe the benefits of file replication in a DFS. [7Marks]
c. Identify the file properties that influence fault tolerance. [3Marks]
d. Outline the major causes of changes in a directory service. [6Marks]
QUESTION FIVE
a. Discuss the methods of clock synchronization [6Marks]
b. Explain Lamport timestamps. [4Marks]
c. With the aid of a diagram discuss the relative benefits and limitations of three commonly used
models for configuring a distributed computing system. [10Marks]
