Cloud_Computing_An_Introduction_Chapter_1.pdf
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Cloud computing is the delivery of computing services – like servers, storage, databases, networking, software, analytics, and intelligence – over the Internet ("the cloud"). Instead of managing physical hardware, users access these services on demand, paying only for what they use, which offers flexibility, scalability, and cost savings.
Cloud_Computing_An_Introduction_Chapter_1.pdf
- 1. Cloud Computing: An Introduction Manash Kumar Mondal Department of Computer Science and Engineering University of Kalyani Code: MCA304 1 / 46
- 2. Contents 1. Origin and Influences 2. Basic Concepts and Terminology 3. Goals and Benefits 4. Risks and Challenges 2 / 46
- 3. Origin and Influences 3 / 46
- 4. A brief History John McCarthy publicly proposed in 1961 “If computers of the kind I have advocated become the computers of the future, then computing may someday be organised 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 1960, a chief scientist of ARPANET “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’...”. 4 / 46
- 5. Begining... • In the late 1990s, salesforce.com pioneered the notion of bringing remotely provisioned services into the enterprise. • 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, 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 5 / 46
- 6. Definitions I NIST Definition Cloud computing is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. Gartner “...a style of computing in which scalable and elastic IT-enabled capabilities are delivered as a service to external customers using Internet technologies.”. 6 / 46
- 7. Definitions II Forrester Research “...a standardised IT capability (services, software, or infrastructure) delivered via Internet technologies in a pay-per-use, self-service way.”. Thomas Erl “Cloud computing is a specialized form of distributed computing that introduces utilization models for remotely provisioning scalable and measured resources”. 7 / 46
- 8. Technology Innovations • Cluster Computing • Grid Computing • Virtualization 8 / 46
- 9. Cluster Computing Cluster computing Cluster computing is a type of computing where multiple computers are connected so they work together as a single system. The term “cluster”refers to the network of linked computer systems programmed to perform the same task. • A cluster is a group of independent IT resources • Interconnected and work as a single system. • System failure rates are reduced • Availability and reliability are increased, 9 / 46
- 10. Grid Computing • A computing grid (or computational grid) • Provides a platform in which computing resources are organised into one or more logical pools. • These pools are collectively coordinated to provide a high performance distributed grid, sometimes referred to as a super virtual computer. • Unlike clustering in that grid systems are much more loosely coupled and distributed. • Grid computing systems can involve computing resources that are heterogeneous and geographically dispersed, which is generally not possible with cluster computing-based systems. 10 / 46
- 11. Cluster vs Grid Computing Cluster Computing • Tightly connected nodes • Same physical location (LAN) • Centralized resource management • Homogeneous systems • Low latency, high performance • Used in simulations, HPC tasks Grid Computing • Loosely connected nodes • Geographically distributed (WAN) • Distributed resource management • Heterogeneous systems • Higher latency, highly scalable • Used in large-scale data analysis, SETI@home 11 / 46
- 12. Virtualization • Virtualization represents a technology platform used for the creation of virtual instances of IT resources. • A layer of virtualization software allows physical IT resources to provide multiple virtual images of themselves so that their underlying processing capabilities can be shared by multiple users. • As cloud computing evolved, a generation of modern virtualization technologies emerged to overcome the performance, reliability, and scalability limitations of traditional virtualization platforms. 12 / 46
- 13. Enabling Technologies • Broadband Networks and Internet • Architecture • Data Center Technology • (Modern) Virtualization Technology • Web Technology • Multitenant Technology • Service Technology 13 / 46
- 14. Basic Concepts and Terminology 14 / 46
- 15. Cloud A cloud refers to a distinct IT environment that is designed for the purpose of remotely provisioning scalable and measured IT resources. Figure: Cloud 15 / 46
- 16. IT Resource Figure: IT Resource • An IT resource is a physical or virtual IT-related artifact that can be either software-based, such as a virtual server or a custom software program, or hardware-based, such as a physical server or a network device. Figure: IT Resource. 16 / 46
- 17. Cloud Consumers and Cloud Providers • The party that provides cloud-based IT resources is the Cloud Provider. • The party that uses cloud-based IT resources is the cloud consumer. • These terms represent roles usually assumed by organizations in relation to clouds and corresponding cloud provisioning contracts. 17 / 46
- 18. Scaling • Scaling, from an IT resource perspective, represents the ability of the IT resource to handle increased or decreased usage demands. • Two Types of Scaling - • Horizontal Scaling- scaling out and scaling in • Vertical Scaling- scaling up and scaling down 18 / 46
- 19. Horizontal Scaling • The allocating or releasing of IT resources that are of the same type is referred to as horizontal scaling. • The horizontal allocation of resources is referred to as scaling out. • The horizontal releasing of resources is referred to as scaling in. • A common form of scaling within cloud environments. 19 / 46
- 20. Vertical Scaling • When an existing IT resource is replaced by another with higher or lower capacity. • The replacing of an IT resource with another that has a higher capacity is referred to as scaling up. • The replacing an IT resource with another that has a lower capacity is considered scaling down • Less common in cloud environments due to the downtime required while the replacement is taking place. Figure: Vertical Scaling 20 / 46
- 21. Horizontal vs. Vertical Scaling in Cloud Computing Table: Comparison of Scaling Methods Feature Horizontal (Out) Vertical (Up) Method Add instances Increase resources Hardware Multiple VMs/servers Single VM/server Cost Cost-effective at scale Expensive at limits Complexity More complex (load balancing) Simpler (single machine) Downtime Minimal/none Possible for upgrades Fault Tolerance High Low Scalability High (many machines) Limited (hardware limits) Use Cases Web apps, big data Small apps, predictable loads • Horizontal scaling provides better fault tolerance and scalability. • Vertical scaling is simpler to manage but has hardware limitations. 21 / 46
- 22. Cloud Service • A cloud service is any IT resource that is made remotely accessible via a cloud • A cloud service can exist as a simple Web-based software program with a technical interface invoked via the use of a messaging protocol, • or as a remote access point for administrative tools or larger environments and other IT resources. Figure: Cloud Service 22 / 46
- 23. Cloud Service (Cont...) • The driving motivation behind cloud computing is to provide IT resources as services that encapsulate other IT resources, while offering functions for clients to use and leverage remotely • A multitude of models for generic types of cloud services have emerged, most of which are labeled with the “as-a-service”suffix 23 / 46
- 24. QoS through SLA • Cloud service usage conditions are typically expressed in a service-level agreement (SLA) • It is the human-readable part of a service contract between a cloud provider and cloud consumer • Describes Quality of Service (QoS) features, behaviours, and limitations of a cloud-based service or other provisions. • An SLA provides details of various measurable characteristics related to IT outcomes, such as uptime, security characteristics, • Provides QoS features, including availability, reliability, and performance • Since the implementation of a service is hidden from the cloud consumer, an SLA becomes a critical specification. 24 / 46
- 25. Cloud Service Consumer • The cloud service consumer is a temporary runtime role assumed by a software program/hardware when it accesses a cloud service • Cloud service consumers can include software programs and services capable of remotely accessing cloud services with published service contracts • Hardware like Workstations, laptops and mobile devices running software capable of remotely accessing other IT resources positioned as cloud services. 25 / 46
- 26. Benefits to cloud consumers • On-demand access to pay-as-you-go computing resources on a short-term basis (such as processors by the hour), and the ability to release these computing resources when they are no longer needed • The perception of having unlimited computing resources that are available on demand, thereby reducing the need to prepare for provisioning • The ability to add or remove IT resources at a fine-grained level, such as modifying available storage disk space by single gigabyte increment • Abstraction of the infrastructure so applications are not locked into devices or locations and can be easily moved if needed 26 / 46
- 27. Goals and Benefits 27 / 46
- 28. Cloud Service Consumer • Reduced Investments and Proportional Costs • Increased Scalability • Increased Availability and Reliability 28 / 46
- 29. Reduced Investments and Proportional Costs • Public cloud providers base their business model on the mass-acquisition of IT resources • These resources are made available to cloud consumers via attractively priced leasing packages • Organisations (Consumers) gain access to powerful infrastructure without having to purchase it themselves • Negligible investment on IT resources like hardware and software purchases and their ownership • OS, middle-ware or platform software, and application software are made available to and shared by multiple cloud consumers, resulting in increased or even maximum possible utilization costs 29 / 46
- 30. An Example • A company with sizeable batch-centric tasks can complete them as quickly as their application software can scale • Using 100 servers for one hour costs the same as using one server for 100 hours • This “elasticity”of IT resources, achieved without requiring steep initial investments to create a large-scale computing infrastructure, can be extremely compelling 30 / 46
- 31. Increase Scalability 31 / 46
- 32. Increase Scalability (Cont...) • Clouds can instantly and dynamically allocate IT resources to cloud consumers, on-demand or via the cloud consumer’s direct configuration • Empowers cloud consumers to scale their cloud-based IT resources to accommodate processing fluctuations and peaks automatically or manually • Cloud-based IT resources can be released (automatically or manually) as processing demands decrease • The inherent, built-in feature of clouds to provide flexible levels of scalability to IT resources is directly related to the aforementioned proportional costs benefit • Always meet and fulfill unpredictable usage demands avoids potential loss of business that can occur when usage thresholds are met 32 / 46
- 33. Increase Availability and Reliability • Cloud environment has ability to provide extensive support for increasing the availability of a cloud-based IT resource to minimize or even eliminate outages • Increasing its reliability to minimize the impact of runtime failure conditions. • An IT resource with increased availability is accessible for longer periods of time • An IT resource with increased reliability is able to better avoid and recover from exception conditions • It is important that organizations carefully examine the SLAs offered by cloud providers when considering the leasing of cloud-based services and IT resources • Organisations are able to increase quality-of-service guarantees to customers and further reduce or avoid potential loss of business resulting from unanticipated runtime failures. 33 / 46
- 34. Risks and Challenges 34 / 46
- 35. Risks and Challenges • Increased Security Vulnerabilities • Reduced Operational Governance Control • Limited Portability Between Cloud Providers • Multi-Regional Compliance and Legal Issues 35 / 46
- 36. Increased Security Vulnerabilities • The moving of business data to the cloud means that the responsibility over data security becomes shared with the cloud provider. • The remote usage of IT resources requires an expansion of trust boundaries by the cloud consumer to include the external cloud • Cloud provider’s privileged access to cloud consumer data • The extent to which the data is secure is now limited to the security controls and policies applied by both the cloud consumer and cloud provider • The overlapping of trust boundaries and the increased exposure of data can provide malicious cloud consumers (human and automated) with greater opportunities to attack IT resources and steal or damage business data 36 / 46
- 37. Increased Security Vulnerabilities Figure: Trust Boundary 37 / 46
- 38. Reduced Operational Governance Control • Cloud consumers are usually allotted a low level of governance control than that over on-premise IT resources • This can introduce risks associated with how the cloud provider operates its cloud, as well as the external connections that are required for communication between the cloud and the cloud consumer Example • An unreliable cloud provider may not maintain the guarantees it makes in the SLAs that were published for its cloud services. This can jeopardize the quality of the cloud consumer solutions that rely on these cloud services. • Longer geographic distances between the cloud consumer and cloud provider can require additional network hops that introduce fluctuating latency and potential bandwidth constraints. 38 / 46
- 39. Unreliable Network Connection An unreliable network connection compromises the quality of communication between cloud consumer and cloud provider environments Figure: Unreliable Network Connection 39 / 46
- 40. Solutions for Governance Risks • Legal contracts, when combined with SLAs, technology inspections, and monitoring, can mitigate governance risks and issues. • A cloud governance system is established through SLAs, given the “as-a-service” nature of cloud computing. • A cloud consumer must keep track of the actual service level being offered and the other warranties that are made by the cloud provider. 40 / 46
- 41. Limited Portability Between Cloud Providers • Due to a lack of established industry standards within the cloud computing industry, public clouds are commonly 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. • Portability is a measure used to determine the impact of moving cloud consumer IT resources and data between clouds 41 / 46
- 42. Example: Limited Portability Between Cloud Providers 42 / 46
- 43. Multi-Regional Compliance and Legal Issues • Third-party cloud providers will frequently establish data centers in affordable or convenient geographical locations. • Cloud consumers will often not be aware of the physical location of their IT resources and data when hosted by public clouds • For some organizations, this can pose serious legal concerns pertaining to industry or government regulations that specify data privacy and storage policies. • For example, some UK laws require personal data belonging to UK citizens to be kept within the United Kingdom 43 / 46
- 44. Multi-Regional Compliance and Legal Issues (Cont...) • Another potential legal issue pertains to the accessibility and disclosure of data • Countries have laws that require some types of data to be disclosed to certain government agencies or to the subject of the data • For example, a European cloud consumer’s data that islocated in the U.S. can be more easily accessed by government agencies (due to the U.S. Patriot Act) when compared to data located in many European Union countries. • Most regulatory frameworks recognise that cloud consumer organizations are ultimately responsible for the security, integrity, and storage of their own data, even when it is held by an external cloud provider 44 / 46
- 45. Fundamental Concepts and Models • Roles and Boundaries • Cloud Characteristics • Cloud Delivery Models • Cloud Deployment Models 45 / 46
- 46. Thank you! 46 / 46