Question

Describe the cloud storage levels depicted.

Describe the following cloud computing principles:  

• SLA Monitor
• Hypervisor
• Resource cluster

Include a link to a company selling one of these resources.

Answer 1

While creating a site backup it is very important for the website’s security to store backups in a secure location. That is where the Cloud Storage comes in. Unfortunately, many businesses rely on outdated storage solutions (such as local servers), which may cause loss of vital data.

Cloud storage is a digital storage solution that utilizes multiple servers to store data in logical pools. The organizations buy the storage capacity from the providers to store user, organization, or application data. In the past few years, the cloud storage has grown in popularity and has become a direct challenger to local storage, mainly due to the benefits it provides:

• Security: The backups are located across multiple servers and are better protected from data loss or hacking.
• Accessibility: The data stored is accessible online regardless of location

There are two major providers in the field of cloud storage namely:

• Amazon S3: It enables file storage to multiple servers and offers file encryption wherein we can share the data publicly.
• Google Cloud: It offers unlimited storage space. It also has the ability to resume the file transfer after a failure.

Cloud computing is possible because of a technology called virtualization. Virtualization allows for the creation of a simulated, digital-only "virtual" computer that behaves as if it were a physical computer with its own hardware. The technical term for such a computer is a virtual machine. When properly implemented, virtual machines on the same host machine are sandboxed from one another, so they don't interact with each other at all, and the files and applications from one virtual machine aren't visible to the other virtual machines even though they're on the same physical machine.

Virtual machines also make more efficient use of the hardware hosting them. By running many virtual machines at once, one server becomes many servers, and a data center becomes a whole host of data centers, able to serve many organizations. Thus, cloud providers can offer the use of their servers to far more customers at once than they would be able to otherwise, and they can do so at a low cost.

Even if individual servers go down, cloud servers, in general, should be always online and always available. Cloud vendors generally back up their services on multiple machines and across multiple regions.

Users access cloud services either through a browser or through an app, connecting to the cloud over the Internet – that is, through many interconnected networks – regardless of what device they're using.

Service models of cloud computing

Software-as-a-Service (SaaS): Instead of users installing an application on their device, SaaS applications are hosted on cloud servers, and users access them over the Internet. SaaS is like renting a house: the landlord maintains the house, but the tenant mostly gets to use it as if they owned it. Examples of SaaS applications include Salesforce, MailChimp, and Slack.

Platform-as-a-Service (PaaS): In this model, companies don't pay for hosted applications; instead they pay for the things they need to build their own applications. PaaS vendors offer everything necessary for building an application, including development tools, infrastructure, and operating systems, over the Internet. PaaS can be compared to renting all the tools and equipment necessary for building a house, instead of renting the house itself. PaaS examples include Heroku and Microsoft Azure.

Infrastructure-as-a-Service (IaaS): In this model, a company rents the servers and storage they need from a cloud provider. They then use that cloud infrastructure to build their applications. IaaS is like a company leasing a plot of land on which they can build whatever they want – but they need to provide their own building equipment and materials. IaaS providers include DigitalOcean, Google Compute Engine, and OpenStack.

Formerly, SaaS, PaaS, and IaaS were the three main models of cloud computing, and essentially all cloud services fit into one of these categories. However, in recent years a fourth model has emerged:

Function-as-a-Service (FaaS): FaaS, also known as serverless computing, breaks cloud applications down into even smaller components that only run when they're needed. Imagine if it were possible to rent a house one little bit at a time: for instance, the tenant only pays for the dining room at dinner time, the bedroom while they're sleeping, the living room while they're watching TV, and when they aren't using those rooms, they don't have to pay rent on them.

FaaS or serverless applications still run on servers, as do all these models of cloud computing. But they're called "serverless" because they don't run on dedicated machines and because the companies building the applications don't have to manage any servers.

SLA monitor

An SLA monitor intercepts the exchanged messages, evaluates the interaction, and collects relevant runtime data about quality-of-service guarantees defined in the cloud service’s SLA. The data collected is stored in a repository that is part of the SLA management system

An SLA Monitoring took place after the contractual agreement to meet client expectations. The SLA Monitoring process is done by using several statistics like a systematic process of collecting the data, analyzing the data, monitoring the data, and other factors that derive the higher value to the business. Once done with monitoring, have to go with SLA reporting where you can clearly see the dashboard breakdowns with policy, time, and status where you can identify the problem areas. The SLA monitoring and reporting tools always help to meet the agreement for business applications and provide the utmost performance.

The SLA management system mechanism represents a range of commercially available cloud management products that provide features about the administration, collection, storage, reporting, and runtime notification of SLA data.

An SLA management system deployment will generally include a repository used to store and retrieve collected SLA data based on pre-defined metrics and reporting parameters. It will further rely on one or more SLA monitor mechanisms to collect the SLA data that can then be made available in near-realtime to usage and administration portals to provide ongoing feedback regarding active cloud services (Figure 1). The metrics monitored for individual cloud services are aligned with the SLA guarantees in corresponding cloud provisioning contracts.

These cloud SLA monitoring tips can help you optimize your SLAs.

1. Transparent SLA monitoring: A prerequisite
2. Organizations could use third-party monitoring to ensure effective cloud SLA monitoring and compliance
3. Organizations should opt for SLAs that best suit the business requirements, instead of going in for stringent SLAs.
4. For effective cloud SLA monitoring, ensure that availability and response time are periodically reported through Web portals.

Hypervisor

A hypervisor, also known as a virtual machine monitor or VMM, is software that creates and runs virtual machines (VMs). A hypervisor allows one host computer to support multiple guest VMs by virtually sharing its resources, such as memory and processing.

Hypervisors make it possible to use more of a system’s available resources and provide greater IT mobility since the guest VMs are independent of the host hardware. This means they can be easily moved between different servers. Because multiple virtual machines can run off of one physical server with a hypervisor, a hypervisor reduces:

• Space
• Energy
• Maintenance requirements

Types of Hypervisor –

TYPE-1 Hypervisor:
The hypervisor runs directly on the underlying host system. It is also known as “Native Hypervisor” or “Bare metal hypervisor”.It does not require any base server operating system. It has direct access to hardware resources. Examples of Type 1 hypervisors include VMware ESXi, Citrix XenServer, and Microsoft Hyper-V hypervisor.

TYPE-2 Hypervisor:
A Host operating system runs on the underlying host system. It is also known as ‘Hosted Hypervisor”.Basically, the software is installed on an operating system. The hypervisor asks the operating system to make hardware calls. Examples of Type 2 hypervisor includes VMware Player or Parallels Desktop. Hosted hypervisors are often found on endpoints like PCs.

Resource cluster

Cloud-based IT resources that are geographically diverse can be logically combined into groups to improve their allocation and use. The resource cluster mechanism is used to group multiple IT resource instances so that they can be operated as a single IT resource. This increases the combined computing capacity, load balancing, and availability of the clustered IT resources.

Resource cluster architectures rely on high-speed dedicated network connections, or cluster nodes, between IT resource instances to communicate about workload distribution, task scheduling, data sharing, and system synchronization. A cluster management platform that is running as distributed middleware in all of the cluster nodes is usually responsible for these activities. This platform implements a coordination function that allows distributed IT resources to appear as one IT resource and also executes IT resources inside the cluster.

There are two basic types of resource clusters:

• Load Balanced Cluster – This resource cluster specializes in distributing workloads among cluster nodes to increase IT resource capacity while preserving the centralization of IT resource management. It usually implements a load balancer mechanism that is either embedded within the cluster management platform or set up as a separate IT resource.
• High-Availability (HA) Cluster – A high-availability cluster maintains system availability in the event of multiple node failures, and has redundant implementations of most of all of the clustered IT resources. It implements a failover system mechanism that monitors failure conditions and automatically redirects the workload away from any failed nodes.

Advantages:

In the cluster software is automatically installed and configured, and the nodes of the cluster can be added and managed easily, so it’s very easy to deploy, it’s an open system, and very cost-effective to acquire and manage, clusters have many sources of support and supply, it’s fast and very flexible, the system is optimized for performance as well as simplicity and it can change software configurations at any time, also it saves the time of searching the net for latest drivers, The cluster system is very supportive as it includes software updates.

Disadvantages:

Cluster computing contains some disadvantages such as that it’s hard to be managed without experience, also when the size of the cluster is large, it’ll be difficult to find out something has failed, the programming environment is hard to be improved when software on some node is different from the other.

The link to the company which sells Hypervisor: https://www.vmware.com/in.html

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