FIRST LESSON OF CLOUD COMPUTING V.1.0.0

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nwclasantha
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FIRST LESSON OF CLOUD COMPUTING V.1.0.0

Post by nwclasantha » Thu Sep 12, 2013 12:47 pm

FIRST LESSON OF CLOUD COMPUTING V.1.0.0

What is Cloud?

According to the National Institute of Standards and Technology (NIST), "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."

The NIST definition lists five essential characteristics of cloud computing:

On-demand Self-service
Broad Network Access
Resource Pooling
Rapid Elasticity or Expansion
Measured Service
diagram-cloud-computing-characteristics.png
On-demand Self-service

With on-demand self-service, cloud consumers can unilaterally provision or access computing resources as needed, typically using a web browser. Provisioning can be performed without requiring human interaction with either IT or a service provider organizations.

Broad Network Access

With broad network access, cloud resources become available over the network using standard protocols, often through a web browser using HTTP, HTML, XML, Java, SOAP, or other standard protocols. This promotes wide usage by heterogeneous platforms.

Resource Pooling

With resource pooling, computing resources, wherever located, are pooled together to serve multiple cloud consumers. Cloud users can then access a pool of servers that function as a single unit, and more importantly, users are not aware of the physical servers providing the resources.

Rapid Elasticity or Expansion

Computing resources are dynamically assigned, released, and reassigned according to consumer demand.

Measured Service

With measured service, cloud resources can be monitored, controlled, and reported by both users and administrators. Cloud users are able to see their own cloud usage while cloud administrators can see the entire cloud usage. Measured service can also include showback and chargeback, where the cost of resources used can be displayed or calculated per user, per department, or per organization.
cloud-models.jpg
Cloud Classifications

Given the broad definition of the term "cloud," the current taxonomy differentiates clouds both in terms of cloud service and cloud deployment models.

Infrastructure as a Service (IaaS):

IaaS clouds provide access to collections of virtualized computer hardware resources, including machines, network, and storage. With IaaS, users assemble their own virtual cluster on which they are responsible for installing, maintaining, and executing their own software stack. The most popular example is Amazon Web Services (AWS).

With IaaS, users are provided with raw compute resources which are typically virtual machines, including CPU, memory, storage, and network resources as well as the operating system. The IaaS user manages and controls everything except the underlying hardware and network resources.

Platform as a Service (PaaS):


PaaS-style clouds provide access to a programming or runtime environment with scalable compute and data structures embedded in it. With PaaS, users develop and execute their own applications within an environment offered by the service provider. Popular examples include Microsoft Azure and Google App Engine.

With PaaS, a software development environment is delivered to users with software development tools and the necessary CPU, memory, storage, and network resources. Users are limited to the languages and tools provided by the PaaS provider and application portability is not guaranteed.

Software as a Service (SaaS):

SaaS-style clouds deliver access to collections of software application programs. SaaS providers offer users access to specific application programs controlled and executed on the provider's infrastructure. Popular examples include Salesforce, DropBox, and Workday.

With SaaS, users have no control of the application infrastructure and do not have complete application management or control. The SaaS provider maintains the application and user data as well as provides the storage and/or backup. SaaS is a simple and quick way to implement applications.

Cloud Deployment Models

A cloud deployment model defines where the physical servers are deployed and who manages them.
diagram-cloud-deployment-models.png
Public Clouds

Public clouds provide access to computing resources for the general public over the Internet but the resources themselves are owned by the organization selling the cloud services. The public cloud provider allows customers to self-provision resources typically via a web service interface. Customer's rent access to resources as needed on a pay-as-you-go basis. Public clouds offer access to large pools of scalable resources on a temporary basis without the need for capital investment in data center infrastructure.

With public cloud, infrastructure costs are shared across customers, which result in economies of scale. Data control might be an issue depending on a number of factors, including the type and sensitivity of the data as well as the industry and local laws concerning the data.

Private Clouds

Private clouds give users immediate access to computing resources hosted within an organization's infrastructure and the resources are dedicated solely for that organization's use. Users self-provision and scale collections of resources drawn from the private cloud, typically via web service interface, just as with a public cloud. However, because it is deployed within the organization's existing data center—and behind the organization's firewall—a private cloud is subject to the organization's physical, electronic, and procedural security measures and thus offers a higher degree of security over sensitive code and data.

With private cloud, the performance of physical hardware can be controlled and maintained by the organization, and can thus markedly improve data center efficiency while reducing operational expense.

Hybrid Clouds

Hybrid clouds combine one or more public clouds and one or more private clouds by technology that enables data and application migration between them. Hybrid clouds typically use a shared API to enable hybrid operation.

With hybrid cloud, organizations can utilize the cost benefits of a public cloud and when needed, protect confidential data in a private cloud.

Virtualization and Cloud Computing

Virtualization is the ability to run multiple, isolated "virtual machines" on top of a "hypervisor." A virtual machine (VM) is a software implementation of a machine (i.e., a computer) that executes programs like a physical machine. Each VM includes its own kernel, operating system, supporting libraries and applications. A hypervisor provides a uniform abstraction of the underlying physical machine.

Multiple VMs can execute simultaneously on a single hypervisor. The decoupling of the VM from the underlying physical hardware allows the same VM to be started on different physical machines. Thus virtualization is seen as an enabler for cloud computing, but virtualization, even highly automated virtualization, is not cloud computing.

While virtualization provides isolated access, it does not associate this access with an authenticated user for security and charging purposes. Operating system virtualization and hypervisors provides unauthenticated isolation of CPUs and memories, but not a private inter-VM network and not per-allocation persistent storage.

Cloud computing authenticates/authorizes users and then provides them with self-service billable access, private secure inter-VM networks, and quality of service guarantees. Clouds also provide a way for a cloud administrator to define either Service Level Agreements (SLAs) or Quality-of-Service (QoS) specifications that categorize the quality of access (and the resulting charging rate) individual users will experience. In plain virtualization, the notion of QoS or SLA is not exported to the end user as a way of enabling self-service provisioning.

Cloud Administrator

A Cloud Administrator is responsible for the implementation, monitoring and maintenance of the cloud within the organization. Typically this role also involves the implementation of service level agreements (SLA) for permissions, access, quotas, etc. as required by an organization&rslquo;s policies. The Cloud Administrator works directly with System, Network and Cloud Storage Administrators.

Cloud Application Architect

The Cloud Application Architect is responsible for adapting, porting or deploying an application to a target cloud. They work closely with end users to ensure that an application's performance, reliability and security are all maintained throughout the life-cycle of the application. The architect's skills draw from both system administration experience (to tune the underlying OS and to act as System Administrator on instances) and from domain specific expertise (to tune the application and understand end user needs). Typically there is one architect per application domain who works closely with the Cloud Data Architect and the Cloud Administrators.

Cloud Architect

The Cloud Architect will determine when and how a private cloud meets the policies and needs of an organization's strategic goals. The Cloud Architect is also responsible for designing the private cloud, understanding and evaluating the technologies and vendors needed to deploy the private cloud.

Cloud Data Architect

The cloud offers many different types of storage with possibly different SLAs associated with each of them. The Cloud Data Architect makes sure that an application in the cloud is using these different storage types appropriately, and that the application is taking full advantage of the properties of each type of cloud storage.

Cloud Developer

Cloud Developers develop for the cloud infrastructure itself. This can be a developer working on a client tool (such as the euca2ools suite) or a system component such as the Eucalyptus Cloud Controller. Typically Cloud Developer's work independently, though they may interact with the Cloud Administrator during debugging sessions.

Cloud Operator

The duties of a Cloud Operator tend to relate to day-to-day cloud maintenance and monitoring activities and are considered by most as a junior Cloud Administrator.

Cloud Service Manager

The Cloud Service Manager design the policies, rules and pricing model (SLA) for every cloud resource available within the organization. The SLA will need to stay current with the organization's policies, rules and priorities, thus the Cloud Service Manager works with the management to receive directions and with the Cloud Administrator to implement the SLAs.

Cloud Storage Administrator

The Cloud Storage Administrator writes SLAs for the various groups and users (maps space, bandwidth, and reliability of the various cloud storage to the various groups/users), to ensure SLAs stay in compliance with current policies and that SLAs are met and respected. The Cloud Storage Administrator works directly with the Storage, Network and Cloud Administrators.

Cloud User

A Cloud User has access to compute resources (pre-packaged images, instances, volumes, buckets etc.) within a cloud, and are generally granted System Administrator privileges to the instances they start. Cloud Users may work with a Cloud Architect to tune specific applications, but often use the images provide to them independently.

2ND LESSON WILL BE COMING SOON...!

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