1 TCS Confidential

2 Objective : In this session we will be able to learn:  What is Cloud Computing?  Characteristics  Cloud Flavors  Cloud Deployment models  Opportunities and Challenges  Advantages  Disadvantages

3 TCS Confidential  Cloud computing is internet-based computing in which large groups of remote servers are networked to allow the centralized data storage, and online access to computer services or resources.  Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network.  Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources. Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users.

4 TCS Confidential  Common Characteristics:  Essential Characteristics: Massive Scale Homogeneity Virtualization Low Cost Software Resilient Computing Geographic Distribution Service Orientation Advanced Security Broad Network Access Resource PoolingMeasured Service Rapid Elasticity On Demand Self-Service

5 TCS Confidential  Cloud computing providers offer their services as: –Software as a Service (SaaS) –Platform as a Service (PaaS) –Infrastructure as a Service (IaaS)

6 TCS Confidential  SaaS is sometimes referred to as "on-demand software" and is usually priced on a pay-per-use basis.  In the business model using software as a service (SaaS), users are provided access to application software and databases.  Examples are online providers like Google’s gmail and Microsoft’s hotmail.

7 TCS Confidential  In the PaaS models, cloud providers deliver a computing platform, typically including operating system, programming language execution environment, database, and web server.  Platform as a service (PaaS) provides a computing platform and joins with software as a service (SaaS) and infrastructure as a service (IaaS), model of cloud computing.  Examples are Google’s Application Engine, Microsoft’s Azure.

8 TCS Confidential  In the most basic cloud-service model & according to the IETF (Internet Engineering Task Force), providers of IaaS offer computers – physical or (more often) virtual machines – and other resources.  Leading vendors that provide Infrastructure as a service are Amazon EC2, Amazon S3, Rackspace Cloud Servers.

9 TCS Confidential  Private Cloud  Community Cloud  Public Cloud  Hybrid Cloud

10 TCS Confidential  Private cloud is cloud infrastructure which is dedicated to a particular organization and not shared with other organizations.  Private clouds are more expensive and more secure when compared to public clouds.

11 TCS Confidential  A cloud is called a "public cloud" when the services are rendered over a network that is open for public use.  Public cloud services may be free or offered on a pay-per-usage model.  Generally, public cloud service providers like Amazon AWS, Microsoft and Google operate the infrastructure at their data center and access is generally via the Internet.

12 TCS Confidential  Organizations may host critical applications on private clouds and applications with relatively less security concerns on the public cloud.  The usage of both private and public clouds together is called “Hybrid Cloud.”  For example:- An organization may store sensitive client data in house on a private cloud application, but interconnect that application to a business intelligence application provided on a public cloud as a software service.

13 TCS Confidential  Community Cloud: Community cloud shares infrastructure between several organizations from a specific community with common concerns (security, compliance, jurisdiction, etc.).  Distributed Cloud: Cloud computing can also be provided by a distributed set of machines that are running at different locations, while still connected to a single network or hub service.  Inter Cloud: The Inter Cloud is an interconnected global "cloud of clouds“ and an extension of the Internet "network of networks" on which it is based.  Multi Cloud: Multi Cloud is the use of multiple cloud computing services in a single heterogeneous architecture to reduce reliance on single vendors, increase flexibility through choice

14 TCS Confidential  The use of the cloud provides a number of opportunities: –It enables services to be used without any understanding of their infrastructure. –Cloud computing works using economies of scale: It potentially lowers the outlay expense for start up companies, as they would no longer need to buy their own software or servers. Cost would be by on-demand pricing. Vendors and Service providers claim costs by establishing an ongoing revenue stream. –Data and services are stored remotely but accessible from “any where”.

15 TCS Confidential  In parallel there has been backslash against cloud computing: –Use of cloud computing means dependence on others and that could possibly limit flexibility and innovation: The others are likely become the biggest Internet companies like Google and IBM, who may monopolise the market. Some argue that this use of supercomputers is a return to the time of mainframe computing that the PC was a reaction against. –Security could prove to be a big issue: It is still unclear how safe out-sourced data is and when using these services ownership of data is not always clear. –There are also issues relating to policy and access: If your data is stored abroad whose policy do you adhere to? What happens if the remote server goes down? How will you then access files? There have been cases of users being locked out of accounts and losing access to data.

16 TCS Confidential  Lower computer costs  Improved performance  Reduced software costs  Instant software updates  Improved document format compatibility  Unlimited storage capacity  Increased data reliability  Universal document access  Latest version availability  Easier group collaboration  Device independence

17 TCS Confidential  Requires a constant Internet connection  Does not work well with low-speed connections  Features might be limited  Can be slow  Stored data might not be secure  Stored data can be lost  HPC Systems  General Concerns

18 TCS Confidential  Cloud computing is internet-based computing in which large groups of remote servers are networked to allow the centralized data storage.  Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand.  SaaS is sometimes referred to as "on-demand software" and is usually priced on a pay-per-use basis.  In the PaaS models, cloud providers deliver a computing platform, typically including operating system, programming language execution environment, database, and web server.  IaaS offer computers – physical or (more often) virtual machines – and other resources.  A cloud is called a "public cloud" when the services are rendered over a network that is open for public use.  Private clouds are more expensive and more secure when compared to public clouds.  The usage of both private and public clouds together is called “Hybrid Cloud.”

19 TCS Confidential  What is cloud Computing? What are the essential characteristics of Cloud?  What are the Cloud flavors?  List some differences between public cloud and private cloud?  What is an Inter cloud?  What are the advantages of Cloud?