Module-1--Distributed Computing Concept

Distributed Computing

  • Definition: Computing performed in a distributed system.

  • Early Computing: Initially centralized computing on a single processor.

  • Distributed System: A collection of independent computers, interconnected via a network, capable of collaborating on a task.

Examples of Distributed Systems

  • Network of Workstations (NOW): A group of personal workstations connected to servers.

  • The Internet: Global interconnected network.

  • Intranet: A private network within an organization, safeguarded by firewalls.

Large-Scale Distributed Systems

  • Example: eBay, as highlighted in a 2007 report.

Small-Scale Distributed Systems

  • Home Networks: Allow control over heating, security, and entertainment through a Control Server, utilizing existing infrastructure (cable TV/power lines).

  • Components:

    • Control Server: Central hub, accessible via remote or internet-enabled devices.

    • Service Providers: Monitor home systems and manage repairs.

    • Universal Remote: Access systems from home or via mobile devices.

Components of a Distributed System

  • Workstations: User computers for individual computing tasks.

  • Server Machines: Provide resources and services.

  • Personal Assistance Devices: Handheld devices connected wirelessly.

Power of the Internet

  • User Statistics:

    • 60 million households use computers (1998).

    • 80 million workplace users (1998).

    • 84% find the internet indispensable.

  • Traffic Growth:

    • Internet backbone's capacity doubles every 100 days.

    • Data traffic is increasing at 125% per year, voice traffic significantly less ( less than 1% total by 2007).

Internet Growth and Capacity Stats

  • Unique Domain Names: 12,844,877 registered (as of 1999).

  • Host Computers: Grew from 80,000 in 1989 to 56.2 million in 1999.

  • Total Amount of Data: In 1999, the internet featured billions of pages and bytes of text/images.

Email and Traffic Growth

  • Email Volume: An average U.S. consumer receives 1,600 commercial emails in 2005, a sharp increase from 40 in 1999.

  • Web Hits: Averaged one billion per day in the U.S. by late 1999.

Historical Internet Access

  • 1993: 90,000 Americans online, growing to 19 million by 1997, and 118.4 million by 1999.

Internet Usage by Percentage

  • 1998: 28% of Americans online, increasing to 91% by 2005.

New Internet Users and Usage Trends

  • Early 2000: 5 million new users in Q1 2000; average user session data provided.

Email Statistics

  • 1998: 101 billion pieces of mail vs. estimated 618 billion to 4 trillion emails sent.

  • Increase in Online Hours: 1997 saw 28 hours per capita, which jumped to 192 by 2003.

Worldwide Internet User Growth

  • 1998: 95 million users; grew significantly through 2005, with the U.S. leading.

Wireless Internet Access

  • 2003: 61.5 million Americans expected to use wireless devices, a considerable increase.

Network Architecture and Standards

  • Protocols: Rules for data exchange on networks. The OSI model has seven layers.

TCP/IP Protocol Suite

  • Functionality: Key architecture of the internet, guiding data transmission between hosts.

Network Resources

  • Definition: Hardware and software resources available in a distributed system (includes services).

Addressing and Identifying Network Resources

  • Challenges in unique identification of resources like email and web documents.

Internet Addressing Scheme (IPv4)

  • Each address is 32-bit long, divided into classes (A to E).

Internet Address Representation (Human Readability)

  • Dotted-decimal notation is used for IP addresses for user friendliness.

Domain Name System (DNS)

  • Maps symbolic names to Internet addresses. Controlled by several DNS servers.

Top-Level Domain Names

  • Categories include .com, .org, .edu, among others; country codes exist for global standards.

Event Synchronization in IPC

  • Requirement for processes in distributed computing to synchronize sends and receives.

Blocking and Deadlocks in IPC

  • Illustrates issues with process communication, including handling deadlocks effectively.

Data Representation in IPC

  • Binary data stream representation considerations across systems, emphasizing standardization.

XML and Data Marshalling

  • XML serves as a text-based method for data interchange, ensuring universally readable data formatting.