Name three Cloud Computing Patterns and explain each of them.

High Availability, Scalability, And Computing Power

3. What IaaS means and in which cases IaaS is most applicable? Give several examples.

In the most basic cloud-service model & according to the IETF (Internet Engineering Task Force), providers of IaaS offer computers – physical or (more often) virtual machines – and other resources. (A hypervisor, such as Xen, Oracle VirtualBox, KVM, VMware ESX/ESXi, or Hyper-V runs the virtual machines as guests. Pools of hypervisors within the cloud operational support-system can support large numbers of virtual machines and the ability to scale services up and down according to customers' varying requirements.) IaaS clouds often offer additional resources such as a virtual-machine disk image library, raw block storage, and file or object storage, firewalls, load balancers, IP addresses, virtual local area networks (VLANs), and software bundles. IaaS-cloud providers supply these resources on-demand from their large pools installed in data centers. For wide-area connectivity, customers can use either the Internet or carrier clouds (dedicated virtual private networks). To deploy their applications, cloud users install operating-system images and their application software on the cloud infrastructure. In this model, the cloud user patches and maintains the operating systems and the application software. Cloud providers typically bill IaaS services on a utility computing basis: cost reflects the amount of resources allocated and consumed.

4. What PaaS means and in which cases it is most applicable? Give several examples.

In the PaaS models, cloud providers deliver a computing platform, typically including operating system, programming language execution environment, database, and web server. Application developers can develop and run their software solutions on a cloud platform without the cost and complexity of buying and managing the underlying hardware and software layers. With some PaaS offers like Microsoft Azure and Google App Engine, the underlying computer and storage resources scale automatically to match application demand so that the cloud user does not have to allocate resources manually. The latter has also been proposed by an architecture aiming to facilitate real-time in cloud environments.

5. How to manage Azure Websites Service auto-scale and which metrics can be applicable for auto-scaling?

For increased performance and throughput for your web apps on Microsoft Azure, you can use the Azure Portal to scale your App Service plan from Free mode to Shared, Basic, Standard, or Premium mode.

Scaling up on Azure web apps involves two related actions: changing your App Service plan mode to a higher level of service, and configuring certain settings after you have switched to the higher level of service. Both topics are covered in this article. Higher service tiers like Standard and Premium modes offer greater robustness and flexibility in determining how your resources on Azure are used.

Changing modes and configuring them is easily done in the Scale tab of the management portal. You can scale up or down as required. These changes take only seconds to apply and affect all web apps in your App Service plan. They do not require your code to be changed or your applications to be redeployed.

Scaling to Shared or Basic mode

1. In your browser, open the Azure Portal.
2. In your web app's blade, click All settings, then click Scale, then click Upgrade from a Free plan to add instances and get better performance.

1. In the Choose your pricing tier blade, choose either Shared or a Basic mode, then click Select.

The Notifications tab will flash a green SUCCESS once the operation is complete.

1. Slide the Instance bar from left to right to increase the number of instances, then click Save in the command bar. The instance size option is not available in Shared mode.

The Notifications tab will flash a green SUCCESS once the operation is complete.

Scaling to Standard or Premium mode

1. To scale to Standard or Premium mode, follow the same initial steps as when scaling to Shared or Basic, and then choose a Standard or Premium mode in Choose your pricing tier, then click Select.

The Notifications tab will flash a green SUCCESS once the operation is complete, and Autoscale Mode will be enabled.

You can still slide the Instance bar to manually scale to more instances, just like in Basic mode as shown above. However, here you will learn how to use Autoscale Mode.

1. In Autoscale Mode, select Performance to autoscale based on performance metrics.

1. In Instance Range, move the two sliders to define the minimum and maximum number of instances to scale automatically for the App Service plan. For this tutorial, move the maximum slider to 6 instances.
2. Click Save in the command bar.
3. Under Target Metrics, click > to configure autoscaling rules for the default metric.

You can configure autoscaling rules for different performance metrics, including CPU, memory, disk queue, HTTP queue, and data flow. Here, you will configure autoscaling for CPU percentage that does the following:

• Scale up by 1 instance if CPU is above 70% in the last 10 minutes
• Scale up by 3 instances if CPU is above 90% in the last 5 minutes
• Scale down by 1 instance if CPU is below 50% in the last 30 minutes
1. Leave Metric dropdown as CPU Percentage.
2. In Scale up rules, configure the first rule by setting Condition to Greater, Threshold to 70 (%), Over past to 10 (minutes), Scale up by to 1 (instance), and Cool down to 10 (minutes).

1. Click Add Scale Up Rule, then configure the second rule by setting Condition to Greater, Threshold to 90 (%), Over past to 1 (minutes), Scale up by to 3 (instance), and Cool down to 1 (minutes).

1. In Scale down rules, configure the third rule by setting Condition to Less, Threshold to 50 (%), Over past to 30 (minutes), Scale down by to 1 (instance), and Cool down to 60 (minutes).

1. Click Save in the command bar. Your autoscale rule should now be reflected in the Scale blade.

Scaling a SQL Server Database connected to your web app

If you have one or more SQL Server databases linked to your web app (regardless of App Service plan mode), you can quickly scale them based on your needs.

1. To scale one of the linked databases, open your web app's blade in the Azure portal. In the Essentials collapsible dropdown, click the Resource group link. Then, in the Summary part of the resource group blade, clicked one of the linked databases.

1. In your linked SQL Database blade, click the Pricing tier part, select one of the tiers based on your performance requirement, and click Select.

1. You can also set up geo-replication to increase the high availability and disaster recovery capabilities of your SQL Database. To do this, click the Geo Replication part.

6. What can be backed up for Websites Service and how to manage it?

Website files, database (optional), Website settings manifest

7. Which Operating Systems can be used for Virtual Machines creating in Microsoft Azure, and what are maximum and minimum sizes of VMs allowed today (provide values)? Refer to:

https://msdn.microsoft.com/en-us/library/azure/dn197896.aspx

Дата добавления: 2015-10-24