Data Structures unit I just look to learn the contents

hello

1. CS6601 – Distributed Systems

2. Unit I Examples of Distributed Systems–Trends in Distributed Systems – Focus on resource sharing – Challenges. Case study: World Wide Web.

3. Distributed Systems - Definition A distributed system is one in which components located at networked computers communicate and coordinate their actions only by passing messages. The components interact with each other in order to achieve a common goal.

4. Examples of Distributed Systems Web Search Massive Multiplayer Online Games (MMOGs) Financial Trading

5. Web Search For web searches – search engine-representing the contents of search engine Search the entire database to provide information is the complex task of search engine It has a high infrastructure: Network of computers Distributed file systems – heavily optimized for the search Distributed storage giving access to the large data set Lock and agreement A program model

6. Massive Multiplayer Online Games MMOG Large number of user interaction (50,000 simultaneous players) Persistent virtual world Examples of virtual games Fast response time for the users experience as in real world Architecture used – client server – state of the world maintained in the centralized server supporting large number of clustered clients Distributed architecture – portioning of regions to maintain servers

7. Financial trading Needs wide range of access to wide range of information Events – communicating and processing items of interest i.e. distributed event based systems It covers both sellers and buyers

8. Trends in Distributed Systems Changes in trends of distributed systems makes out significant changes Emergence of pervasive networking topologies Emergence of ubiquitous computing – user mobility Increasing demand for multimedia services The view of DS as system as utility

9. Pervasive networking and the modern internet Interconnected computers with wide communication technologies – WiFi , WiMAX, Bluetooth, 3G, 4G, LTE, VoLTE i.e. Pervasive network Services – WWW, File transfer, email etc. Firewall – protection to intranet – unauthorized users avoidance Backbone – high transmission capacity, employing satilite connections, fibre optic cables, high-bandwidth circuits

10. Mobile and Ubiquitous Computing Device miniaturization and wireless technologies increases the number of devices attached to the network Eg . PDA, Mobile Phones, Smart gadgets Connectivity provided among these devices is made successful by Mobile computing – computing task on user movement other than home network Location-aware or context-aware computing – providing the access to the required contents irrespective of their location Ubiquitous computing – harnessing small, cheap computational devices in the near physical environment

11. Distributed multimedia systems As DS is growing in a matured manner, it is promoted as utility and is applied as physical resources and logical resources Physical resources – storage and processing made available through network Software services – made available through cloud computing Cloud Computing – an internet based application for storage and computing – computing as utility Cluster Computing – interconnected computers to provide integrated high-performance computing capability – mass storage, rich applications

12. Focus on resource sharing Resource sharing Hardware resources – printers, files and others Search engine – provides online server resources to multiple users simultaneously Computer Supported Cooperative working (CSCW) - a group of users who cooperate directly share resources such as documents in a small, closed group Service - a distinct part of a computer system that manages a collection of related resources and presents their functionality to users and applications

13. Challenges in Distributed Systems Major challenges faced in a distributed system are : • Heterogeneity • Openness • Security • Scalability • Failure Handling • Concurrency • Transparency • Quality of Service

14. 1. Heterogeneity