Top Banner
Chapter 3 : Distributed Data Processing Business Data Communications, 6e
21

Chapter 3 : Distributed Data Processing

Jan 01, 2016

Download

Documents

cheyenne-hicks

Chapter 3 : Distributed Data Processing. Business Data Communications, 6e. Centralized Data Processing. Centralized computers, processing, data, control, support What are the advantages? Economies of scale (equipment and personnel) Lack of duplication Ease in enforcing standards, security. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Chapter 3 :  Distributed Data Processing

Chapter 3 : Distributed Data Processing

Business Data Communications, 6e

Page 2: Chapter 3 :  Distributed Data Processing

Centralized Data Processing

• Centralized computers, processing, data, control, support

• What are the advantages?– Economies of scale (equipment and personnel)– Lack of duplication– Ease in enforcing standards, security

Page 3: Chapter 3 :  Distributed Data Processing

Centralized Data Processing May Consist Of:

• Centralized Computers• Centralized Processing• Centralized Data• Centralized Control• Centralized Support Staff

Page 4: Chapter 3 :  Distributed Data Processing

Distributed Data Processing

• Computers are dispersed throughout organization

• Allows greater flexibility in meeting individual needs

• More redundancy• More autonomy

Page 5: Chapter 3 :  Distributed Data Processing

Why is DDP Increasing?

• Dramatically reduced hardware costs• Dramatically increased distributed

processing capabilities• Dramatically increased need for new

applications and shorter development times• Ability to share data across multiple

servers

Page 6: Chapter 3 :  Distributed Data Processing

DDP Pros & Cons

• There are no “one-size-fits-all” solutions• Key issues

– How does it affect end-users?– How does it affect management?– How does it affect productivity?– How does it affect bottom-line?

Page 7: Chapter 3 :  Distributed Data Processing

Benefits of DDP

• Responsiveness• Availability• Correspondence to

Org. Patterns• Resource Sharing• Incremental

Growth• Increased User

Involvement & Control

• Decentralized Operation & Control

• End-user Productivity

• Distance & Location Independence

• Privacy & Security• Vendor

Independence• Flexibility

Page 8: Chapter 3 :  Distributed Data Processing

Drawbacks of DDP

• More difficulty test & failure diagnosis• More dependence on communication technology• Incompatibility of components• Incompatibility of data

• More complex management & control• Difficulty in control of corporate information resources• Suboptimal procurement• Duplication of effort• Data integrity• Security

Page 9: Chapter 3 :  Distributed Data Processing

Client/Server Architecture

• Combines advantages of distributed and centralized computing

• Cost-effective, achieves economies of scale

• Flexible, scalable approach

Page 10: Chapter 3 :  Distributed Data Processing

Intranets

• Uses Internet-based standards & TCP/IP• Content is accessible only to internal users• A specialized form of client/server

architecture• Can be managed (unlike Internet)

Page 11: Chapter 3 :  Distributed Data Processing

Extranets

• Similar to intranet, but provides access to controlled number of outside users– Vendors/suppliers– Customers

Utilizing Web technologies

Page 12: Chapter 3 :  Distributed Data Processing

Distributed applications

• Vertical partitioning– One application dispersed among systems– Example: Retail chain POS, inventory,

analysis• Horizontal partitioning

– Different applications on different systems– One application replicated on systems– Example: Office automation

Page 13: Chapter 3 :  Distributed Data Processing

Other Forms of DDP

• Distributed devices– Example: ATM machines

• Network management– Centralized systems provide management and

control of distributed nodes

Page 14: Chapter 3 :  Distributed Data Processing

Distributed data

• Centralized database– Pro: No duplication of data– Con: Contention for access

• Replicated database– Pro: No contention– Con: High storage and data reorg/update costs

• Partitioned database– Pro: No duplication, limited contention– Con: Ad hoc reports more difficult to assemble

Page 15: Chapter 3 :  Distributed Data Processing

Networking Implications

• Connectivity requirements– What links between components are

necessary?• Availability requirements

– Percentage of time application or data is available to users

• Performance requirements– Response time requirements

Page 16: Chapter 3 :  Distributed Data Processing

Database Management Systems

• Structured collection of data for multiple applications to use

• Query language provides uniform access

Page 17: Chapter 3 :  Distributed Data Processing

Database Organization

1. Centralized – Common databases accessed by all processors

2. Replicated - Copy of central database stored at each processor

3. Partitioned – Individual databases for each processor

Page 18: Chapter 3 :  Distributed Data Processing

Centralized Databases

• Advantages

No duplication of data

Little reorganization required

• Disadvantages

Contention among multiple processors accessing a single database

Slow response time

Single point of failure

Page 19: Chapter 3 :  Distributed Data Processing

Replicated Databases

• Advantages

No processor-database contention

Shorter response time

During failure, new copy can be obtained

• Disadvantages

High storage cost

Redundant updates required

High reorganization costs

Page 20: Chapter 3 :  Distributed Data Processing

Partitioned Databases

• Advantages

No duplication of data

Size of database determined by application needs

Short response time

• Disadvantages

Ad hoc management reports must access multiple databases

Page 21: Chapter 3 :  Distributed Data Processing

Networking Implications

• What are the connectivity needs?

• What are the availability needs?

• What are the performance needs?