First set of cloud based interview questions, primarily focusing on Microsoft Azure:
1. What is cloud computing.?
A. The technology in which computer resources are provided as a service over internet to end users is termed as cloud computing. This can be core, memory, storage, networking or even software such as database, operating system etc.
2. What are the main types or categories of cloud? Among those what all does Azure provide you.?
A. Three main categories:
IAAS – Infrastructure As A Service
PAAS – Platform As A Service
SAAS – Software As A Service
Azure provides the first two categories – IAAS, PAAS to their end users.
3. What are the benefits of cloud.?
A. 1. Pay for what you use – Pay for those services that you’ve used and not for everything. Pay per hour is the model that almost all cloud providers use, Azure plans to come up with Pay per minute option soon.
2. Highly scalable – Create even 1000 servers within minutes.
3. No Cap-Ex – Eliminates capital expenditure, only requires operational expenditure.
4. Quick DR – Disaster Recovery can be very fast at low cost.
4. What is the difference between Azure VM and Azure Instance.?
A. Azure VM provides you with the entire virtual machine, where you can decide the OS, patches or updates etc. It is just that your have control on your own machine, but it resides on MS datacenter.
Azure Instances comes within the cloud service, where you only worry about the application within it and other tasks such as OS, patching/updating etc will be taken care by MS. Instances are more suited if you’ve a web application.
5. What are the role types of Azure cloud service instances?
A. Two roles are:
Web role – where the front end code of your application will reside. It has IIS running inside it.
Worker role – where the core code (for your service) runs. It doesn’t has IIS.
6. How the application is moved to Azure cloud service?
A. Three main file types used are:
.csdef – cs definition file defining service models as well as the number of roles
.cscfg – cs configuration file defining configuration settings as well as the number of role instances
.cspkg – cs package file, containing the application code as well as the csdef file
The application can be pushed to Azure manually (by clicking upload button in cloud services page in Azure portal) or can be done using some continuous integration tool like TeamCity.
7. What is a storage? What are the types in Azure.?
A. Storage normally means some space where the user can store data. Basically almost all cloud services provides you with 2 different classes of storage, one which termed as storage itself another with the name database.
Storage normally would be an object based storage where the user can store image, video or any such contents. Databases would be the area to store the data in table like structure.
In Azure, storage is again divided into 4 as:
Blob – For storing unstructured data such as documents or media files.
Queues – Messaging store for workflow processing.
Tables – For structured no-sql based data.
Files – New service, shared storage for apps using the SMB protocol.
8. How can I add extra hard disk space in my Azure VM.?
A. By default using Azure management portal you can’t do this. There are some third party tools like CloudXplorer, which will help you to extend your hard disk space. Or yes, if your hard disk is small enough (in used space) and if you’ve a good internet connection, you can get the hard disk downloaded, extend using Hyper-V manager snap in and upload it to Azure.
9. What are Blobs, Tables, Queues and Files in Azure.
A. Answered in question # 7.
10. How does Azure pricing differ for Azure VM hard disk and Azure Blob Storage.?
A. Azure VM hard disk is a .vhd file backed by a Page Blobs. You are allowed to create a hard disk of size 1 TB maximum (as of 14-May-2015), but MS costs you for how much data stored in that page blob. Which means even if you’ve 1 TB page blob and you store just 2 GB of data, then you’re charged for 2 GB rather than for 1 TB.
Azure blob storage uses Block Blobs. The maximum size of a block blob is 200 GB (as of 14-May-2015). Even if you store just 2 GB of data in your 5 GB allocated space, you’re charged for the entire 5 GB.