Cloud Computing. Concepts, Technology and Architecture TUDOR MARIUS COSMIN

Transcription

1 Cloud Computing Concepts, Technology and Architecture TUDOR MARIUS COSMIN

2 Instructor Contact Information

3 Instructor Background Information Storage : Chief Delivery Officer for Infrastructure Solutions & Cloud Business Unit Role@MCloud 1 Leaded the delivery team from Star Storage Background IT and Business Management Business Process Management Project Management IT Security Accredited Tier Specialist for Data Centers Operations (Uptime Institute) Cloud Computing Certified Professional

4 Ground Rules There are not any! as long as you keep your mobiles on mute and laptop/tablet closed Ask questions, comment and challenge at anytime! I don t have all the answers, however might be able to get it later. Understand the time limitation -Rome was not built in a day

5 Instructor Contact

6 Timetable Session 1-05 March: Session 1-10 : 00 AM 11:20 AM Coffee break 11:20 AM 11:40 AM Session 2 11:40 AM 13:00 PM

7 Session 1 Overview A Brief History of Cloud Computing Fundamental Terminology and Concepts Characteristics of a cloud Roles and Boundaries Cloud Delivery Models Cloud Deployment Models Benefits of Cloud Computing Challenges of Cloud Computing Business Cost Metrics Service Level Agreements (SLAs) The world has chaged!

8 What is the CLOUD

9 When asked what the cloud is, a majority respond it s either an actual cloud, the sky, or something related to wheather Citrix Cloud Survey Guide

10 Cloud Computing Defined Cloud computing is a specialized form of distributed computing that introduces utilization models for remotely provisioning scalable and measured IT resources.

11 Cloud Defined A cloud is a distinct and remote IT environment designed for the purpose of remotely provisioning scalable and measured IT resources.

12 A Brief History of Cloud Computing

13 Overview The idea of computing in a CLOUD traces back to the origins of utility computing a concept published in 1961 by scientist John McCarty: If computers of the kind I have advocated become the computers of the future, then computing may someday be organized as a public utility just as the telephone system is a public utility. The computer utility could become the basis of a new and important industry. In 1969, Leonard Kleinrock, a chief scientist of the Advanced Research Projects Agency Network or ARPANET, stated: As of now, computer networks are still in their infancy, but as they grow up and become sophisticated, we will probably see the spread of computer utilities.

14 Overview Mid-1990s, various forms of Internet-based computer utilities: Search Engines: Yahoo!, Google Services: Hotmail, Gmail Social Media: My Space, Facebook, YouTube, Twitter, Linkedin Term Network Cloud or Cloud was introduced in early 1990s in networking industry In 2002, Amazon.com launched the Amazon Web Services (AWS) platform, a suite of enterprise-oriented services that provide remotely provisioned storage, computing resources, and business functionality In 2006 the term cloud computing emerged in the commercial arena. Amazon launched its Elastic Compute Cloud (EC2) services that enabled organizations to lease computing capacity and processing power to run their enterprise applications Google Apps also began providing browser-based enterprise applications in the same year, and three years later, the Google App Engine became another historic milestone.

15 Overview Cloud computing emerged from a combination of business drivers and technology innovations. Business drivers: Capacity Planning Cost reduction and Operating Overhead Organizational Agility Technology Innovations: Grid Computing Technology Clustering Technology Virtualization Technology

16 Business Drivers: Capacity Planning Capacity planning is an unavoidable responsibility for most IT enterprises, requiring that future demands on IT infrastructure be planned for and accommodated. Capacity planning can be very challenging because it can require estimating usage load fluctuations. There is a constant need to balance peak usage requirements without unnecessarily over-spending on IT infrastructure. To accommodate maximum usage loads may require too high of an investment. To moderate the investment may result in lost transactions and other usage limitations due to lower usage thresholds.

17 Business Drivers: Capacity Planning Different capacity planning strategies exist : Lead Strategy adding capacity to an IT resource in anticipation of demand Lag Strategy adding capacity when the IT resource reaches his full capacity Match Strategy adding IT resource capacity in small increments, as demand increases

18 Business Drivers: Cost Reduction and Operating Overhead Two costs need to be accounted for: the cost of acquiring new infrastructure The cost of its going ownership (TCO) Common forms of infrastructure-related operating overhead include the following: technical personnel required to keep the environment operational upgrades and patches that introduce additional testing and deployment cycles utility bills and capital expense investments for power and cooling security and access control measures that need to be maintained and enforced to protect infrastructure resources administrative and accounts staff that may be required to keep track of licenses and support arrangements

19 Business Drivers: Organization Agility Organizational agility represents the responsiveness of an organization in the face of business chance. so even elephants can walk on a tightrope

20 Technology Innovations: Grid Computing Grid computing emerged in the 90 s to introduce the concept of computing as a networked utility. A computing grid provides a platform in which computing resources are organized into one or more logical pools. With a grid you could plug into a pool of shared computing power the same way you would plug an appliance into a shared power grid This concept led to the notion of pay-as-you-go computing and further formed the basis of elasticity both of witch established fundamental characteristics of a cloud

21 Technology Innovations: Web/Clustering Architectures Because Web Applications were commonly made available to a wide public, they often became demand-driven and tended to be spiky in their usage loads. The back-end technology architectures that evolved in support of Webbased applications therefore introduced the need for: Load balancing Server farms Clustered servers Clustered databases

22 Technology Innovations: Virtualization Technology Virtualization is an established technology that has enabled hardware owners to repeatedly leverage physical servers for wide, concurrent usage. Virtualization further helped realize the notion of server elasticity by allowing one physical server to host a variable number of virtual servers. Virtualization is a key technology in modern cloud computing.

23 Fundamental Terminology and Concepts

24 Overview Before we can discuss the details of cloud computing, we need to first establish some fundamentals terms and concepts : IT Resource Virtualization Scaling Cloud On-Premise Service Cloud Service Service Agent

25 IT Resource An IT resource is a physical or virtual IT-related artifact (software or hardware). The following are common types of IT resources: physical server software program storage device virtual server service network device

26 Virtualization Virtualization allows physical IT resources to provide multiple virtual images of themselves so that their underlying processing capabilities can be shared individually by multiple consumers. The owner of the physical IT resource maintains centralized administrative control and intentionally hides implementation details fro consumers of the virtual IT resources. This abstraction of the physical IT resource allows consumers to use the provided virtual IT resources without any required knowledge of how the underlying physical IT resource exists or operates. As consumer usage demands fluctuate, the owner of the physical IT resource can scale it accordingly.

27 Virtualization For example, a physical computer will often contain a single installation of an operating system that can be used by a single consumer. Through virtualization, the same computer can provide multiple images of the same operating system installation that can be independently used by multiple consumers. The owner of the physical computer can retain administrative control of the computer hardware and the base operation system environment. Consumers of the virtual operating system images can independently configure and control their respective virtual environments, but are not given access to (nor require access to) the underlying physical environment.

28 Virtualization Virtualization is an established area of technology that emerged long before cloud computing. Within cloud environments, virtualization technology is primarily utilized to replicate multiple virtual images of the same physical server for remote access by consumers. A virtual server is a form of virtualization software that emulates a physical computer (a physical server). Each physical server can host multiple virtual servers. To a cloud consumer, a virtual server appears as an independent physical server.

29 Scaling Scaling, from an IT resource perspective, represents the ability of the IT resource to gracefully handle increased or decreased usage demands. The following are scaling related terms used in these courses: horizontal scaling scale out scale in vertical scaling scale up scale down

30 Scaling (Horizontal) Horizontal scaling refers to the allocation or releasing of resources of the same type. The horizontal allocation of resources is referred to as scaling out and the horizontal releasing of resources is referred to as scaling in. Horizontal scaling is a common form of scaling within cloud environments.

31 Scaling (Vertical) Vertical scaling occurs when an existing resource is replaced by another. The replacing of an IT resource with another that has a higher capacity is referred to as scaling up and the replacing an IT resource with another that has a lower capacity is referred to as scaling down. Vertical scaling is less common in cloud environments due to the downtime required while the replacement is taking place.

32 Scaling A comparison of horizontal and vertical scaling :

33 Cloud A cloud is a distinct and remote IT environment designed for the purpose of remotely provisioning scalable and measured IT resources. IT resources are provided by a cloud for consumers to access remotely, from outside the cloud perimeter. Consumers may or may not know the exact physical location of the IT resources provided by a cloud. Although a cloud will commonly be based on Web protocols and technologies, it is not necessary for a cloud to be Web-based. A cloud can exist with the use of any remote access protocols that allow for access to its IT resources.

34 Cloud Not every IT resource that resides inside a cloud needs to be made directly available to consumers. A cloud-based IT resource can be remotely accessed or it can support the remote access of other cloud-based IT resources. When an IT resource is made available to external consumers, it is accessible as a cloud service (as explained in the upcoming Cloud Service section).

35 Cloud Example A cloud hosting eight IT resources: three virtual servers, two cloud services, and three cloud storage devices.

36 On-Premise The term on-premise (or on-premises ) is used to qualify an IT resource that is not remotely accessible via a cloud, but instead resides within an internal IT enterprise environment. It is important to note that very often cloud-based IT resources are invoked by or communicate with on-premise IT resources. For example, an IT resource may be moved from an on-premise environment to a cloud, or vice versa.

37 On-Premise to Cloud

38 Service From an implementation perspective, a service is a software program that can be remotely invoked via a published technical interface (or API) referred to as a service contract. When a software program invokes and interacts with a service, it is labeled as a service consumer. Services acting as service consumers can invoke other services. When two or more services participate to complete a given task, the services from a service composition. A service can reside on-premise or in a cloud. In the latter case, it is further qualified as a cloud service (as explained in the following Cloud Service section).

39 Cloud Service The term service within the context of cloud computing is very broad. From a cloud computing perspective, any remotely accessible IT resource is classified as a service. A cloud service can therefore be considered an IT resource made remotely accessible via a cloud. Note that even though a cloud service exists as an IT resource, it may further provide access to other cloud-based IT resources. Note that a cloud service can exist as a software program that acts as an endpoint or access point to a larger application, platform or environment. From a consumer perspective, the larger application, platform or environment itself (and in its entirety) may be considered the service.

40 Cloud Service A cloud service can exist as: A traditional service (such as a Web service or a REST service) accessed via a published contract and messaging. A software program remotely accessed via other means (such as communicating with a software program on a server using a proprietary protocol)

41 Service Agent A service agent is an event-driven program capable of transparently intercepting and processing messages sent to or from services. Depending on the development platform you are working with, service agents may be called filters, listeners, interceptors, handlers, etc. Most modern runtime environments (and operating systems) provide a set of system service agents, but service agents can also be customdeveloped. Service agents do not have a technical interface (or service contract) and are therefore not explicitly invoked.

42 Service Agent Service agents are depicted using the rectangular block symbol. Common functions performed by service agents include routing, logging, validation, and security related processing. Service agents are important to cloud computing, especially for providing runtime monitoring and load balancing functions.

43 Characteristics of a Cloud

44 Overview Let s revisit the definition of cloud computing: Cloud computing is a specialized form of distributed computing that introduces utilization models for remotely provisioning scalable and measured IT resources. Let s revisit the definition of a cloud: A cloud is a distinct and remote IT environment designed for the purpose of remotely provisioning scalable and measured IT resources. In order to remotely provision scalable and measured IT resources in an effective manner, an IT environment requires a specific set of characteristics. These characteristics need to exist to a meaningful extent for the IT environment to be considered an effective cloud.

45 Cloud Characteristics This section is dedicated to individually describing the following six cloud characteristics : On-Demand Usage Ubiquitous Access Multitenancy Elasticity Measured Usage Resiliency

46 On-Demand Usage A cloud consumer can unilaterally access cloud-based IT resources giving the cloud consumer the freedom to self-provision these IT resources. Once configured, usage of the self-provisioned IT resources can be automated, requiring no further human involvement by the cloud consumer or cloud provider. This results in an on-demand usage environment.

47 Ubiquitous Access Ubiquitous access represents the ability for a cloud service to be widely accessible. Establishing ubiquitous access for a cloud service can require support for a range of transport protocols, interfaces and security technologies. To enable this level of access generally requires that the cloud service be tailored to the particular needs of different cloud service consumers.

48 Multitenancy (and Resource Pooling) Multitenancy is a characteristic of a software program that enables an instance of the program to serve different consumers (tenants), each of which is isolated from the other. A cloud provider pools its IT resources to serve multiple cloud service consumers by using the multitenancy model. Cloud-based multitenancy models frequently rely on the use of virtualization technologies. Through the use of multitenancy technology, IT resources can be dynamically assigned and reassigned, according to cloud service consumer demands.

49 The figure on the left is an example of single tenancy in that each cloud service consumer is provided a separate underlying IT resource instance (in this case, a storage device). The figure on the right illustrates multitenancy, whereby a single instance of an IT resource is provided to both cloud service consumers, each likely unaware that the IT resource is being shared.

50 Elasticity Elasticity is the automated ability of a cloud to gracefully and transparently scale IT resources, as required in response to runtime conditions or as predetermined by the cloud consumer or cloud provider. Elasticity is often considered a core justification for the adoption of cloud computing, primarily due to the fact that it is closely associated with the Reduced Investment and Proportional Costs benefit. Cloud providers with the vast resources can offer the greates range of elasticity.

51 Elasticity A sample workflow depicting elastic resource allocation.

52 Measured Usage Measured usage represents the ability of a cloud platform to keep track of the usage of its IT resources by cloud consumers. Based on what is measured, the cloud consumer is charged only for the IT resources actually used and/ or for the timeframe where access to the IT resources was required. Measured usage is not limited to tracking statistics for billing purposes. It also encompasses the general monitoring of IT resources and related usage reporting (to both cloud provider and cloud consumers).

53 Measured Usage A typical application of measured usage within a cloud is the monitoring and collection of runtime data by the cloud provider to be used for cloud consumer billing purposes, as demonstrated here.

54 Resiliency Resilient computing is a form of failover that distributes redundant implementations of IT resources across physical locations. IT resources can be pre-configured so that if one becomes deficient, processing is automatically handed over to another redundant IT resource. Within cloud computing, resiliency can refer to redundant IT resources within the same cloud (but in different physical locations) or across multiple clouds. Cloud consumers can increase the reliability and availability of cloudbased IT resources.

55 Resiliency For example, Cloud A provides Cloud Service A as part of a failover system that encompasses a redundant implementation of Cloud Service A on Cloud B. If Cloud Service A on Cloud A fails, then Cloud Service A on Cloud B is automatically provisioned transparently to Cloud Service Consumer A. Each cloud has a specific level of reliability and availability that it guarantees for Cloud Service A. By spanning the failover system across both clouds, the overall reliability and availability will be higher than the maximum reliability and availability of either cloud.

56 Roles and Boundaries

57 Overview Roles: Service Consumer Cloud Service Consumer Cloud Provider Cloud Consumer Cloud Resource Administrator Cloud Service Owner Boundaries: Organizational Boundary Trust Boundary

58 Service Consumer As described earlier in the Fundamental Terms & Concepts section, when a software program accesses a service it is labeled as a service consumer. A service consume is therefore a temporary runtime role assumed by a software program. A service itself may assume the role of a service consumer when it invokes and interacts with another service (as part of a service composition). To distinguish between service consumers that access on-premise and cloud-based services, those that access cloud services are further qualified as cloud service consumers (as explained next).

59 Cloud Service Consumer The cloud service consumer is a temporary runtime role assumed by a software program when it accessed a cloud service. The following are common types of cloud service consumers: software programs and services capable of remotely accessing cloud services with published service contracts (such as Web services) workstations, laptops and mobile devices running software capable of remotely accessing other IT resources positioned as cloud services (such as virtual servers)

60 Cloud Service Consumer The cloud service consumer role is assumed when:

61 Cloud Provider A cloud provider is the organization that owns (provides) a cloud. One cloud provider may own multiple clouds. When relevant, diagrams in these courses indicate the cloud providers of depicted clouds. When a cloud is not further labeled with a cloud provider, it is still implied that the cloud has a cloud provider.

62 Cloud Consumer A cloud consumer is an organization or a human that uses a cloud service consumer to access a cloud service. The diagrams in these courses do not often explicitly label symbols as cloud consumers. Instead, it is generally implied that organizations or humans shown remotely accessing cloud-based IT resources are considered cloud consumers.

63 Cloud Consumer In this example, Organization A is the cloud consumer In this example, the illustrated human is the cloud consumer

64 Cloud Service Owner A cloud service owner is the person or organization that legally owns a cloud service. The cloud service owner can be either the cloud consumer or the cloud provider of the cloud within which the cloud service resides. For example, if Cloud X hosts Cloud Service A then either the cloud consumer of Cloud X or the cloud provider of Cloud X can be the Cloud Service Owner of Cloud Service A. (See the upcoming diagrams).

65 Cloud Service Owner A cloud consumer can be a cloud service owner when it has deployed its own service in a cloud. A common example of this is when the cloud consumer uses a PaaS offering to develop and deploy its own cloud service (as explained in the upcoming Cloud Delivery models section).

66 Cloud Service Owner A cloud provider can be a cloud service owner when it deploys its own service in a cloud (typically for use by other cloud consumer) A common example of this is when the cloud providers make services commercially available as SaaS offerings (as explained in the upcoming Cloud Delivery models section).

67 Cloud Resource Administrator A cloud resource administrator is the person or organization responsible for administering a cloud-based IT resource (including cloud services). The cloud resource administrator can be (or belong to) the cloud consumer or cloud provider of the cloud within which the cloud service resides. Alternatively, it can be (or belong to) a third-party organization contracted to administer the cloud-based IT resource. For example, a cloud service owner could contract a cloud resource administrator to administer a cloud service.

68 Cloud Resource Administrator A cloud resource administrator can be with a cloud consumer organization and can administer remotely accessible IT resources that belong to the cloud consumer.

69 Cloud Resource Administrator A cloud resource administrator can be with a cloud provider organization for which it can administer IT resources (internally and externally available) belonging to the cloud provider.

70 Cloud Resource Administrator The reason we don t call the cloud resource administrator a cloud service administrator, is because this person or organization may be responsible for administering cloud-based IT resources that don t exist as cloud services. For example, if the cloud resource administrator belongs to (or is contracted by) the cloud provider, IT resources not made remotely accessible may be administered by this role (and these types of IT resources are not classified as cloud services).

71 In this scenario, the cloud provider s cloud resource administrator accesses an internal IT resource (the physical server) that hosts externally accessible IT resources (the virtual server and the cloud service) available to the cloud consumer.

72 Cloud Resource Administrator Note that the cloud resource administrator is a role assumed by a human (or a group of humans). It is not a role assumed by a software program. In diagrams, when we show the workstation symbol remotely accessing an IT resource (such as the virtual server in the diagram to the right), we refer to this as the cloud resource administrator. However, it is implied that the workstation being used by the human to perform the administration task is using a software program that technically is acting as a cloud service consumer.

73 Roles Summary Runtime roles assumed by software programs: service consumer (when a software program accesses an on-premise service) cloud service consumer (when a software program accesses a cloud service) Roles assumed by people/ organizations: cloud consumer (when a person/ organization uses IT resources provided by a cloud) cloud provider (the person / organization that owns/ provides a cloud) cloud resource administrator (the person/ organization responsible for administering a cloud-based IT resource)

74 Organizational Boundary and Trust Boundary An organizational boundary represents the physical perimeter that surrounds a set of IT resources owned by a specific organization. This means that an organizational boundary does not represent the boundary of an actual organization (only a set of organizational IT assets represented by IT resources). Organizational boundaries are generally used to indicate regions or environments that are under the control of the organization. Incorporating cloud computing into an IT enterprise can require that IT resources be placed outside of an organizational boundary. This can result in a loss of control of an organization s IT resources.

75 Organizational Boundary and Trust Boundary An organization acting as a cloud consumer has its own organizational boundary. A cloud provided by a cloud provider will have its own organizational boundary.

76 Organizational Boundary and Trust Boundary A trust boundary establishes a logical perimeter wherein IT resources are trusted from a security perspective. The IT enterprise within an organization can establish an internal trust boundary that encompasses its own IT resources.

77 Organizational Boundary and Trust Boundary Cloud-based IT resources that are used by a cloud consumer reside outside of the cloud consumer s organizational boundary. To use the IT resources, the cloud consumer will generally need to trust them. As a result, the cloud consumer s trust boundary is expanded beyond its organizational boundary to encompass the cloud.

78 Cloud Delivery Models

79 Overview A cloud delivery model represents a specific combination of IT resources offered by a cloud provider. Depending on the types of IT resources required by a cloud consumer, three common delivery models are used: Infrastructure-as-a-Service (IaaS) Platform-as-a-Service (PaaS) Software-as-a-Service (SaaS) Variations of these delivery models can also exist. Note that a cloud delivery model is also referred to as a cloud service delivery model because each model is classified as a different type of cloud service offering.

80 Infrastructure-as-a-Service (IaaS) The IaaS delivery model provides a self-contained IT environment comprised of infrastructure-centric IT resources. This environment can include hardware, network, connectivity, operating systems, and other raw IT resources. In contrast to traditional hosting or outsourcing IT environments, with IaaS, IT resources are typically virtualized and packaged into bundles that simplify up-front runtime scaling and customization of the infrastructure.

81 Infrastructure-as-a-Service (IaaS) Cloud consumers are provided with a range of contractual guarantees by the cloud provider, pertaining to characteristics such as capacity, performance, availability, etc.

82 Infrastructure-as-a-Service (IaaS) The IT resources provided by IaaS are generally raw and not preconfigured, placing the operational responsibility upon the cloud consumer. The IaaS delivery model is therefore used by cloud consumers that require a high level of control over the cloud-based environment they intend to create. Sometimes cloud providers will contract IaaS offerings from other cloud providers in order to scale their own cloud environments. The types and brands of the IT resources provided by IaaS products offered by different cloud providers can vary.

83 Platform-as-a-Service (PaaS) The PaaS delivery model provides a pre-defined cloud environment with already deployed and configured IT resources suitable for the development and deployment of applications. Three common reasons cloud consumers use PaaS: 1. The cloud consumer wants to extend on-premise environments into the cloud for scalability and economic purposes. 2. The cloud consumer uses the ready-made environment to entirely substitute an on-premise environment. 3. The cloud consumer wants to become a cloud provider and deploys its own cloud services that are made available to other external cloud consumers.

84 The PaaS delivery model relies on (and is primarily defined by) the usage of a ready-made environment that establishes a set of prepackaged products and tools used to support the entire delivery lifecycle of custom applications. The cloud service consumer is given access to a ready-made environment on a virtual server (also with contractual guarantees) but will typically not be given knowledge of any further implementation details.

85 Software-as-a-Service (SaaS) The SaaS delivery model generally represents a product that exists as a shared cloud service offered by a cloud provider to cloud consumers. The cloud consumer leases the cloud service from the cloud provider, who is responsible fro maintaining the cloud service s underlying IT resources. SaaS offerings are typically provided so that cloud consumers can gain access to the cloud service with minimal up-front effort.

86 Software-as-a-Service (SaaS) The cloud service consumer is given access the cloud service contract, but not to any underlying IT resources or implementation details.

87 Software-as-a-Service (SaaS) Unlike with IaaS and PaaS models, the SaaS delivery model does not provide cloud consumers with administrative control over the cloud service or its IT resources. Cloud consumers are granted usage control over the cloud service administrative control is retained by the cloud provider.

88 Software-as-a-Service (SaaS) from a customer perspective

89 Administrative Control The three delivery models differ with respect to the functionality and the level of administrative control provided to cloud consumers.

90 Activities Control Typical activities carried out by cloud consumers and cloud providers in relation to the cloud delivery models

91 Administrative Control - IaaS With the IaaS delivery model: The cloud provider will typically have full administrative control over the physical hardware, physical network, storage devices, and virtualization platforms. The cloud consumer will typically have full or partial administrative control over virtual servers, databases, cloud service implementations, and security settings.

92 Administrative Control - PaaS With the PaaS delivery model: The cloud provider will typically have full administrative control over all items listed under the IaaS model, plus virtual servers and databases. The cloud consumer s administrative control is limited to the readymade environment(instead of accessing server settings directly, administrative configuration are made via custom front-end provided by the ready-made environment).

93 Administrative Control - SaaS With the SaaS delivery model: The cloud provider will typically have full administrative control over all items listed under the IaaS model, plus virtual servers and databases and often the service implementation itself. The cloud consumer s administrative control is limited to service implementation which can be configured via a custom front-end.

94 Combining Cloud Delivery Models As pointed out with each of the three preceding scenarios, there are common steps to realizing each of the three cloud delivery models. This highlights a natural layered relationship between the three delivery models providing cloud providers with the option of establishing one cloud delivery model by leveraging IT resources from another. The following pages explore common combinations of cloud delivery models.

95 IaaS +PaaS To set up a PaaS environment a cloud provider can leverage physical and/ or virtual servers provided by an existing IaaS environment. The PaaS ready-made environments are built upon virtual servers and physical servers provided by a separate IaaS environment.

96 IaaS +PaaS The decision by a cloud provider to lease IT resources from another cloud provider can be economical or it may be influenced by cloud consumer requirements. For example, a cloud consumer may have a legal requirements for data to be physically stored in a specific region (for which the cloud provider needs to contract a different cloud provider).

97 IaaS + PaaS +SaaS All three cloud delivery models can be combined to establish layers of IT resources that build upon each other. Using the ready-made environment provided by PaaS, a cloud consumer organization can develop and deploy its own SaaS cloud service that it can then make available as a commercial product.

98 The SaaS product is developed using a PaaS ready-made environment and implemented upon virtual severs and physical servers provided by a separate IaaS environment.

99

100 Cloud Deployment Models

101 Overview A cloud deployment model represents a specific type of cloud environment, primarily distinguished by ownership and size. There are four common deployment models: Public Cloud Community Cloud Private Cloud Hybrid Cloud (Variations of these deployment models can also exist)

102 Public Cloud A public cloud is a publically accessible cloud environment owned by a third-party cloud provider. The IT resources (usually offered via the previously described delivery models) on public clouds are generally offered to cloud consumers at a cost. The cloud provider is responsible for the creation and on-going maintenance of the public cloud and its IT resources.

103 Many notable IT vendors provide public clouds.

104 Many notable IT vendors provide public clouds.

105 Community Cloud A community cloud is similar to a public cloud except that its access is limited to a specific community of cloud consumers. The community cloud may be jointly owned by the community member or it may be owned by a third-partu cloud provider that provisions a public cloud with limited access. The member cloud consumers of the community typically share the responsibility for defining and evolving the community cloud. However, membership in the community does not necessarily guarantee access or control to the cloud s IT resources.

106 An example of a community of organizations accessing IT resources from a community cloud.

107 Private Cloud A private cloud is owned by a single organization. Private clouds enable an organization to use cloud computing technology as a means of centralizing access to IT resources by different parts of the organization. The use of a private cloud can change how organizational and trust boundaries are defined and applied. The actual administration of a private cloud environment may be carried out by internal or outsourced staff.

108 Private Cloud External private clouds can effectively extend on-premise infrastructure to IT resources that are physically isolated in the private cloud environment through the use of a virtual primate network (VPN).

109 Private Cloud With a private cloud, the same organization is technically both the cloud consumer and cloud provider. In order to differentiate these roles: a separate organizational department typically assumes the responsibility for provisioning the cloud (and therefore assumes the cloud provider role) departments requiring access to the private cloud assume the cloud consumer role

110 Hybrid Cloud A hybrid cloud is a cloud environment of two or more different cloud deployment models. For example, a cloud consumer may choose to deploy cloud services processing sensitive data to a private cloud and nonsensitive cloud services to a public cloud. The result of this combination is a hybrid deployment model. Hybrid deployment models can be complex and challenging to create and maintain.

111 An organization using a hybrid cloud model, which utilizes both a private cloud and a public cloud.

112 Benefits of Cloud Computing

113 Benefits of Cloud Computing The following represent the primary benefits of cloud computing: Reduced Investment and Proportional Costs Increased Scalability Increased Availability and Reliability

114 Reduced Investment and Proportional Costs By using virtualization, a cloud provider can offer the same IT resource to multiple cloud consumers. Cloud consumers that use cloud-based IT resources can generally lease them with a pay-for-use model. With this model, cloud consumers pay a usage fee for only the amount of the IT resource actually used, resulting in directly proportional costs. This gives an organization access to IT resources without having to purchase its own, resulting in reduced investment requirements.

115 Reduced Investment and Proportional Costs By lowering required investments and incurring costs that are proportional to their needs, cloud consumers can scale their IT enterprise effectively and pro-actively. As an example, this chart compares the costs of on-premise IT resources with the costs of cloud-based IT resources over a three-year period.

116 Increased Scalability IT resources can be flexibly acquired from a cloud provider, almost instantaneously and at a wide variety of usage levels. By scaling with cloud-based IT resources, cloud consumers can leverage this flexibility to increase their responsiveness to foreseen changes and unforeseen changes. This holds true for when a cloud consumer needs to scale IT resources, based on current requirements.

117 Increased Scalability The depicted example illustrates the variation of demand for an application server during a period of 24 hours, measured in concurrent users. Assuming one server from a given cloud provider is able to handle 2,000 concurrent user, the cloud consumer can adjust the usage as necessary (in this case between 1 and 5 servers) and pay only for the hours of server usage.

118 Increased Availability and Reliability An IT resource with increased availability is available for longer periods of time (for example, 22 hours out of a 24 hour day). An IT resource with increased reliability is able to better avoid and recover from exception conditions. Cloud providers generally offer resilient IT resources for which they are able to guarantee high levels of availability. Cloud environments can be based on a modular architecture that provides extensive failover support to further increase reliability. Note that availability and reliability are explained in detail in the Service Level Agreements section.

119 Increased Availability and Reliability In the upcoming example, a cloud transparently provides increased availability and reliability. During the two illustrated message exchanges, the cloud service consumer is unaware it is interacting with different implementations of Cloud Service A located in different geographical regions. There are many different types of cloud-based technology architectures that can be created to support this benefit, including the option for one cloud to leverage IT resources in another cloud.

120 The details for each step are provided on the next page.

121 Increased Availability and Reliability 1. The cloud service consumer invokes capability1 of Service A. Service A is a cloud-based service that is physically implemented on a server residing in a specific geographic region (Region 1). 2. Cloud Service A replies with the expected response message. 3. The next time the cloud service consumer attempts to invoke the same capability of the same service, the cloud determines that the previous implementation (the one residing in Region 1) is currently unavailable. The request message is therefore automatically routed to a different implementation of Cloud Service A, which resides in a different geographic region (Region 2). 4. Cloud Service A replies with the expected response message.

122 Challenges of Cloud Computing

123 Challenges of Cloud Computing The following are common cloud computing adoption challenges: Increased Security Vulnerabilities Reduced Operational Governance Control Limited Portability Between Cloud Providers Multi-Regional Compliance and Legal Issues Note that all of these challenges pertain primarily to cloud consumers that use IT resources located in public clouds (as explained in the Cloud Deployment Models section).

124 Increased Security Vulnerabilities The remote usage of IT resources requires an expansion of trust boundaries by the cloud consumer to include an external cloud. Unless the cloud consumer and cloud provider support the same or compatible security technologies, it can be difficult to establish a security architecture that spans the trust boundary without introducing vulnerabilities. Furthermore, because cloud-based IT resources can be shared, there can be overlapping trust boundaries from different cloud consumers (as illustrated on the following page).

125 Increased Security Vulnerabilities In the example on the following page, two organizations accessing the same cloud service are required to extend their respective trust boundaries to the cloud, resulting in overlapping trust boundaries. It can be difficult for a cloud provider to offer security technologies that accommodate the security requirements of both cloud service consumers. Furthermore, the fact that trust boundaries overlap can lead to opportunities for an attacker to attack IT resources shared by multiple cloud consumers.

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127 Reduced Operational Governance Control When forming dependencies on externally cloud-hosted IT resources, cloud consumers are almost always given a lower level of governance control when compared to on-premise IT resources. This reduced level of control can introduce risks pertaining to how a cloud is operated by the cloud provider, as well as external connections between the cloud consumer and the cloud. Cloud consumers are often required to rely on Service Level Agreements (SLAs) and other warranties made by the cloud provider.

128 Reduced Operational Governance Control This challenge can relate to the organization providing a cloud or the external connections required to communicate with the cloud. For example: An unreliable cloud provider may not maintain guarantees it makes in the SLAs published for its cloud services. This can jeopardize the quality of cloud consumer solutions that rely on these cloud services. The geographic distance between the cloud consumer and cloud provider can require additional network hops that introduce fluctuating latency and potential bandwidth constraints. This can also jeopardize the quality of cloud consumer solutions that rely on cloud services.

129 Reduced Operational Governance Control Legal contracts, combined with SLAs, technology inspections, and monitoring can mitigate these risks. However, with public clouds, there is always a risk that the cloud provider will be acquired or may go out of business, potentially resulting in an inability to fulfill legal obligations. This, combined with the Limited Portability challenge (explained shortly), can have significantly restrictive impacts on the cloud consumer. Note that SLAs are explained in detail in the Service Level Agreements section.

130 Example of an Unreliable Cloud Provider Because a cloud provider has more governance control than the cloud consumer, it may be able to make changes to IT resources without the cloud consumer's permission. The diagrams on the right depict an example whereby an irresponsible cloud provider performs a non-backwardscompatible upgrade of the messaging technology. The details for each step are listed on the next page.

131 Reduced Operational Governance Control 1. The cloud service consumer accesses cloud services (not shown) hosted on a virtual server. Both the cloud service consumer and the cloud services are designed to support the exchange of messages based on the SOAP 1.1 industry standard. 2. Without informing the cloud consumer, the cloud provider upgrades the virtual machine so that it can now only support messages based on the SOAP 1.2 industry standard. (The tact that this upgrade is nonbackwards compatible to SOAP 1.1 may be accidental.) 3. The cloud service consumer is no longer able to access cloud services on the virtual server using SOAP 1.1 compliant messages. Note that different cloud delivery models will offer different levels of operational and governance control. This example is specific to the SaaS delivery model, as explained in the Cloud Delivery Models section.

132 Reduced Operational Governance Control Example of an Unreliable Network The following diagram explains that despite the cloud consumer and cloud provider each having reliable networks, the network connection between their respective environments can still jeopardize communication.

133 Reduced Operational Governance Control Example of an Unreliable Network (continued) A cloud consumer has a local area network with a robust bandwidth of 1 Gbps. The cloud provider also has a robust local area network with a bandwidth of 1 Gbps. The network connecting the cloud consumer and cloud provider has a bandwidth of 100mbps. The connection from the cloud consumer to the cloud provider over the Internet is also subjected to variable speeds and network hops that further limit throughput. The total throughput for communications between cloud consumer and cloud provider is limited to a bandwidth of 100mbps, plus additional fluctuations.

134 Limited Portability Between Cloud Providers Due to a lack of established industry standards within the cloud computing industry, individual public clouds are proprietary to various extents. For cloud consumers that have custom-built solutions with dependencies on these proprietary environments, it can be challenging to move from one cloud provider to another. This challenge can be mitigated if cloud consumers can build solutions based on industry standards and if cloud providers support these industry standards. Note that this challenge is especially relevant for PaaS and laas delivery models.

135 As an example, a cloud consumer may be unable to migrate an application from Cloud A to Cloud B because the cloud provider of Cloud B does not support the same security technologies as Cloud A.

136 Multi-Regional Compliance and Legal issues Cloud consumers will often not have information regarding the physical location of the IT resources provided by third party cloud providers. Depending on the nature of the cloud consumer s business, there may be industry or government regulations and policies that impose specific legal requirements. For example, the Payment Card Industry Data Security Standard (PCI DSS) requires that cardholder data be stored in separated network segments. Cloud consumers unaware of the location of data or IT resources hosted by cloud providers may not be able to comply with such regulations and policies.

137 Multi-Regional Compliance and Legal issues Another regional legal issue that can pose problems is the disclosure of cloud hosted data. A cloud consumer may be unaware that a cloud provider is physically locating the cloud consumer's storage device in a country where the risk of data being disclosed is higher than in other countries. For example, data stored in the United States by a EU- based cloud consumer can be easier accessed than data stored in EU countries due to the enactment of the USA PATRIOT act. Reputable cloud providers can generally provide guarantees that these types of compliance and legal concerns are addressed.

138 Business Cost Metrics

139 Overview Metrics are measured statistics collected for analysis purposes. This section focuses on the following core metrics used to evaluate the estimated costs and business value of leasing cloud-based IT resources when compared to the purchase of on-premise IT resources. Up-front Costs On-going Costs The following additional cost metrics are also described: Cost of Capital Sunk Costs Integration Costs Locked-in Costs

140 Up-front Costs Up-front costs represent the initial investment required by the organization to fund the IT resources it requires. Up-front costs for the purchase and deployment of on-premise IT resources tend to be high. Examples of up-front costs for on-premise environments can include hardware, software and the labor required for deployment. Up-front costs for the leasing of cloud-based IT resources tend to be low. Examples of up-front costs for cloud-based environments can include the labor costs required to assess and set up a cloud environment.

141 On going- Costs On-going costs represent the expenses required by the organization to run and maintain IT resources it uses. On-going costs for the operation of on-premise IT resources can vary. Examples of on-going costs for on-premise environments can include licensing fees, electricity, insurance, and labor. On-going costs for the operation of cloud-based IT resources can also vary, but often exceed the on-going costs of on-premise IT resources (especially over a longer period of time). Examples of on-going costs for cloud-based environments include virtual hardware leasing fees, bandwidth usage fees, licensing fees and labor.

142 Up-front Costs and On-going Costs The following is an example metrics analysis: Let s assume an organization requires three new physical servers. The purchase price of one server is $7,000 and the monthly lease cost of the same server from a cloud provider is $1,000. The organization chooses to calculate the up-front and on-going costs for the usage of the servers over a period of three years. The table on the next page provides a sample comparison of up-front and on-going costs for on-premise and cloud-based environments.

143 Up-front Costs and On-going Costs Over a period of three years, the onpremise environment would cost the organization $163,100 based on the following calculation: $33,500 up-front cost + ($3,600 on-going costs x 36 months) Over a period of three years, the cloudbased environment would cost the organization $158,500 based on the following calculation: $100 up-front cost + ($4,400 on-going costs x 36 months)

144 Up-front Costs and On-going Costs The preceding analysis assumes the three servers will be fully used over the three-year period. However, in most cases, the usage requirements of an organization will fluctuate. This is where the elasticity characteristic of cloud environments can have a significant impact on on-going usage costs. Let s assume that, over the three-year period, the organization will actually require a maximum of 3 servers, a minimum of 1 server and 2 servers on average. The table on the next page shows the adjusted costs.

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146 Up-front Costs and On-going Costs The on-premise costs remain unchanged. The cloud-based up-front cost has been increased to reflect the additional labor required to set-up the scalability parameters for the use of one to three servers. The cloud-based on-going cost has been decreased to represent the fact that, on average, less IT resources will be used. The result is a decrease of the cloud-based costs to a total of $124,900 over the three year period.

147 Additional Metrics The preceding analysis provides a basic insight into the primary cost metrics for evaluating the usage cloud-based IT resources. However, this type of analysis can be more complex, as there are additional metrics that can be taken into account, depending on a given organization's unique requirements and circumstances. The next pages describe the following additional types of metrics: Cost of Capital Sunk Costs Integration Costs Locked-in Costs

148 Cost of Capital The cost of capital is a value that represents the cost incurred by raising required funds. For example, it will generally be more expensive to raise an initial investment of $150,000 than it will be to raise this amount over a period of three years. The relevancy of this cost depends on how the organization goes about raising the funds it requires. If the cost of capital for an initial investment is high, then it further helps justify the leasing of cloud-based IT resources.

149 Sunk Costs An organization will often have existing IT resources that are already paid for and operational. The prior investment that has been made in these on-premise IT resources is referred to as sunk costs. When comparing cloud-based IT resources to on-premise IT resources with sunk costs, the up-front costs for on-premise IT resources is significantly lower. It can therefore be more difficult to justify the leasing of cloudbased IT resources as an alternative.

150 Integration Costs Integration testing is a form of testing required to measure the effort required to make IT resources compatible and interoperable within a new environment, such as a new cloud platform. Depending on the cloud deployment model and cloud delivery model being considered by an organization, there may be the need to further allocate funds to carry out integration testing and additional labor related to enable interoperability between cloud service consumers and cloud services. These expenses are referred to as integration costs. High integration costs imposed by cloud providers can make the option of leasing cloud-based IT resources less appealing.

151 Locked-in Costs As explained earlier in the Challenges of Cloud Computing section 24, cloud environments can impose portability limitations. When performing a metrics analysis over a longer period of time, it may be necessary to take into consideration the possibility of having to move from one cloud provider to another. Due to the fact that cloud service consumers can become dependent on proprietary characteristics of a cloud environment, there are lockedin costs (primarily related to labor) associated with this type of move. Locked-in costs can further decrease the long-term business value of leasing cloud-based IT resources.

152 Service Level Agreements (SLAs)

153 Service Level Agreements A Service Level Agreement (SLA) is a document that describes quality-of-service features, behaviors, and limitations of a service. An SLA can be considered a human-readable part of a service contract that extends the technical service contract. Because cloud environments intentionally hide back-end implementation details about cloud services, the guarantees expressed in SLAs become very important to cloud consumers.

154 Service Level Agreements A typical SLA document for a cloud service will cover three specific quality-of-service characteristics: availability reliability performance The following sections describe each of these characteristics separately.

155 Service Level Agreement: Availability The availability of an IT resource is the probability that it will be accessible. The probability value is generally expressed with a percentage representing the amount of time that the IT resource is accessible during a given period. The percentage is calculated as follows: 1. Divide the amount of hours the IT resource was unavailable (within a measured period) by the total amount of hours within the measured period. 2. Multiply the value by Deduct the value from 100.

156 Service Level Agreements: Availability For example, let's take a Web service that was unavailable for 18 hours over the course of a year (24 x 365 = 8,760 hours): 18 hours / 8,760 hours = x 100 = = 99.8 The availability rating of the Web service for the measured period is 99.8%.

157 Service Level Agreements: Availability The availability value guaranteed in the SLA is based on assumptions regarding future downtimes. Future downtimes are estimated by assigning the event that causes a downtime a probability for its occurrence and the time it would take to bring up the IT resource again. The percentage is calculated as follows: 1. Multiply the probability of downtime by the actual estimated downtime. 2. Divide the value by a measured period of time. 3. Multiply the value by Deduct the value from a 100.

158 Service Level Agreements: Availability For example, a Web service may rely on a network that has a 20% probability of crashing over the course of a year, plus it is further estimated that it would take 12 hours to recover: 0.2 x 12 hours = / 8,670 = x100 = = (rounded to two decimals) The availability rating of the network for the measured period is 99.97%.

159 Service Level Agreements: Reliability Reliability represents the probability that an IT resource performs its intended functions without failure under pre-defined conditions. A common formula tor calculating the reliability rating of an IT resource, is to take the number of successful executions of its function(s) and divide that value by the number of attempts made to execute those function(s). Multiple the result by 100 to determine the reliability percentage.

160 Service Level Agreements: Reliability For example, let's take a Web service that received 3,000 invocation attempts over a given period, but only executed 2,892 of those attempts successfully: 2,892 /3,000 = x100 = 96.4 The reliability rating of the Web service during the measured period is 96.4%. Reliability is closely related to availability because, in order to be reliable, the IT resource needs to be available.

161 Service Level Agreements: Performance The maximum performance of an IT resource represents the capacity up to which the IT resource is able to perform its functions. The determination of this capacity (the performance rating) of a given IT resource depends on its type and purpose. For example, a Web service's performance rating could be specified in calls per seconds and the response time for each call. A development environment, on the other hand, may measure capacity in the maximum number of concurrent users that can be supported.

162 Service Level Management Agreements Types There are three types of SLM agremeents: Service Level Agreement (SLA) Operational Level Agreement (OLA) Underpinning Contracts (UC)

163 Service Level Management Agreements Types OLA : An Agreement between an IT Service Provider and another part of the same Organization. An OLA supports the IT Service Provider's delivery of IT Services to Customers. The OLA defines the goods or Services to be provided and the responsibilities of both parties. For example there could be an OLA between the: IT Service Provider and a procurement department to obtain hardware in agreed times Service Desk and a Support Group to provide Incident Resolution in agreed times.

164 Service Level Management Agreements Types UC : A Contract between an IT Service Provider and a Third Party. The Third Party provides goods or Services that support delivery of an IT Service to a Customer. The Underpinning Contract defines targets and responsibilities tat are required to meet agreed Service Level Targets in an SLA.

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175 THE WORLD HAS CHANGED!

176 In 1999: 38M people had broadband internet Today: 1.3B people have it on their mobile phones Ctrlaltdeletebook.com

177 The world is changing has changed MOBILITY: 1,3 billion world s mobile worker population will be reached by 2015 SOCIAL: 65% of companies are deploying at least one social software tool CLOUD: 70% of business are either using or investigating cloud computing solutions ANALYTICS: Big Data market is growing 40% every year to reach $17 billion by 2015

178 IDC Prediction 3rd Platform will dominate growth 3rd Platform will cannibalize 2nd Platform Value migrating within 3rd Platform

179 The CLOUD takes shapes The key objectives behind your approach to cloud adoption? Business executives are starting to appreciate the potential transformative value of cloud

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