Top 20 Azure Interview Questions & Answers

Ques: 1. What are the sizes of the Azure VM?

Ans: It is another basic question that finds its place in the series of top Microsoft Azure interview questions. The Windows Azure is destined to balance a variety of sizes. Most of the VM sizes are:

• The extra-large computer has 8*1.6 GHz of Instance size, with instance storage of 2040 GB, CPU memory of 14 GB. The I/O performance is high. 
• The large computer has 4*1.6 GHz of Instance size, with instance storage of 1000 GB, CPU memory of 7 GB. The I/O performance is high. 
• The medium computer has 2*1.6 GHz of Instance size, with instance storage of 490 GB, CPU memory of 3.5 GB. The I/O performance is high. 
• Small computer has 1.6 GHz of Instance size, with instance storage of 225 GB, CPU memory of 1.75 GB. The I/O performance is moderate. 
• The extra small computer has 1.0 GHz of Instance size of 20 GB, with instance storage of 20 GB, CPU memory of 768MB. The I/O performance is low.

Ques: 2. How is Azure Resource Manager beneficial over the classic services?

Ans: The benefits of the Azure Resource Manager that overshadows the benefit of the classic services are:

• The resources need not be managed, deployed or monitored one at a time. They are chain deployment activities throughout the life cycle without the need for individual data handling. 
• The data is also deployed at a consistent pace with the ARM service. It enables the user to use a declarative template that indicates the deployment. 
• Since the role-based control is present in the management platform that provides you with the access to the resources that leads you to control. 
• You can mark dependencies between the resources that enable you to get the correct order of deployment. 
• The resources may be tagged and organized logically so that it is convenient to follow up the billing of your company.

Ques: 3. What do you mean by SAS?

Ans: This is one of the common SQL Azure interview questions that should be answered by stating that SAS is an abbreviation for Statistical analytical System which is a software suite performing analysis of multiple variables. It is in linked to the predictive analysis, data handling, advanced analytics or cooperative intelligence. It produces a smooth interface that offers graphical and clicks based solution. It is user-friendly for the technical or the non-technical with advanced features.

Ques: 4. Describe the log analytics?

Ans: This question can be asked among the SQL Azure interview questions. The operational management service of the Log Analytics provides the entire requirement that runs the particular service. It manifests automation, security, log analytics and availability at a particular dashboard. It generates Power data source that enables the user to get the visuals of the raw data. It is introduced in three different tiers of prices that include free, premium and standard. You enjoy the convenience of searching the data at a single dashboard and export the results.

Ques: 5. State what will you do in case of a drive failure?

Ans: This is one of another Microsoft Azure interview questions for experienced that should be answered in the following manner. When there is an instance that the drive has failed the following step should be performed:

• The first is that the drive should be not mounted enabling the object storage to function without fail. 
• The second scenario is replacing the drive in which the desired step will be remounting, formatting the drive.

Ques: 6. Give a clear overview of API in Azure?

Ans: The Test Analytics in API is a web service that is built with the Azure learning. It is an effective tool to analyze the unstructured data like the extraction of the key phrase. It runs with the binomial scoring unit that is either 0 or 1 where 1 corresponds to a positive and 0 corresponds to a negative viewpoint. The advantage is that it does not need any assistance with designing and training which imply that the data is in the hands of directly the user. Proceed to find more Microsoft Azure interview questions for experienced.

Ques: 7. Differentiate between the PROC SUMMARY and PROC MEANS?

Ans:

PROC MEANS refers to the subgroup statist created in the persistence of the BY statement that will be involved. The data here is sorted beforehand with the assistance of BY variables.

PROC SUMMARY is the aid of statistics giving all varieties of information running simultaneously and is produced for every subgroup automatically. The information in the outlet is not created.

Ques: 8. If the client gets disconnected from cache with the services state the probable cause?

Ans: If the client gets disconnected the causal factor can be distributed into two categories:

The cause on the operator side: 

• There might be a failure in the transfer of the standard cache from one node to the other. 
• While the service was processing and dispatching the cache got deployed. 
• There was a server update or an automated VM maintenance.

The fault on the client side:

• The application of the client accidentally got redeployed. 
• The application on the client side got auto-scaling. 
• The layer of the network on the client side altered. 
• There was a transient error on the network node. 
• The bound operation took more time. 
• The upper limit of the bandwidth was reached.

Ques: 9. What is purpose of cloud service configuration file (.cscfg)?  

Ans: Every cloud service type of project contains .cscfg file and primarily is used for storing.

• Number of role instances to deploy for each role in cloud service project. 
• Thumbprint of certificates used if any. 
• And most important, User defined configuration settings.

The primary aim or purpose of this file is to allow configuration changes in production environment without downtime of your application.

Ques: 10. What are different types of Azure blobs and difference between them?

Ans: Azure storage has two type of blob – Block and Page.

BLOCK BLOB:

1. Block blob is ideal for sequential read, write operations.

2. Block blobs should be natural choice for storing the various types of files such as office file, pdf, mp3, video, byte array and so on.

3. The data constitutes from various blocks and each block can have max size of 4MB.

4. Write made to block blob using PutBlock is uncommitted and maintained only for 7 days. User have to call PutBlockList to commit the data permanently.

PAGE BLOB:

1. Page blob is ideal for random read, write operations.

2. Page blob being “sparse” type of storage, is natural choice for storing .VHD files backing the Azure Virtual Machines

3. The data constitutes of various page ranges and each page should be in multiple of 512 bytes.

4. Write made to page blob using PutPage is a direct commit.

Ques: 11. What is the difference between Table Storage and SQL Azure Table?

Ans:

TABLE STORAGE: 

1. This is NoSQL store on Azure

2. As NoSQL, the data is stored in Key-Value pair combination and data is referred as an Entity.

3. Schema is not enforced while storing the data.

4. Combination of partition and row key is treated as unique for an entity.

5. Can’t have relationship between tables.

6. Being key-value store, we can’t define objects such as Stored procedures, Views, functions.

7. General usage is observed for storing diagnostics information, error log information.

SQL AZURE TABLE

1. This is relational store on Azure

2. The data is stored in Rows and Columns combination.

3. Schema is enforces while storing the data. If schema is violated, then error is thrown.  

4. User can define various constraints such primary key, unique key.

5. We can define relationships between tables such as foreign key.

6. We can created Stored procedures, views, functions.

7. Used widely in transaction based systems.

Ques: 12. What are the other VNET options for achieving connectivity with on premise and azure resources?

Ans: Site to Site and express route are other options for achieving cross premises connectivity. Site to site to specifically use when you have large number of resources to be connected. In some cases, Site to Site or Point to Site connectivity may introduce network latency as VPN created by these features work on public infrastructure (Internet) only. To overcome on this situation “Express Route” option can be taken which offers dedicated Leased Line based offering to overcome on latency issue.

Ques: 13. On premises application running few windows services, console applications to handle certain tasks. What should be the approach for migration of such applications to Azure?

Ans: There are 3 ways by which we can achieve background process migration to Azure:

1.Azure Virtual Machine  

2.Worker role 

3.Azure Web Jobs

Ques:14. What is HDInsight in Microsoft Azure?

Ans: HDInsight is a could service which that makes it easy. It is fast and cost-effective to process a massive amount of data using with the help of open-source frameworks like Spark, Hadoop, Hive, Storm and R. HDInsight offers various type of scenarios which includes ETL, data warehousing, and Machine Learning.

Ques: 15. What are the important drawbacks of using Microsoft Azure?

Ans: The below are the major drawbacks of using Azure:

• Cloud computing is not possible if you are not able to connect to the Internet.
• Azure is a web-based app which needs a lot of bandwidth to download, as do large documents. 
• Web-based applications can sometimes be slower compared accessing similar software program on your desktop PC.

Ques: 16. What are the main benefits of Traffic Manager?

Ans: Traffic management offers many advantages for the user:

• Increase the performance. 
• No Downtime required for update or Maintenance. 
• You can easily configure Azure Traffic manager on Windows Azure portal.

Ques: 17. State the difference pricing model of Microsoft Azure.

Ans: The different pricing model of Microsoft Azure are:

BYOL Model: It brings your license model. It is just right to access model. You can obtain it outside of the Azure Marketplace. This model is not charged any fees.

Free Software Trial: It is a full-featured version which is promotionally free for a limited period of time. However, for excessive use, you need to pay fees.

Usage-based: This is a widely used model of Microsoft Azure. Here, user are changed for only that service which is used by them.

Monthly fee: Here, you need to pay a fixed monthly payment for a subscription.

Ques: 18. How can you categorizes Azure services?

Ans: Azure services are classified into into 11 types:

1. Compute 
2. Web 
3. Mobile 
4. Data storage 
5. Analytics Networking 
6. Media 
7. Content Delivery Network (CDN) 
8. Hybrid integration 
9. Identity and access management (IAM) 
10. Internet of Things (IoT) 
11. Development Management and security 

Ques:19. What is Azure Service Fabric?

Ans: Azure Service Fabric is a distributed platform for deploying and managing microservices and containers. It allows the developers to focus on implementation which is scalable, reliable, and manageable and not be concerned about the infrastructure. It uses the Azure Service Fabric Resource Provider.

It allows developers to build applications which are composed of micro services. These services run on pool of Virtual machines known as a cluster.
It allows the services to massively scale out. You can create clusters for Service Fabric in many environments such as Linux, on premise. The microservices you can build with Service Fabric can be stateful or stateless.

Ques: 20. What is Service Bus?

Ans: Service bus is a messaging service in Azure.You can use Service bus for sending messages between applications.It is used for decoupling applications and provides asynchronous communication using queues.

Top 20 Node.js Interview Questions and Answers

               Preparing for the Node js interview questions, you should start with the basic concepts to advanced topics and move up from down. It is important to understand how things work before moving on the more complex topics. To get the best understanding of Node.js, you must have a basic understanding of JavaScript related concepts as well.

 

Ques: 1. What can be the possible use of DNS module in Node.js?

Answer:

This is one of the most asked Node js interview questions. The DNS module consists of an asynchronous network wrapper. Let’s have a look at the most commonly used functions of this module:

1. DNS.lookup(address, options, callback) – This method takes any website’s address as its first parameter and returns the corresponding first IPV4 or IPV6 record. The options parameter can be an integer or object. If no options are provided both IPV4 and IPV6 are valid inputs. The third parameter is the callback functions.

2. DNS.lookupservice(address, port, callback) – This function converts any physical address to an array of record types. The record types are specified by the second parameter, rrbyte. The third method is the callback function.

3. dns.getServers() – This function returns an array of IP address strings that are currently configured for DNS resolution, formatted according to rfc5952. A string will include a port section if a custom port is used.

4. DNS.setServers() – This function sets the IP address and port of servers to be used when performing DNS resolution. The DNS.setServers() method must not be called while a DNS query is in progress.

AngularJS Interview Questions and Answers

Ques: 2. How can you use Timers in Node.js?

Answer:

As the name suggests, the Timer module executes code after a set period of time. It doesn’t need to be imported via require(). All the methods are available globally to emulate the browser JavaScript API which provides several ways of scheduling code to execute at a certain time.

The functions provided by Node.js for Timers are:

setTimeout(), setImmediate(), and setInterval.

AJAX interview Questions and Answers

Ques: 3. What do you mean by non-blocking mean in Node.js?

Answer:

If you are talking about non-blocking in Node.js, you are much aware about the non-blocking I/O.  It can be explained how Node uses libuv to handle its IO in a platform-agnostic way. A non-blocking request is made and upon a request, it queues it within the event loop. The JavaScript callback is then called on the main JavaScript thread.

JavaScript Interview Questions and Answers

Ques: 4. What is the main difference between Node.js and Ajex?

Answer:

The easiest way to explain the difference between Node.js and Ajax is that Node is a server-side JavaScript, while Ajax is a client-side technology. What that means is that Ajax is often used for updating the contents of the page without refreshing it. Node, on the other hand, is used for developing server software, executed by the server rather than in the browser.

JQuery Interview Questions and Answers

Ques: 5. What are the various pros and cons of Node.js?

Answer:

Let’s take a look at the most important pros and cons:

Pros: 

• In the cases when your app doesn’t have any CPU intensive computation, you can build the whole thing in Javascript, including the basic database level. All you have to do is use  JSON storage object DB like MongoDB. 
• Crawlers receive a full-rendered HTML response which is great for SEO.

Cons: 

• Node.js responsiveness is blocked by an intensive CPU computation so a threaded platform would a better approach in those cases. 
• Using a relational database with Node.js is considered less favourable.

Advance Java interview Questions and Answers

Ques: 6. What is the use of method spawn() and fork()?

Answer:

The spawn method is used when a new process is to be launched with a given set of commands. Check out the following command:

child_process.spawn(command[, args][, options])

The fork method is considered to be a special case for spawn() method. The following code shows how to use it:

child_process.fork(modulePath[, args][, options])

Ques: 7. Can you explain the EventEmitter in Node.js?

Answer:

EventMitter class for event module helps with raising and handling custom events. You can access it with the following code:

// Import events module

var events = require(‘events’);

// Create an eventEmitter object

var eventEmitter = new events.EventEmitter();

Ques: 8. What do you understand by tracing?

Answer:

The purpose of tracing is to trace information generated by V8. To enable it, pass flag-trace-events-enabled when starting the node.

All recorded categories can be specified by the flag–trace-event categories. The enabled logs can be opened as chrome://tracing in Chrome.

 

Ques: 9. Can you explain the control flow function and steps to execute it?

Answer:

The control flow function is the code that runs between asynchronous function calls. Following steps should be followed to execute it: 

1. Control the order of execution. 
2. Collect data. 
3. Limit concurrency. 
4. Call the next step in the program.

 

Ques: 10. What is the file system module of Node js?

Answer:

The file system module performs a file-related operation. It comprises synchronous and asynchronous functions to read/write files.

For instance, readFile() function is asynchronous function to read file content from specified path and readFileSync() is synchronous function to read files.

 

Ques: 11. What are some of the most popular modules of Node.js?

Answer:

The most popular modules Nodes.js are:

• xpress 
• async 
• browserify 
• socket.io 
• bower 
• gulp 
• grunt

 

Ques: 12. What do you understand by package.json in node.js? What is it used for?

Answer:

Package.json holds various metadata information about the project. The information contained in this file is then given to npm to identify the project and to handle its dependencies.  

Some of the fields are name, description, author, and dependencies.

The dependencies are then installed whenever the project is installed through npm. Moreover, if the npm install is run in the root directory of the project, the dependencies will be installed in ./node_modules directory.

 

Ques: 13. What is the difference between Asynchronous and Non-blocking?

Answer:

Asynchronous or simply not synchronous means that the HTTP requests are not waiting for the server response. You can continue with other block and respond to the server response when received.

Non-Blocking, on the other hand, is a term commonly used with IO. For instance, non-blocking read/write calls return and expect the caller to call again. Read will wait until it has some data and put calling thread to sleep.

Ques: 14. What are the features of Node.js?

Answer:

Since the APIs of Node.js library are asynchronous, they are non-blocking which means that a Node.js based server never waits for an API to return data. Node.js is a system built on Google Chrome’s V8 JavaScript Engine which makes it very fast.

This system uses a single threaded model with event looping. With the event mechanism helping the server respond in a non-blocking way, the server is highly scalable compared to the other servers that create limited threads to handle requests.

 

Ques: 15. Why should you use Node.js?

Answer:

One could use Node.js when they want to easily build scalable apps. The biggest pros include:

• It is very fast in code execution.
• It is asynchronous and event-driven.
• It is single-threaded but highly scalable.
• No buffering.

Ques: 16. Explain the role of REPL in Node.js.?

Answer:

REPL stands for Read, Evaluate, Print, Loop – and it performs all the mentioned tasks accordingly. It is used to execute ad-hoc JavaScript statements and it is a very important part of the testing and debugging process.

 

Ques: 17. What is libuv library? And what is its use in Node.js?

Answer:

Libuv is a multi-platform support library with a focus on asynchronous I/O. Although it was primarily developed for Node.js, it’s also commonly used by other systems such as Luvit, Julia, pyuv etc.

Back in the days when the whole Node project started, it was using Google’s V8 and Marc Lehmann’s libev. However, the problem with libev was that it ran only on Unix so they had to come up with the new solution to make it work on Windows, especially once node.js grew in popularity.

Libuv was an abstraction around libev or IOCP depending on the platform, providing users an API based on libev. In the node-v0.9.0 version of libuv, libev was removed.

Here are some of the key features:

• Full-featured event loop backed by epoll, kqueue, IOCP, event ports. 
• Asynchronous TCP and UDP sockets. 
• Asynchronous file and file system operations.
• Child processes.
• File system events.

Ques: 18. What are the two arguments that async.queue takes?

Answer:

These two arguments are:

a)      Task function

b)      Concurrency value

 

Ques: 19. How to avoid Callback Hell?

Answer:

Basically, every time a long-running query finishes its execution, the callback associated with the query is run. Since Node.js uses single thread only, it happens that it leads to numerous queued events. And that is where the callback comes in.

There are 4 common solutions for this issue:

Modular code – the code split into smaller modules that are later joined together to the main module again

Promise mechanism – ensures either a result or error; it’s an alternative way for the async code and it takes two optional arguments, one of which is called depending on the state of promise

Use of generators – they wait and resume using the yield keyword but can also suspend and resume async operations.

Async mechanism – the module with <async.waterfall> API which passes data from one operation to another using the next callback.

 

Ques: 20. What isNPM?

Answer:

NPM stands for Node Package Manager. It has 2 important functions:

It works on Online Repository for node.ls packages which are present at <nodejs.org>. In addition to that, it also works as a command line utility and does version management.

You can verify version using below command: npm –version.

To install any module you can use: npm install <Module Name>

Top 20 Unix interview Questions & Answers

Ques: 1. What is the Importance of writing Shell Scripts?

Ans: The points given below explain the importance of writing shell scripts. Shell script takes input from the user, file and displays it on the screen. Shell scripting is very useful in creating your own commands. It is helpful in automating some tasks of the day to day life. It is useful for automating system administration tasks. Mainly it saves time.


Ques: 2. What are the different Types of Shells available? 

Ans: There are mainly 4 important types of shells that are widely used. And they include:

1. Bourne Shell (sh)
2. C Shell (csh)
3. Korn Shell (ksh)
4. Bourne Again Shell (bash)

Ques: 3. What are the Advantages of C Shell over Bourne Shell?

Ans: The advantages of C Shell over Bourne Shell are:

• C shell allows aliasing of commands i.e. a user can give any name of his choice to the command. This feature is mainly useful when a user has to type the lengthy command again and again. At that point of time, instead of typing a lengthy command a user can type the name that he has given.
• C shell provides command history feature. C shell remembers the previously typed command. Thus, it avoids typing the command again and again.

Ques: 4. What are the two types of Shell Variables? Explain in brief.

Ans: The two types of shell variables are: 

1). Unix Defined Variables or System Variables – These are standard or shell defined variables. Generally, they are defined in CAPITAL letters. 

for example: SHELL – This is a Unix Defined or System Variable, which defines the name of the default working shell. 

2). User Defined Variables – These are defined by users. Generally, they are defined in lower letters. 

For example: $ a=10 –Here the user has defined a variable called ‘a’ and assigned value to it as 10.

Ques:5. What are positional parameters? Explain with an example.

Ans: Positional parameters are the variables defined by a shell. And they are used whenever we need to convey information to the program. And this can be done by specifying arguments at the command line.

There are totally 9 positional parameters present i.e. from $1 to $9.

Example: $ Test Indian IT Industry has grown very much faster

In the above statement, positional parameters are assigned like this.

$0 -> Test (Name of a shell program/script)

$1 ->Indian

$2 -> IT and so on.

Ques: 6. What are the three different security provisions provided by UNIX for a file or data?

Ans: Three different security provisions provided by UNIX for a file or data are:

1. It provides a unique user id and password to the user, so that unknown or unauthorized person should not be able to access it.
2. At file level, it provides security by providing read, write & execute permissions for accessing the files.
3. Lastly, it provides security using file encryption. This method allows encoding a file in an unreadable format. Even if someone succeeds in opening a file, but they cannot read its contents until and unless it is decrypted.

Ques: 7. What are control instructions and how many types of control instructions are available in a shell? Explain in brief.

Ans: Control Instructions are the ones, which enable us to specify the order in which the various instructions in a program/script are to be executed by the computer. Basically, they determine a flow of control in a program.

There are 4 types of control instructions that are available in a shell:

1. Sequence Control Instruction – This ensures that the instructions are executed in the same order in which they appear in the program.
2. Selection or Decision Control Instruction – It allows the computer to take a decision as to which instruction is to be executed next. 
3. Repetition or Loop Control Instruction – It helps a computer to execute a group of statements repeatedly. 
4. Case-Control Instruction – This is used when we need to select from several alternatives.

Ques: 8. What are the two files of crontab command?

Ans: Two files of crontab command are:

1. cron.allow – It decides which users need to be permitted from using crontab command. 
2. cron.deny – It decides which users need to be prevented from using crontab command.

Ques: 9. What are the different commands available to check the disk usage?

Ans: There are three different commands available to check the disk usage. And they are:

1. df – This command is used to check the free disk space.  
2. du – This command is used to check the directory wise disk usage.  
3. dfspace – This command is used to check the free disk space in terms of MB.

Ques: 10. What is Shebang in a shell script?

Ans: Shebang is a # sign followed by an exclamation i.e. !. Generally, this can be seen at the beginning or top of the script/program. Usually, a developer uses this to avoid repetitive work. Shebang mainly determines the location of the engine which is to be used in order to execute the script.

Here ‘#’ symbol is called as hash and ‘!’ is called a bang.

Example: #!/bin/bash

The above line also tells which shell to use.

Ques: 11. What is inode?

Ans. The inode is a data structure in a file system. Each inode is able to store the attributes and the location (s) of the disk block of the object’s data.

Ques: 12. What is the difference between Swapping and Paging?

Ans:

Swapping: Whole process is moved from the swap device to the main memory for execution. Process size must be less than or equal to the available main memory. It is easier to implementation and overhead to the system. Swapping systems does not handle the memory more flexibly as compared to the paging systems.

Paging: Only the required memory pages are moved to main memory from the swap device for execution. Process size does not matter. Gives the concept of the virtual memory. It provides greater flexibility in mapping the virtual address space into the physical memory of the machine. Allows more number of processes to fit in the main memory simultaneously. Allows the greater process size than the available physical memory. Demand paging systems handle the memory more flexibly.

Ques: 13. What is the difference between $* and $@?

Ans: $@ treats each quoted argument as separate arguments but $* will consider the entire set of positional parameters as a single string.

Ques: 14. Write down syntax for all loops in shell scripting ?

Ans: The syntax for all loops in unix:

for loop:

for i in $( ls ); do
echo item: $i
done

while loop:

#!/bin/bash
COUNTER=0
while [ $COUNTER -lt 10 ]; do
echo The counter is $COUNTER
let COUNTER=COUNTER+1
done

until loop:

#!/bin/bash
COUNTER=20
until [ $COUNTER -lt 10 ]; do
echo COUNTER $COUNTER
let COUNTER-=1
done

Ques: 15. Can you link directories to hard links?

Ans: You cannot link directories to hard links and the reason behind it is quite technical. For now, you can learn that directories don’t fit into the system and essentially break it. So, in order to protect the file system structure, directories are avoided link with hard links.

Ques: 16. What are the security provisions provided by the Unix to protect the system?

Ans: In order to protect valuable information and files, Unix provides three key security provisions:

1. It provides a unique ID and password to its every user so; no unauthorized access can be granted to anyone. 
2. On each file, it offers read, writes and execute permission so, the user can grant permission he or she thinks is necessary to the third party. 
3. Lastly the Unix offers security through the encryption which is one of the best ways to secure your file and data.

Ques: 17. Write down modes of operations in Vi editors and describe them?

Ans: Three significant modes of operation Vi include:

• Insert mode: this mode will allow you to insert edit the existing text or add the new text in the command line. 
• Command mode: in this mode, you can use the keyboard to make all the commands. 
• The ex-command mode: with this mode, you can enter the command in the command line.

Ques: 18. If one process is inserting data into your MySQL database? How will you check how many rows inserted into every second?

Ans: Purpose of this Unix Command Interview is asking about "watch" command in UNIX which is repeatedly execute command provided with specified delay.

Ques: 19. What is break statement why do we use it?

Ans: The break refers to the command that is used whenever the user wants to directly jump out of the loop rather than following the path which leads back to the control command. Every single time break statement takes place in the program, the control automatically gets passed after the first line of command.

Ques 20: How will you run a process in background? How will you bring that into foreground and how will you kill that process?

Ans: For running a process in background use "&" in command line. For bringing it back in foreground use command "fg jobid" and for getting job id you use command "jobs", for killing that process find PID and use kill -9 PID command. This is indeed a good Unix Command interview questions because many of programmer not familiar with background process in UNIX.