Azure Interview Questions

A hybrid cloud is a mixture of internal and external cloud services, a combination of a private cloud combined with the use of public cloud services. This type of cloud is most suitable when you want to keep the confidential data in your premise (private cloud) and consume the other services from a public cloud.

Advantages of Hybrid Cloud:

• Scalability: Usually the Private Cloud services will have a lesser scalability due to its security, cost and compliance whereas the Public Cloud has a high scalability and moving non-sensitive data from the private to the public will free up resources in the data centers in the Private Cloud and that increases a very high scalability for a Hybrid Cloud.
• Cost-effectiveness: Similarly the Public Cloud is very cost effective rather than Private Cloud, and here the Hybrid Cloud provides cost effectiveness with the data and other sensitive operations secured.
• Security: Since there is a Private Cloud used; the data and sensitive operations are secured highly in the Hybrid Cloud.
• Flexibility: We can easily move out of the non-sensitive data and manage large scalability using a Public Cloud service along with the Private Cloud. So with the availability of large scalability using Public Cloud and security using Private Cloud an enterprise has a vast opportunity in developing for new needs.

Roles are simply servers in layman terms. They are managed and load balanced platforms like service virtual machines, which work together to achieve a common goal. There are three roles, which are implemented in Windows Azure:

• Web Role: It gives a web solution that is completely front-end. This is similar to an ASP.NET application. When it is enabled, Azure gives IIS and required services.
• Worker Role: It gives us solutions to all background service.  It can easily run long activities as well.
• Virtual Machine Role: The virtual machines execute the roles of both, web and worker. The Virtual Machine Roles gives the consumer the ability to modify the virtual machine on which the web and worker roles are running.

Private clouds are those that are built solely for an individual enterprise. They enable any particular firm to have applications in the cloud while tending to concerns concerning data security and control that is frequently ailing in a public cloud environment. It is otherwise called an internal cloud or enterprise cloud and dwells on the organization’s intranet or hosted data center where the data is protected. Public cloud is utilized as a service through the Internet by the users, while a private cloud, is implemented within specific limits like firewall settings and is overseen and checked by the users dealing with it in an organization.

For configuring with Node.Js, a user can specify the PM2 configuration file or your script file. In case of .NET Core, the user can specify their compiled DLL name. Moreover, in case of Ruby, one can specify the Ruby script that they want to initialize their app with.

Virtual machine scale sets are Azure compute resources, which can be used to deploy as well as manage a set of identical VMs. When all the VMs are configured in the same way, scale sets are automatically designed to support true auto-scale, and no pre-provisioning or prearrangement of VMs is required. That is why it is easier to build large-scale services, which target big compute, big data, and containerized workloads.

Service Fabric enables the user to build applications that comprise micro services. Stateless micro-services (like protocol gateways and web proxies) don’t maintain a mutable state outside a request and its response from the service. Examples of a stateless service include Azure Cloud Services worker roles. Stateful micro-services (like user accounts, databases, devices, shopping carts, and queues) maintain a mutable, authoritative state beyond the request and its response, unlike Stateless Services. Today’s Internet-scale applications comprise a combination of stateless as well as stateful micro-services.

The SLA ensures that, when you send two or more role instances for each role, access to your cloud service will be maintained not less than 99.95 percent of the time. Furthermore, identification and re-correction activity will be started 99.9 percent of the time when the procedure of a role instance is not running.

Storage keys, which are also known as Access Keys, are used as an authentication mode for accessing the storage services account to manipulate information based on our requirements. In Windows Azure, the users have an option to provide a Primary Access Key and a Secondary Access Key, even though it is likely that they will use a single access key to authenticate their application to the storage.

Windows Azure provides platform and infrastructure by providing accessible and cost-effective computing, storage, and networking resources on demand.

The Windows Azure has three main components in Azure, namely compute, storage and fabric.

Windows Azure Compute

Windows Azure provides a hosting environment for managed code. It provides a computation service through roles. Windows Azure supports three types of roles:

• Web roles used for web application programming and supported by IIS7.
• Worker roles are also used for background processing of web roles.
• Virtual Machine (VM) roles are generally used for migrating windows server applications to Windows Azure in an easy way.

Windows Azure Storage

 Windows Azure provides storage in the cloud. It provides four different types of storage services:

• Queues for messaging between web roles and worker roles.
• Tables for storing structural data.
• BLOBs (Binary Large Objects) to store text, files or large data.
• Windows Azure Drives (VHD) to mount a page blob. They can easily be downloaded and uploaded via blobs.

Windows Azure AppFabric

AppFabric provides infrastructure services for developing, deploying and managing Windows Azure application. It provides five services:

• Service bus
• Access
• Caching
• Integration
• Composite

Azure Queues provides the user with a solid, diligent messaging between and within the services. It also highlights quite a straightforward rest-based get/peek/put interface. The Azure Storage Queues make use of the local Azure Storage Emulator and debugging is made quite easy. The tooling for Azure Storage Queues allows you to easily peek at the top 32 messages and if the messages are in XML or JSON, one can visualize their contents directly from Visual Studio. Moreover, these queues can be purged of their contents, which is especially useful during development and QA efforts.

On the other hand, Bus Queues are part of a more far-reaching Windows Azure messaging framework, which supports queuing. As a rule, Azure Service Bus Queues can delete themselves after a configurable amount of idle time. This feature is very practical when you create Queues for each user because if a user hasn’t interacted with a Queue for the past month, it automatically gets clean it up. It is also a great way to reduce costs. However, these Queues are limited to a maximum of 80 GB. Once the user has reached this limit, his or her application will start receiving exceptions.

Azure App Service is a completely managed Platform as a Service (PaaS) offering for proficient developers that conveys a rich arrangement of abilities to the web, mobile and integration scenarios. They offer a very adaptable, universally accessible mobile application development platform for Enterprise Developers and System Integrators that conveys a rich set of capacities to mobile engineers.

VNet is a representation of your network in the cloud. It logically isolates the instances launched in the cloud, from the rest of the resources of a user.

If a user needs to change the application access key by regenerating the access key, it takes much time to take effect; this provides a downtime. To avoid such types of situations, a secondary access key is provided so that if the primary needs to be changed or regenerated, we can map the secondary temporarily to the storage and regenerate the primary.

Federation is introduced in SQL Azure for scalability. It helps administrators by making repartitioning and redistributing of data easier and thus, helps with scaling data. It helps developers in the routing layer and the sharding of data. It helps in routing without application downtime. Federation does basic scaling of objects in a SQL Azure Database. Federations are the partitioned data. There can be multiple Federations within a database. Moreover, each Federation represents a different distribution scheme. We create a Federation with a different distribution scheme and requirement. Student and Grade’s tables of a School Database may have a different distribution requirement, so they are put into different Federations.

Windows Azure Diagnostics provides facility to store diagnostics data. Some diagnostics data is stored in a table, while some are stored in a blob. For collecting the data on diagnostics, the user must initialize the Windows Azure diagnostic monitor. The Windows Azure diagnostic monitor runs in Windows Azure as well as in the computer’s emulator and collects diagnostic data for a role instance.