Distributed Systems Overview

Questions and Answers

What are the primary components of a distributed system?

Applications, Frameworks for distributed programming, Hardware, and Operating System

Networking, Middleware, Client/Server architecture, and Messaging protocols

Operating System, IPC primitives, Middleware, and Hardware (correct)

Database management, User interfaces, Frameworks for distributed programming, and Servers

Which of the following is NOT an example of a distributed system?

Manufacturing and process control

Single-user desktop applications (correct)

Banking systems

Federated Databases

What is a key characteristic of the Client/Server system architectural style?

Resources and services are distributed equally among clients.

Information and services are centralized on a single access point. (correct)

All clients share the same user interface.

Clients operate independently without server interaction.

In the context of distributed systems, what does Middleware primarily facilitate?

Communication and data exchange between distributed applications. Signup and view all the answers

Which of the following includes a communication model relevant to distributed systems?

Message passing Signup and view all the answers

What is the primary role of the server process in distributed object frameworks?

It maintains a registry of active objects available to other processes. Signup and view all the answers

In the context of remote procedure calls, what does RPC primarily extend?

The concept of a procedure call beyond process boundaries. Signup and view all the answers

What is the significance of the interface definition in distributed object frameworks?

It serves as a contract for how active objects can be accessed and used. Signup and view all the answers

Which mechanism allows clients to obtain references to active remote objects in distributed object frameworks?

Utilizing a specific addressing scheme to reference the objects. Signup and view all the answers

What is a key characteristic of Service-Oriented Architecture (SOA)?

Services are stateless and can be reused across different applications. Signup and view all the answers

Study Notes

Distributed System Communication

Components communicate through message passing, which includes various communication models.

Components of a Distributed System

Applications: End-user software that relies on distributed resources.
Frameworks: Tools for distributed programming to simplify development.
Middleware: Software layer that facilitates communication and data management.
IPC Primitives: Interprocess communication tools for data control.
Operating System: Manages hardware and software resources.
Networking and Parallel Hardware: Infrastructure for data exchange and processing.

Examples of Distributed Systems

Banking Systems: Handle transactions across multiple locations.
Communication: Email services facilitating message exchange.
Distributed Information Systems: Includes the World Wide Web and federated databases.
Manufacturing Control: Systems for managing production processes.
Inventory Systems: Track goods and supplies across various locations.
General Purpose Applications: Used in educational institutions or office automation.

System Architectural Styles

Client/Server Model: Centralizes information and services at a server accessed by multiple clients for resource efficiency.
Distributed Object Frameworks: Employs Remote Procedure Calls (RPC) for method invocations across networks. Key implementations include:
- CORBA: Common Object Request Broker Architecture.
- DCOM/COM+: Distributed Component Object Model.
- RMI: Remote Method Invocation.
- .NET Remoting: Allows .NET components to communicate across application domains.
Service Oriented Architecture: Utilizes web services for interaction between disparate services.

Remote Procedure Call (RPC)

Extends procedure calls beyond a single process and memory space, enabling interaction between procedures on the same or different systems.

Distributed Object Frameworks

Extend object-oriented programming by allowing distribution across networks, while maintaining coherent operations.
Server Process: Maintains a registry of active objects for client access.
Client Process: Obtains references to remote active objects and invokes methods through these references, with parameters marshaled like in RPC.

Types of Web Services

SOAP Web Services:
- Based on the Simple Object Access Protocol, fully XML-based.
- Utilizes SOAP envelopes for secure communication.
- Standardized by W3C for greater security.
Restful Web Services:
- Architectural style rather than a protocol.
- Treats resources as identifiable entities with unique URIs.
- Supports diverse data formats, including XML and JSON.

Key Components of SOAP Web Services

XML: Standard for data representation and exchange.
SOAP: Protocol for structured message exchange.
UDDI: Universal Description, Discovery, and Integration for locating web services.
WSDL: Web Services Description Language, detailing service interfaces.
Example Implementation: A buyer links to a seller service via UDDI, with service definitions provided by WSDL.

Description

Explore the key components and communication methods of distributed systems. This quiz covers applications, frameworks, middleware, and examples such as banking and email services. Test your understanding of how these systems function and their essential elements.