Imagine yourself in the world where the users of the computer of todays Internet world dont have to run, install or store their application or data on their own computers, imagine the world where every piece of your information or data would reside on the Cloud (Internet).
As a metaphor for the Internet, "the cloud" is a familiar cliché, but when combined with "computing", the meaning gets bigger and fuzzier. Some analysts and vendors define cloud computing narrowly as an updated version of utility computing: basically virtual servers available over the Internet. Others go very broad, arguing anything you consume outside the firewall is "in the cloud", including conventional outsourcing.
Cloud computing comes into focus only when you think about what we always need: a way to increase capacity or add capabilities on the fly without investing in new infrastructure, training new personnel, or licensing new software. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends ICT's existing capabilities.
Cloud computing is at an early stage, with a motley crew of providers large and small delivering a slew of cloud-based services, from full-blown applications to storage services to spam filtering. Yes, utility-style infrastructure providers are part of the mix, but so are SaaS (software as a service) providers such as Salesforce.com. Fig. 1.1
Chapter 2
Cloud Computing - The Concept
"A concept is stronger than a fact."
2. Cloud computing- The Concept
Cloud computingDef1 is Internet ("cloud") based development and use of computer technology ("computing"). It is a style of computing in which dynamically scalable and often virtualized resources are provided as a service over the Internet. Users need not have knowledge of, expertise in, or control over the technology infrastructure "in the cloud" that supports them.
The concept incorporates infrastructure as a serviceDef2 (IaaS), platform as a serviceDef3 (PaaS) and software as a serviceDef4 (SaaS) as well as Web 2.0Def5 and other recent technology trends which have the common theme of reliance on the Internet for satisfying the computing needs of the users. Examples of SaaS vendors include Salesforce.com and Google Apps which provide common business applications online that are accessed from a web browser, while the software and data are stored on the servers.The term cloud is used as a metaphor for the Internet, based on how the Internet is depicted in computer network diagrams, and is an abstraction for the complex infrastructure it conceals.
Fig. 2.1
2.1 Comparison
Cloud computing is often confused with grid computing ("a form of distributed computing whereby a 'super and virtual computer' is composed of a cluster of networked, loosely-coupled computers, acting in concert to perform very large tasks"), utility computing (the "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility such as electricity") and autonomic computing ("computer systems capable of self-management").
Indeed many cloud computing deployments as of 2009 depend on grids, have autonomic characteristics and bill like utilities - but cloud computing can be seen as a natural next step from the grid-utility model. Some successful cloud architectures have little or no centralized infrastructure or billing systems whatsoever, including peer-to-peer networks like Bit Torrent and Skype and volunteer computing like
2.2 Implementation
The majority of cloud computing infrastructure as of 2009 consists of reliable services delivered through data centers and built on servers with different levels of virtualization technologies. The services are accessible anywhere that has access to networking infrastructure. The Cloud appears as a single point of access for all the computing needs of consumers. Commercial offerings need to meet the quality of service requirements of customers and typically offer service level agreements. Open standards are critical to the growth of cloud computing and open source software has provided the foundation for many cloud computing implementations.
2.3 Characteristics
As customers generally do not own the infrastructure, they merely access or rent, they can avoid capital expenditure and consume resources as a service, paying instead for what they use. Many cloud-computing offerings have adopted the utility computing model, which is analogous to how traditional utilities like electricity are consumed, while others are billed on a subscription basis. Sharing "perishable and intangible" computing power among multiple tenants can improve utilization rates, as servers are not left idle, which can reduce costs significantly while increasing the speed of application development. A side effect of this approach is that "computer capacity rises dramatically" as customers do not have to engineer for peak loads. Adoption has been enabled by "increased high-speed bandwidth" which makes it possible to receive the same response times from centralized infrastructure at other sites.
2.4 Economics
Cloud computing users can avoid capital expenditure (CapEx) on hardware, software and services, rather paying a provider only for what they use. Consumption is billed on a utility (e.g. resources consumed, like electricity) or subscription (e.g. time based, like a newspaper) basis with little or no upfront cost. Other benefits of this time sharing style approach are low barriers to entry, shared infrastructure and costs, low management overhead and immediate access to a broad range of applications. Users can generally terminate the contract at any time (thereby avoiding return on investment risk and uncertainty) and the services are often covered by service level agreements with financial penalties.
According to Nicholas Carr the strategic importance of information technology is diminishing as it becomes standardized and cheaper. He argues that the cloud computing paradigm shift is similar to the displacement of electricity generators by electricity grids early in the 20th century.
Fig. 2.2
2.5 Companies
Cloud computing infrastructure tech&solution provider:
3 Tera - AppLogic grid OS used as cloud computing platform by service providers and enterprises
Skytap - IaaS service optimized for QA, Training, Demo, and Ops Testing. Supports VMware, Xen hypervisors & Windows, Linux & Solaris OS guests.
Joyent - Cloud Infrastructure (Accelerators) and consulting for developers and enterprise.
Cloud computing infrastructure provider:
Amazon Web Services - Amazon EC2/S3 (Hardware-a-a-S & Cloud Storage)
GoGrid - instant, on-demand servers offering "control in the cloud". Deploy Windows/Linux servers via web-interface in minutes
Cloud computing Paas provider:
Force.com - Salesforce.com's application development platform (PaaS)
Google AppEngine - (PaaS)Now support python
Fig. 2.3
Chapter 3
Key Characteristics
"The distinguishing fact"
3. Key characteristics
3.1 Cost
Cost is greatly reduced and capital expenditure is converted to operational expenditure. This lowers barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and minimal or no IT skills are required for implementation.
3.2 Device and location independence
Device and location independence enable users to access systems using a web browser regardless of their location or what device they are using, e.g., PC, mobile. As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet the users can connect from anywhere.
3.3 Multi-tenancy
Multi-tenancy enables sharing of resources and costs among a large pool of users, allowing for:
3.3.1 Centralization of infrastructure in areas with lower costs (such as real estate, electricity, etc.)
3.3.2 Peak-load capacity increases (users need not engineer for highest possible load- levels)
3.3.3 Utilization and efficiency improvements for systems that are often only 10-20% utilized.
3.4 Reliability
Reliability improves through the use of multiple redundant sites, which makes it suitable for business continuity and disaster recovery. Nonetheless, most major cloud computing services have suffered outages and IT and business managers are able to do little when they are affected.
3.5 Scalability
Scalability via dynamic ("on-demand") provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads. Performance is monitored and consistent and loosely-coupled architectures are constructed using web services as the system interface.
3.6 Security
Securtiy typically improves due to centralization of data, increased security-focused resources, etc., but raises concerns about loss of control over certain sensitive data. Security is often as good as or better than traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford. Providers typically log accesses, but accessing the audit logs themselves can be difficult or impossible.
3.7 Sustainability
Sustainability comes about through improved resource utilization, more efficient systems, and carbon neutrality. Nonetheless, computers and associated infrastructure are major consumers of energy.
Chapter 4
Components of Cloud Architecture
"The least flexible component of any system is the user."
4. Components of Cloud Architecture
Cloud computing Components/Layers
Applications
Facebook · Google Apps · SalesForce · Microsoft Online
Client
Browser(Chrome) · Firefox · Cloud · Mobile (Android · iPhone) · Netbook (EeePC · MSI Wind) · Nettop (CherryPal · Zonbu)
Infrastructure
BitTorrent · EC2 · GoGrid · Sun Grid · 3tera
Platforms
App Engine · Azure · Mosso · SalesForce
Services
Alexa · FPS · MTurk · SQS
Storage
S3 · SimpleDB · SQL Services
Standards
Ajax · Atom · HTML 5 · REST
Fig. 4.1
4.1 Application
A cloud application leverages the Cloud in software architecture, often eliminating the need to install and run the application on the customer's own computer, thus alleviating the burden of software maintenance, ongoing operation, and support.
For example:
Peer-to-peer / volunteer computing (Bittorrent, BOINC Projects, Skype)
Web application (Facebook,Orkut)
Software as a service (Google Apps, SAP and Salesforce)
Software plus services (Microsoft Online Services)
Fig. 4.2
4.2 Client
A cloud client consists of computer hardware and/or computer software which relies on cloud computing for application delivery, or which is specifically designed for delivery of cloud services and which, in either case, is essentially useless without it.
For example:
Mobile (Android, iPhone, Windows Mobile)
Thin clientDef7 (CherryPal, Zonbu, gOS-based systems)
Thick clientDef8 / Web browser (Google Chrome, Mozilla Firefox)
4.3 Infrastructure
Cloud infrastructure, such as Infrastructure as a service, is the delivery of computer infrastructure, typically a platform virtualizationDef6 environment, as a service. For example:
Full Virtualization(GoGrid, Skytap)
Management(RightScale)
Compute(Amazon Elastic Compute Cloud)
Platform(Force.com)
Fig. 4.3
4.4 Platform
A cloud platform, such as Platform as a service, the delivery of a computing platform, and/or solution stack as a service, facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers.
For example:
Web application frameworks
Python Django (Google App Engine)
Ruby on Rails (Heroku)
.NET (Azure Services Platform)
Web hostingDef9 (Mosso)
Proprietary (Force.com)
4.5 Service
A cloud service includes "products, services and solutions that are delivered and consumed in real-time over the Internet". For example, Web Services ("software system[s] designed to support interoperable machine-to-machine interaction over a network") which may be accessed by other cloud computing components, software, e.g., Software plus service, or end users directly.
Specific examples include:
Identity (OAuth, OpenID)
Integration (Amazon Simple Queue Service)
Payments (Amazon Flexible Payments Service, Google Checkout, PayPal)
Mapping (Google Maps, Yahoo! Maps)
Search (Alexa, Google Custom Search, Yahoo! BOSS)
Others (Amazon Mechanical Turk)
4.6 Storage
Cloud storage involves the delivery of data storage as a service, including database-like services, often billed on a utility computing basis, e.g., per gigabyte per month. At the most rudimentary level, a cloud storage system just needs one data server connected to the Internet. A subscriber copies files to the server over the Internet, which then records the data. When a client wants to retrieve the data, he or she accesses the data server with a web-based interface, and the server then either sends the files back to the client or allows the client to access and manipulate the data itself.
For example:
Database (Amazon SimpleDB, Google App Engine's BigTable datastore)
Network attached storageDef10 (MobileMe iDisk, Nirvanix CloudNAS)
Synchronization (Live Mesh Live Desktop component, MobileMe push functions)
Web service (Amazon Simple Storage Service, Nirvanix SDN)
Fig. 4.4
Chapter 5
Cloud Architecture
"An important work of architecture will create polemics."
5. Architecture
Cloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, comprises hardware and software designed by a cloud architect who typically works for a cloud integrator. It typically involves multiple cloud components communicating with each other over application programming interfaces, usually web services. This closely resembles the UNIX philosophy of having multiple programs doing one thing well and working together over universal interfaces. Complexity is controlled and the resulting systems are more manageable than their monolithic counterparts.
At this point, working definition for cloud computing is two fold. From an engineering perspective the cloud is a computing architecture characterized by a large number of interconnected identical computing devices that can scale on demand and that communicate via an IP network. From a business perspective it is computing services that are scalable and billed on a usage basis. From a consumer's point of view this just doesn't matter. As long as the provider can deliver these services, how they do it is really immaterial. From the consumer's perspective, the architecture the vendor uses to deliver their services is only significant in terms of the cost reductions that the vendor realized through commodity hardware and software purchases and that they choose to pass along to the consumer. A second factor that may affect the consumer might be a limited selection of technologies that the vendor is willing or able to support because their support infrastructure would be designed to support a certain limited set of technologies. Another significant concern is vendor lock in, but this concern exists whether the vendor is using cloud architecture or not. In fact, those vendor who don't use cloud architectures to deliver services are probably more likely to impose vendor lock in, because the products they use will be proprietary and impose a vendor lock in that they will have little recourse but to pass along to their customers.
Cloud architecture extends to the client, where web browsers and/or software applications access cloud applications. Cloud storage architecture is loosely coupled, where metadata operations are centralized enabling the data nodes to scale into the hundreds, each independently delivering data to applications or user.
Fig. 5.1
Fig. 5.2
Chapter 6
Types of Clouds
6. Types of Clouds
Fig. 6.1
6.1 Public cloud
Public cloud or external cloud describes cloud computing in the traditional mainstream sense, whereby resources are dynamically provisioned on a fine-grained, self-service basis over the Internet, via web applications/web services, from an off-site third-party provider who shares resources and bills on a fine-grained utility computing basis.
An infrastructure spanning multiple administrative domains that is made available to the general public / businesses, without physical partitioning of resource allocations. (There is arguably only one public Cloud - hence the phrase "hosts it in The Cloud".)
6.2 Private cloud
Private cloud and internal cloud are neologisms that some vendors have recently used to describe offerings that emulate cloud computing on private networks. These products claim to "deliver some benefits of cloud computing without the pitfalls", capitalizing on data security, corporate governance, and reliability concerns.
While an analyst predicted in 2008 that private cloud networks would be the future of corporate IT, there is some uncertainty whether they are a reality even within the same firm. Analysts also claim that within five years a "huge percentage" of small and medium enterprises will get most of their computing resources from external cloud computing providers as they "will not have economies of scale to make it worth staying in the IT business" or be able to afford private clouds.
The term has also been used in the logical rather than physical sense, for example in reference to platform as service offerings, though such offerings including Microsoft's Azure Services Platform are not available for on-premises deployment.
Private Cloud enables:
Management of the datacenter fabric as a single pool of resources.
Delivery of scalable applications and workloads.
Focus on the management of the datacenter service and it's dependencies.
6.3 Hybrid cloud
A hybrid cloud environment consisting of multiple internal and/or external providers "will be typical for most enterprises".
A combination of public public and private compute utilities in order to allow "cloud bursting" for some requirements, or to allow a private compute utility owner to sell their spare capacity into The Cloud. A hybrid cloud is a cloud computing environment in which an organization provides and manages some resources in-house and has others provided externally. For example, an organization might use a public cloud service, such as Amazon's Elastic Compute Cloud (EC2) for general computing but store customer data within its own data centerDef11.
Chapter 7
Rolls of Cloud
7. Rolls of Cloud
7.1 Provider
A cloud computing provider or cloud computing service provider owns and operates live cloud computing systems to deliver service to third parties. The barrier to entry is also significantly higher with capital expenditure required and billing and management creates some overhead. Nonetheless, significant operational efficiency and agility advantages can be realized, even by small organizations, and server consolidation and virtualization rollouts are already well underway. Amazon.com was the first such provider, modernizing its data centers which, like most computer networks, were using as little as 10% of its capacity at any one time just to leave room for occasional spikes. This allowed small, fast-moving groups to add new features faster and easier, and they went on to open it up to outsiders as Amazon Web Services in 2002 on a utility computing basis.
7.2 User
A user is a consumer of cloud computing. The privacy of users in cloud computing has become of increasing concern. The rights of users are also an issue, which is being addressed via a community effort to create a bill of rights.
7.3 Vendor
A vendor sells products and services that facilitate the delivery, adoption and use of cloud computing. For example:
Computer hardware (Dell, HP, IBM, Sun Microsystems)
Storage (Sun Microsystems, EMC, IBM)
Infrastructure (Cisco Systems)
Computer software (3tera, Hadoop, IBM, RightScale)
Operating systems (Solaris, AIX, Linux including Red Hat)
Platform virtualization (Citrix, Microsoft, VMware, Sun xVM, IBM)
Chapter 8
Standards
8. Standards
Cloud standards, a number of existing, typically lightweight, open standards, have facilitated the growth of cloud computing, including:
Application
Communications (HTTP, XMPP)
Security (OAuth, OpenID, SSL/TLS)
SyndicationDef12 (Atom)
Client
Browsers (AJAX)
Offline (HTML 5)
Implementations
Virtualization (OVF)
Platform
Solution stacksDef13 (LAMP)
Service
Data (XML, JSON)
Web Services (REST)
Storage
Database(Amazon Simple DB, Google App Engine BigTable Datastore)
Network attached storage (MobileMe iDisk, Nirvanix CloudNAS)
Synchronization (Live Mesh Live Desktop component, MobileMe push functions)
Web service (Amazon Simple Storage Service, Nirvanix SDN)
Chapter 9
Case Study
9. Case Study
9.1 Amazon EC2
Fig 13.1
Amazon Elastic Compute Cloud (also known as "EC2") is a commercial web service that allows customers to rent computers on which to run their own computer applications. EC2 allows scalable deployment of applications by providing a web services interface through which a customer can create virtual machines, i.e. server instances, on which the customer can load any software of his choice. A customer can create, launch, and terminate server instances as needed, paying by the hour for active servers, hence the term "elastic". A customer can set up server instances in zones insulated from each other for most failure causes so that one may be a backup for the other and minimize down time. Amazon.com provides EC2 as one of several web services marketed under the blanket term Amazon Web Services (AWS).
History
Amazon announced a limited public beta of EC2 on August 25, 2006. Access to EC2 was granted on a first come first served basis. EC2 became generally available on October 23, 2008 along with support for Microsoft Windows Server.
Virtual machines
EC2 uses Xen virtualization. Each virtual machine, called an "instance", functions as a virtual private server in one of three sizes; small, large or extra large. Amazon.com sizes instances based on "EC2 Compute Units" - the equivalent CPU capacity of physical hardware. One EC2 Compute Unit equals 1.0-1.2 GHz 2007 Opteron or 2007 Xeon processor. The system offers the following instance types:
Small Instance
The small instance (default) equates to "a system with 1.7 GB of memory, 1 EC2 Compute Unit (1 virtual core with 1 EC2 Compute Unit), 160 GB of instance storage, 32-bit platform"
Large Instance
The large instance represents "a system with 7.5 GB of memory, 4 EC2 Compute Units (2 virtual cores with 2 EC2 Compute Units each), 850 GB of instance storage, 64-bit platform".
Extra Large Instance
The extra large instance offers the "equivalent of a system with 15 GB of memory, 8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units each), 1690 GB of instance storage, 64-bit platform."
High-CPU Instance
Instances of this family have proportionally more CPU resources than memory (RAM) and address compute-intensive applications.
High-CPU Medium Instance
Instances of this family have the following configuration:
1.7 GB of memory
5 EC2 Compute Units (2 virtual cores with 2.5 EC2 Compute Units each)
350 GB of instance storage
32-bit platform
I/O Performance: Moderate
High-CPU Extra Large Instance
Instances of this family have the following configuration:
7 GB of memory
20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each)
1690 GB of instance storage
64-bit platform
I/O Performance: High
Pricing
Amazon charges customers in two primary ways:
Hourly charge per virtual machine
Data transfer charge
The hourly virtual machine rate is fixed, based on the capacity and features of the virtual machine. Amazon advertising describes the pricing scheme as "you pay for resources you consume," but defines resources such that an idle virtual machine is consuming resources, as opposed to other pricing schemes where one would pay for basic resources such as CPU time.
Customers can easily start and stop virtual machines to control charges, with Amazon measuring with one hour granularity. Some are thus able to keep each virtual machine running near capacity and effectively pay only for CPU time actually used.
As of March 2009, Amazon's time charge is about $73/month for the smallest virtual machine without Windows and twelve times that for the largest one running Windows. The data transfer charge ranges from $.10 to $.17 per gigabyte, depending on the direction and monthly volume.Amazon does not have monthly minimums or account maintenance charges.
Operating systems
When it launched in August 2006, the EC2 service offered Linux and later Sun Microsystems' OpenSolaris and Solaris Express Community Edition. In October 2008, EC2 added the Windows Server 2003 operating system to the list of available operating systems.
Plans are in place for the Eucalyptus interface for the Amazon API to be packaged into the standard Ubuntu distribution.
Persistent Storage
Amazon.com provides persistent storage in the form of Elastic Block Storage (EBS). Users can set up and manage volumes of sizes from 1GB to 1TB. The servers can attach these instances of EBS to one server at a time in order to maintain data storage by the servers
9.2 Salesforce.com
Fig. 13.2
Salesforce.com (NYSE: CRM) is a vendor of Customer Relationship Management (CRM) solutions, which it delivers to businesses over the internet using the software as a service model
Origins
Salesforce.com was founded in 1999 by former Oracle executive Marc Benioff. In June 2004, the company went public on the New York Stock Exchange under the stock symbol CRM. Initial investors in salesforce.com were Marc Benioff, Larry Ellison, Halsey Minor, Magdalena Yesil and Igor Sill, Geneva Venture Partners.
Current status
Salesforce.com is headquartered in San Francisco, California, with regional headquarters in Dublin (covering Europe, Middle East, and Africa), Singapore (covering Asia Pacific less Japan), and Tokyo (covering Japan). Other major offices are in Toronto, New York, London, Sydney, and San Mateo, California. Salesforce.com has its services translated into 15 different languages and currently has 43,600 customers and over 1,000,000 subscribers. In 2008, Salesforce.com ranked 43rd on the list of largest software companies in the world.
Following the Federal takeover of Freddie Mac and Fannie Mae in September 2008, the S&P 500 removed the two mortgage giants after Wednesday, September 10, 2008, and added Fastenal and Salesforce.com to the index, effective after Friday, September 12, 2008
Products and Services
Customer Relationship Management
Salesforce.com's CRM solution is broken down into several applications: Sales, Service & Support, Partner Relationship Management, Marketing, Content, Ideas and Analytics.
Force.com Platform
Salesforce.com's Platform-as-a-Service product is known as the Force.com Platform. The platform allows external developers to create add-on applications that integrate into the main Salesforce application and are hosted on salesforce.com's infrastructure.
These applications are built using Apex (a proprietary Java-like programming language for the Force.com Platform) and Visualforce (an XML-like syntax for building user interfaces in HTML, AJAX or Flex).
AppExchange
Launched in 2005, AppExchange is a directory of applications built for Salesforce by third-party developers which users can purchase and add to their Salesforce environment. As of September 2008, there are over 800 applications available from over 450 ISVs.
Customization
Salesforce users can customize their CRM application. In the system, there are tabs such as "Contacts", "Reports", and "Accounts". Each tab contains associated information. For example, "Contacts" has fields like First Name, Last Name, Email, etc.
Customization can be done on each tab, by adding user-defined custom fields.
Customization can also be done at the "platform" level by adding customized applications to a Salesforce.com instance that is adding sets of customized / novel tabs for specific vertical- or function-level (Finance, Human Resources, etc) features.
Web Services
In addition to the web interface, Salesforce offers a Web Services API that enables integration with other systems
Chapter 10
Conclusion
10. Conclusion
Cloud Computing is a vast topic and the above report does not give a high level introduction to it. It is certainly not possible in the limited space of a report to do justice to these technologies. What is in store for this technology in the near future? Well, Cloud Computing is leading the industry's endeavor to bank on this revolutionary technology.
Cloud Computing Brings Possibilities……..
Increases business responsiveness
Accelerates creation of new services via rapid prototyping capabilities
Reduces acquisition complexity via service oriented approach
Uses IT resources efficiently via sharing and higher system utilization
Reduces energy consumption
Handles new and emerging workloads
Scales to extreme workloads quickly and easily
Simplifies IT management
Platform for collaboration and innovation
Cultivates skills for next generation workforce
Today, with such cloud-based interconnection seldom in evidence, cloud computing might be more accurately described as "sky computing," with many isolated clouds of services which IT customers must plug into individually. On the other hand, as virtualization and SOA permeate the enterprise, the idea of loosely coupled services running on an agile, scalable infrastructure should eventually make every enterprise a node in the cloud. It's a long-running trend with a far-out horizon. But among big metatrends, cloud computing is the hardest one to argue with in the long term.
Cloud Computing is a technology which took the software and business world by storm. The much deserved hype over it will continue for years to come.
Appendix A
Definitions
Appendix A
Definitions
Def1- (Cloud Computing)
Cloud computing is a way of computing, via the Internet, that broadly shares computer resources instead of using software or storage on a local PC.
Def2- (Iaas- Infrastructure as a Service)
Cloud infrastructure services or "Infrastructure as a Service (IaaS)" delivers computer infrastructure, typically a platform virtualization environment, as a service.
Def3- (Paas- Platform as a Service)
Cloud platform services or "Platform as a Service (PaaS)" deliver a computing platform and/or solution stack as a service, often consuming cloud infrastructure and sustaining cloud applications.
Def4- (Saas - Software as a Service)
Cloud application services or "Software as a Service (SaaS)" deliver software as a service over the Internet, eliminating the need to install and run the application on the customer's own computers and simplifying maintenance and support.
Def5- (Web 2.0)
The term "Web 2.0" (2004-present) is commonly associated with web applications that facilitate interactive information sharing, interoperability, user-centered design,[1] and collaboration on the World Wide Web.
Def6 - (Platform Virtualization)
In computing, platform virtualization is a term that refers to the abstraction of computer resources. Virtualization hides the physical characteristics of computing resources from their users, be they applications, or end users. The term has been widely used since the 1960s.
Def7 - (Thin Client)
A thin client (sometimes also called a lean or slim client) is a computer or a computer program which depends heavily on some other computer (its server) to fulfill its traditional computational roles.
Def8 - (Thick Client)
A fat client or rich client is a computer (client) in client-server architecture networks which typically provides rich functionality independently of the central server.
Def9 - (Web Hosting)
A web hosting service is a type of Internet hosting service that allows individuals and organizations to make their own website accessible via the World Wide Web.
Def10- (NAS- Network-attached storage)
Network-attached storage (NAS) is file-level computer data storage connected to a computer network providing data access to heterogeneous network clients.
Def11- (Data Center)
A data center or datacenter, also called a server farm, is a facility used to house computer systems and associated components, such as telecommunications and storage systems.
Def12- (Web Syndication)
Web syndication is a form of syndication in which website material is made available to multiple other sites.
Def13- (Solution Stack)
In computing, a solution stack is a set of software subsystems or components needed to deliver a fully functional solution, e.g. a product or service.
Appendix B
IEEE Paper
"CCOA: Cloud Computing Open Architecture"
