Azure Interview Questions

Azure Interview Questions Download Azure Interview Questions PDF

Azure Interview Questions

The Azure fabric is the main core concept over here. It provides a service called the Azure Fabric Controller. It is called an operating system for the Azure. Because it handles or manages the following:

  • All roles (computing) and resources.
  • Deployment and activating services.
  • Health monitoring for all services.
  • Allocating, releasing of resources.
  • Provisioning VM, terminating, etc.
  • Updating patches for installed OS on Virtual Machine automatically.

In this case, it is generally better to have two instances of roles, and there is no need for the customer to worry about software updates for the user.

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

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.

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.

The queue is a one-type of Azure Storage, where a user can store your data as storage. Blobs are stored in a container, Entity in table and Message in Queue.

Listed below are the key concepts in the queue.

  • FIFO implementation
  • Messages are added to end of the Queue and processed from the front
  • Queues provides a good way of the Front end and Back end decoupling

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.

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.

A table is a type of Azure Storage, where one can store the data as memory storage. Blobs are stored in container and Entity in the table.

The key concepts in the table are explained below:

  •  Tables allow structure data storage
  •  There can be 0..n tables in a storage account
  •  Table store data as a collection of entities
  •  Entity have a primary key and properties as a key value pair

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.

The firewall checks access to the originating IPs from which a user may try to access the database. To configure the firewall, we need to configure a range of acceptable IP addresses upon which we try to connect to the SQL Azure server using the Management Portal or with the SQL Server Management Studio. All access to SQL Azure is blocked by a firewall.

By default Database created in SQL Azure is blocked by the firewall for maximized security. SQL Azure firewall rules are provided to protect the data and to prevent access restrictions to the SQL Azure database.

The Traffic Manager allows users to control the distribution of user traffic of deployed Azure cloud services, Azure websites or any other endpoint. In this, the distribution of traffic includes Azure cloud services, Azure websites, and other endpoints. There are three different load-balancing methods provided by Azure. The Traffic Manager applies an intelligent routing policy engine to the Domain Name Service (DNS) queries on the domain names and then maps the DNS routes to the apt instances of the required applications.

The Traffic Manager comes with many benefits for the user:

  • Increase Performance: Can increase the performance of your application that includes faster page loading and better user experience. This applies to the serving of users with the hosted service closest to them.
  • High Availability:You can use the Traffic Manager to improve application availability by enabling automatic customer traffic fail-over scenarios in the event of issues with one of your application instances.
  • No Downtime Required for Upgrade / Maintenance: Once you have configured the Traffic Manager, you don’t need downtime for application maintenance, patch purgation or complete new package deployment.
  • Quick Setup: It’s very easy to configure Azure Traffic Manager on Windows Azure portal. If you have already hosted your application on Windows Azure (a cloud service, Azure website), you can easily configure this Traffic Manager with a simple procedure (setting routing policy).

An availability set is a logical grouping of VMs that allows Azure to understand how the application for a user is built to provide redundancy and availability. It is recommended that two or more VMs be created within an availability set to provide for a highly available application and to meet the 99.95% Azure SLA. When a single VM is used with Azure Premium Storage, the Azure SLA applies for unplanned maintenance events.

A scale set is an implicit availability set with five fault domains and five update domains. Scale sets of more than 100 VMs span multiple placement groups, which are equivalent to multiple availability sets. An availability set of VMs can exist in the same virtual network as a scale set of VMs. A common configuration is to put control node VMs (which often require unique configuration) in availability set and put data nodes in the scale set.

Technical problems in Azure are called break-fix issues. It is an industry term, which refers to “work involved in supporting a technology when it fails in the normal course of its function, which requires intervention by a support organization to be restored to working order.”