Unit - I Introduction Characteristics of Distributed Systems (DS) : Introduction, Examples of DS, Trends in DS, Sharing Resources, Challenges in DS, System Models : Physical, Architectural and Fundamental models. Remote Invocation : Request Reply protocols, RPC, RMI, Case Study - JAVA RMI. (Chapter - 1) Unit - II Distributed Algorithms Representing Distributed Algorithms : Representation Guarded Actions, Non-determinism, Atomic actions, Fairness, Central vs Distributed Scheduler. Time in Distributed Systems : Logical clocks, Vector clocks, Physical Clock Synchronization, Algorithms for Internal and External Clock Synchronization. Mutual Exclusion : Solution to Message passing systems, Token-Passing algorithms, Solutions on shared memory models, Mutual exclusion using special instructions, Group mutual exclusion. (Chapter - 2) Unit - III Distributed Snapshot Distributed Snapshot : Properties of Consistent snapshot, Chandy-Lamport algorithm, Lai-Yang algorithm, Distributed debugging. Global state collection : Elementary algorithm for All-to-All broadcasting, Termination Detection algorithm, Wave algorithm, Distributed deadlock detection. Coordination Algorithms : Leader Elections, Algorithms like Bully, Maxima finding on the ring, election in arbitrary networks, Election in anonymous networks. Synchronizers : ABD synchronizer, Awerbuch's synchronizers. (Chapter - 3) Unit - IV Distributed Consensus Distributed consensus : Consensus in asynchronous systems, Consensus in synchronous systems, Paxo's algorithm, Failure detectors. Distributed Transactions : Classification of transactions, Implementing Transactions, Concurrency control and serializability, Atomic Commit protocols, Recovery from Failures. (Chapter - 4) Unit - V Group Communication Group Communication : Atomic multicast, IP Multicast, Application layer multicast, Ordered multicast, Reliable multicast, Open groups. Replicated Data Management : Architecture of replicated Data Management, Data-Centric Consistency models, Client centric consistency protocols, Implementation of Data-Centric Consistency models, Quorum based protocols, Replica Placement, Brewer's CAP algorithm. (Chapter - 5) Unit - VI Distributed Discrete-Event Simulation Distributed Discrete-Event Simulation : Distributed simulation, Conservative Simulation, Optimistic simulation and Time warp. Security in DS : Security Mechanisms to thwart various attacks in DS. Social and Peer-to-Peer network : Metrics of Social networks, Modeling Social Networks, Centrality measure in Social network, Community detection, Koorde and De Brujin Graphs, Skip graph, Replication management, Bit-torrent and free riding, Censorship resistance and anonymity. (Chapter - 6)