Introduction to cloud computing, its features, characteristics and challenges. And also the services provided by cloud i.e SaaS, Paas and IaaS.

1. CHAPTER 1:
INTRODUCTION TO CLOUD
COMPUTING
Prepared by: Adarsha Dhakal

2. “CLOUD IS JUST SOMEONE ELSE’S
COMPUTER”

3. CLOUD
• Just a big building filled with computers (servers)
• Servers are just computer that provides services on behalf of clients
• Big building = Data centers
• Data centers = Collection of many servers which performs numerous
tasks such as running applications, storing data, data processing, web
hosting which are networked together
• Cloud providers are companies who provides these cloud and their
purpose is to sell their computers as a service

4. CLOUD COMPUTING
• Network based utility computing that takes place over the Internet
• Provides services like data storage, servers, databases, networking, and
software.
• Provides on demand services, that are always on, anywhere, anytime and any
place (ubiquitous)
• Pay for use and as needed i.e scalable
• Services are available to general public, enterprises, corporations and
businesses markets
• Hides the complexity and details of the underlying infrastructure from users
and applications by providing very simple graphical interface or API
(Applications Programming Interface).

6. BEFORE CLOUD!
• Organizations had to build and maintain their own IT infrastructure to
support their business operations. This included investing in servers,
storage devices, networking equipment, and other hardware and
software components to support their applications and data. (On-
premise)
• Very costly
• Had to predict requirements
• Requires intelligent manpower
• Wastage of Resources

7. EVOLUTION
• Distributed Computing (1950)
• Mainframe Computing (1951)
• Cluster Computing (1980)
• Grid Computing (1990)
• Virtualization (1960-1970)
• Web 2.0 (2004)
• Service Orientation
• Utility Computing
• Cloud Computing

8. MAJOR CLOUD PROVIDERS
• Amazon Web services (AWS)
• Microsoft Azure
• Alibaba
• IBM

9. WHY CLOUD?
• Cost Effective
• Reliability
• Scalability
• Fault tolerant

10. FEATURES
• Scalable
• Resource-Pooling (multi-tenancy)
• On-Demand Self Service
• Metered by use
• Elasticity
• Customization

11. SERVICE MODEL/ CLOUD REFERENCE
MODEL
SaaS (End Users) : Consume
PaaS (Application Developers) : Build
IaaS
(Network Architects)
Host

12. SOFTWARE AS A SERVICE
• Software that is accessed via a web browser
• Generally paid on subscription basis
• No need to buy license purchase, maintance headache and installation
• No hardware implementation from customer’s side
• SaaS vendor manage and run the application with utmost security,
performance and reliability
• Highly automated business process
• Designed to run thousands of different customers on a single code
• Applications are hosted in ”the cloud”
• Examples: Google, Gmail, Netflix, Dropbox etc

13. SOFTWARE AS A SERVICE

14. ADVANTAGES
• No additional hardware costs
• No initial setup costs
• Pay for what you use
• Usage is scalable
• Updates are automated
• Cross device compatibility
• Accessible from any location

15. DRAWBACKS
• Security and confidentiality
• Risk of data loss
• Dependence on high speed internet
• Low predictability of cost
• Not all applications have SaaS versions yet
• In many cases SaaS versions may not be as powerful as non SaaS ones (
SaaS versions are stripped down versions of powerful non-SaaS product
)

16. PLATFORM AS A SERVICE
• Basically a platform (could be tools, software, middleware etc) that sits
on Infrastructure and is used for coding and deploying the applications.
• Provides a platform and environment to allow developers to build
applications and services over the internet.
• Includes application design, development, deployment, testing and
hosting
• Software developers, web developers and businesses can benefit from
PaaS
• Examples: Heroku, IBM cloud, AWS elastic beanstalk etc

17. ADVANTAGES
• Simplified Deployment
• Prebuilt Business Functionality
• Instant community
• Pay per use model
• Scalability
• Lower Risk

18. DRAWBACKS
• Vendor lock-in
• Data Privacy
• Integration with the rest of the systems and applications

19. INFRASTRUCTURE AS A SERVICE
• Commonly known as hardware as a service
• Organization outsources the equipment used to support operations,
including storage, hardware, servers and networking components
• Service provider owns the equipment and is responsible for housing,
running and maintaining it
• Client typically pays on a per-use basics
• Example: AWS EC2, Microsoft Azure, Google cloud, Digital Ocean etc.

20. ADVANTAGES
• Improved cash flow
• Support og uncertain provision planning
• Transparent metering and self-service management
• Dynamic Scaling

21. DRAWBACKS
• Security
• Compliance
• Outages

23. CHALLENGES OF CLOUD COMPUTING
• Security, Privacy and Trust : Data Leakage
• Availability, Fault-Tolerance and Disaster Recovery
• Vendor lock-in
• Insecure Interfaces
• Lack of visibility
• Resource Management and Energy Efficiency

24. CLOUD SERVICE REQUIREMENTS
• Compatibility with Heterogenous System
• Service Management
• Reliability Availability and Security
• Integration
• Disaster Recovery
• Control

25. THE END