(SEM VII) THEORY EXAMINATION 2019-20 DISTRIBUTED SYSTEM

SECTION A – Explanation
 

Section A of the Distributed System paper is designed to test the student’s basic conceptual clarity of core distributed system fundamentals. All questions in this section are compulsory and require brief, precise, and conceptually correct answers. The examiner mainly checks whether the student understands key definitions and fundamental ideas that are repeatedly used in higher-level algorithms and system designs.
 

The questions in this section include the application areas of distributed transactions, definition of fault and failure, definition of global state and consistent global state, explanation of causal order and total order of events, explanation of token-based algorithms, statement of the Byzantine agreement problem, and definition of transparency along with its types in distributed systems. These questions cover transaction processing, fault tolerance, event ordering, mutual exclusion basics, agreement problems, and system transparency.
 

For example, the distributed transaction question checks understanding of applications such as banking systems and distributed databases. Fault and failure questions test reliability concepts. Global state questions evaluate knowledge of snapshot algorithms. Causal and total ordering test understanding of event synchronization. Token-based algorithm questions test mutual exclusion fundamentals. Byzantine agreement checks understanding of fault tolerance in hostile environments. Transparency questions test understanding of how distributed systems hide complexity from users. Answers in this section must be short, accurate, and written in correct technical language. Lengthy explanations are not required, but conceptual accuracy is critical.
 

SECTION B – Explanation
 

Section B evaluates the student’s conceptual understanding and ability to explain distributed algorithms and system control mechanisms in moderate detail. Students are required to attempt any three questions, giving them flexibility based on preparation. The questions in this section are descriptive and analytical in nature.
 

The questions in Section B include explanation of the Lamport–Shostak–Pease algorithm along with how vector clocks overcome the disadvantages of Lamport clocks using an example, discussion of deadlock handling strategies in distributed systems with comparison of centralized, distributed, and hierarchical control organizations, explanation of distributed mutual exclusion algorithms with message complexity comparison, and explanation of election algorithms such as the Bully and Ring algorithms. These questions test understanding of synchronization, deadlock management, coordination, and leader election in distributed environments.
 

For instance, the Lamport and vector clock question tests logical time ordering, causality, and event consistency. Deadlock handling questions test understanding of prevention, avoidance, detection, and recovery strategies. Mutual exclusion questions evaluate knowledge of token-based and permission-based approaches. Election algorithm questions test system coordination and fault tolerance concepts. Answers in this section should be written in a logical flow, beginning with basic concepts and followed by explanation, comparison, and examples. Each answer generally spans about one and a half to two pages.

SECTION C – Explanation

Section C is the most important and highest-weight section of the Distributed System paper. This section tests the student’s in-depth understanding, analytical ability, and practical knowledge of distributed system mechanisms and protocols. Each question has internal choices, and students must attempt one part from each question.

The questions in Section C include explanation of mutual exclusion and its requirements in distributed systems with justification of why it is more complex than in single-computer systems, explanation of deadlock avoidance and the edge-chasing deadlock detection algorithm, explanation of mechanisms for building distributed file systems along with data access operations, discussion of distributed shared memory architecture and related design issues, explanation of checkpointing in message-passing systems with the domino effect, explanation of voting protocols with comparison between static and dynamic voting, explanation of distributed database commit protocols such as two-phase commit, and discussion of consistency and reliability in distributed databases.

These questions require detailed explanations supported by system models, algorithms, and reasoning. For example, mutual exclusion questions test synchronization complexity. Deadlock detection questions test algorithmic understanding. Distributed file system questions test storage and access mechanisms. DSM questions test memory consistency and performance issues. Checkpointing questions test fault recovery concepts. Voting protocol questions test replica control and consistency. Answers in this section must be well structured, technically sound, and written clearly. Each answer generally extends over two to three pages and plays a decisive role in the final score.

Overall Understanding of the Paper Pattern

The Distributed System (RCS-701) question paper is structured to test students progressively from basic definitions to advanced distributed algorithms and system designs. Section A focuses on foundational concepts and terminology, Section B evaluates algorithmic understanding and system control strategies, and Section C tests deep analytical understanding of synchronization, fault tolerance, storage, and consistency mechanisms. Students who understand this structure can prepare effectively by revising definitions for Section A, practicing algorithm explanations for Section B, and mastering long descriptive answers for Section C.

A strong preparation strategy includes understanding event ordering, mutual exclusion, deadlock handling, distributed storage, fault tolerance, and commit protocols. Section C carries the highest weight and must be given special attention to score high marks.