1. Middleware Technologies
Robert Orfali

2. MIDDLE WARE TECHNOLOGIES
B.TECH III YR II SEMESTER
UNIT 1 PPT SLIDES
TEXT BOOKS:
1.Client/Server programming with Java and CORBA Robert Orfali and Dan Harkey, John Wiley & Sons,SPD 2nd Edition
2. Java programming with CORBA 3rd Edition, G.Brose, A Vogel and K.Duddy, Wiley-dreamtech, India John wiley and sons

3. INDEX UNIT 1 PPT SLIDES S.NO. TOPIC LECTURE NO. PPTSLIDES
1. Introduction to client server computing L L1. 1 TO L1.4
2. Evolution of corporate computing models L L2. 1 TO L2.5
from centralized to distributed computing
3. client server models L L3. 1 TO L3.4
L L4. 1 TO L4.4
Benefits / pitfalls client server computing L L5. 1 TO L5.5
5.. REVISION L6

4. UNIT1 SYLLABUS
Introduction to client server computing: Evolution of corporate computing models from centralized to distributed computing , client server models. Benefits for client server computing, pitfalls of client server programming.
lecture 1 slide 2

5. What is client/server Clients and servers are separate logical
Entitles that work together over a network
To accomplish a task
lecture 1 slide 1

6. Client/server characteristics
Service
Shared resources
Asymmetrical protocols
Transparency of location
Mix and match
Message based exchanges
Encapsulation of services
Scalability
integrity
lecture 1 slide 2

7. Types of client/server architectures
File servers
Database servers
Transaction servers
Groupware servers
Object application servers
Web application servers
lecture 1 slide 3

8. Monolithic computing
Early computing was performed on a single processor
Makes use of a single cpu to execute one or more programs for each application
Ex: A uni-processor
lecture 1 slide 4

9. Distributed system
A distributed system is a collection of independent computers ,interconnected via a n/w.
Ex: WWW, ,ftp
lecture 2 slide 1

10. Historical trends Mainframe of 60’s Minicomputer Workstation Pc
Community culture
web
lecture 2 slide 2

11. Distributed computer advantages
The affordability of computers and availability of network access
Resource sharing
Scalability
Fault tolerance
lecture 2 slide 3

12. Distributed computer disadvantages
Multiple prints of failure
Security concerns
lecture 2 slide 4

13. Specific types of servers
App-servers
File servers
Mail servers
Terminal servers
lecture 2 slide 5

14. Servers can be
Stateless servers: do not keep any information b/w requests
Ex: http
Stateful servers : can remember information
Ex: apache tomcat
lecture 2 slide 5

15. Types of clients Fat client Thin clients Hybrid clients
lecture 3 slide 1

16. Skills required by client/server applications development
Transaction processing
Database design
Communications experience
Gui design
Internet server
Knowledge of distributed objects and component instructors
lecture 3 slide 2

17. ERP ERP vendors now offer client/server solutions for
Consumer packaged goods
Automotive
Sales force automotive
Online catalogs
Retail
Oil and gas
Supply chain management
Banking
E-commerce
lecture 3 slide 3

18. Comparison of 2-tier with 3-tier
Security :low
Performance :poor
Scale :poor
Application reuse :poor
Ease of development :high
Server to server infrastructure :no
Legacy application :no
Internet support :poor
System administrations :complex
lecture 3 slide 4

19. Comparison of 2-tier with 3-tier
Security :high
Performance :high
Scale :good
Application reuse :good
Ease of development :low
Server to server infrastructure :yes
Legacy application :yes
Internet support :good
System administrations :less complex
lecture 4 slide 1

20. Benefits of client/server programming
You can develop big applications in small steps
Applications can reuse components.
Clients can access data and functions easily and safely
Custom applications can incorporate off-the-shelf components
Component environments don’t get older – they only get better
lecture 4 slide 2

21. Benefits of client/server programming
Vendor independence as compared to the traditional mainframe computing. This includes application development methodologies, programming paradigms, products and architectures
Organization have changed from steep hierarchies to flattened hierarchies. Decisions making are carried out by many lower ranked managers across the organization rather than performed only by CEOs in the past.
lecture 4 slide 3

22. Benefits of client/server programming
Network management is replacing vertical management
Faster response and flexibility to changing environment of business world outside
The customer has a single point of contact for all business with the organization
The time required to complete the work will be minimized
lecture 4 slide 4

23. Benefits of client/server programming
Better sharing of critical database resources and other application software's among clients through the network.
Companies can cut costs on maintenance in employing Client- Server Computing since servers are usually cheaper than mainframe (1/10 of mainframe) and the performance of servers and mainframe are nearly identical.
Networked webs of small, powerful machines. If one machine goes down, the organization can still function properly.
lecture 5 slide 1

24. Benefits of client/server programming
Systems grow easily. It is easy to updated and modernize system, both hardware and software as the companies evolved and has new requirements.
Individual client operating environments. You can mix and match computer platforms to suit the needs of individual departments and users.
lecture 5 slide 2

25. Pitfalls of client/server computing
Dependability - when the server goes down, operations cease
Lack of mature tools - it is a relatively new technology and needed tools are lacking
e.g.. Automated client software distribution
Lack of scalability - network operating systems (e.g.. Novell Netware, Windows NT Server) are not very scalable.
Higher than anticipated costs
Can cause network congestion
What some call advantages, others call disadvantages
lecture 5 slide 3

26. Database servers
lecture 5 slide 4

27. File servers
lecture 5 slide 5