Because perfect physical clock synchronization is impossible across networks, logical clocks (like Lamport Timestamps) are used to determine the chronological order of events based on causality. Mutual Exclusion
Without a centralized controller, distributed nodes must actively coordinate to maintain system integrity. Time and Global States
A fault in one machine (node) should not bring down the entire system. 2. Key Principles from M.L. Liu's Framework including message queue systems
The fundamental layer of network communication. Sockets provide a low-level programming interface using standard transport protocols like TCP (connection-oriented) and UDP (connectionless). While highly flexible, writing applications directly on sockets requires manual data serialization and protocol management. The Client-Server Paradigm
| | Topic | Key Concepts & APIs Covered | | :--- | :--- | :--- | | 1 | Introduction | Definition of distributed computing, basic network & OS concepts, software engineering principles, security, fault tolerance, and the Internet. | | 2 | Interprocess Communication | Basic communication model, primitives (connect, send, receive), connection-oriented vs. connectionless communication, data marshalling, and serialization. | | 3 | Distributed Computing Paradigms | An overview and historical evolution of various paradigms for distributed computing. | | 4 | The Socket API | Stream-mode (TCP) and datagram (UDP) sockets, implementing clients and servers, and secure sockets using the Java Socket API. | | 5 | The Client-server Paradigm | Connection-oriented and connectionless client-server models, iterative vs. concurrent servers, stateful vs. stateless servers. | | 6 | Group Communications | Unicast vs. multicast, basic group communication model, the Java Multicast API, and reliable multicast. | | 7 | Distributed Objects | A comparison of message passing and distributed objects, covering Remote Procedure Call (RPC) and Remote Method Invocation (RMI). | | 8 | Advanced RMI | Advanced concepts in Java RMI, including stub downloading, security policies, and callbacks. | | 9 | Internet Applications | Basic components of the web (HTTP, HTML, web servers, browsers), CGI, and maintaining HTTP session state. | | 10 | CORBA | The Common Object Request Broker Architecture (CORBA) and its related details in Java. | | 11 | Internet Applications (continued) | A continuation of the previous chapter, elaborating on different applications that exist on the Internet. | | 12 | Advanced Paradigms | An overview of advanced distributed computing areas, including message queue systems, mobile agents, network services, object spaces, and collaborative computing. | and collaborative computing.
Designing a distributed system is notoriously difficult due to the unpredictable nature of networks. 1. Synchronization and Concurrency
Fundamentals, history, and an overview of major paradigms . including stub downloading
M.L. Liu's textbook is widely praised for its balance of theoretical foundations and practical Java-based programming examples. Key Learning Outcomes
Even if you find a pirated PDF of "Distributed Computing Principles and Applications" by M. L. Liu, the value is in the clarity of the Java examples. However, the best investment is a legal digital copy or a used physical edition (the 1st edition from 2004 is still perfectly valid; distributed computing principles do not age like web frameworks).