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Jenkins interview Questions

Jenkins Interview Questions

Just commit changes to the SCR (Source Code Repository) and Jenkins can automate
the rest of the process for you with the help of plugins. So that makes it a very
important DevOps tool. There is a high possibility that you encounter many Jenkins
questions if you go for a DevOps job interview. Below are the most frequently asked
Jenkins interview questions. I have collected these questions after doing a lot of
research and after discussing with some DevOps experts who are directly involved in
the hiring process. Curious to know more about Jenkins check out this Jenkins blog
This Jenkins Interview Questions blog is a part of parent blog DevOps Interview
Questions. It includes all the DevOps Stages. 
First question in this Jenkins Interview Questions blog has to be:
DevOps Interview Questions and Answers | DevOps Training |

Q1. What is Jenkins?

My suggestion is to start this answer by giving a definition of Jenkins.
Jenkins is an open source automation tool written in Java with plugins built for
Continuous Integration purpose. Jenkins is used to build and test your software projects
continuously making it easier for developers to integrate changes to the project, and
making it easier for users to obtain a fresh build. It also allows you to continuously
deliver your software by integrating with a large number of testing and deployment
Once you have defined Jenkins give an example, you can refer the below mentioned
use case:
● First, a developer commits the code to the source code repository. Meanwhile, the
Jenkins server checks the repository at regular intervals for changes.
● Soon after a commit occurs, the Jenkins server detects the changes that have
occurred in the source code repository. Jenkins will pull those changes and will
start preparing a new build.
● If the build fails, then the concerned team will be notified.
● If built is successful, then Jenkins deploys the built in the test server.
● After testing, Jenkins generates a feedback and then notifies the developers about
the build and test results.
● It will continue to check the  source code repository for changes made in the
source code and the whole process keeps on repeating.

Interviewer now knows what is Jenkins but why we use it, there are many other CI
tools as well, so why Jenkins?, the next question in this Jenkins interview questions will
deal with that answer.
Q2. What are the benefits of using Jenkins?

I will suggest you to include the following benefits of Jenkins, if you can recall any other
benefit apart from the below mentioned points you can include that as well.
● At integration stage, build failures are cached.
● For each change in the source code an automatic build report notification is
● To notify developers about build report success or failure, it is integrated with LDAP
mail server.
● Achieves continuous integration agile development and test driven development.
● With simple steps, maven release project is automated.
● Easy tracking of bugs at early stage in development environment than production.
Interviewer: Okay Jenkins looks like a really cool tool, but what are the requirements
for using Jenkins?
Q3. What are the pre-requisites for using Jenkins?

Answer to this is pretty straightforward To use Jenkins you require:
● A source code repository which is accessible, for instance, a Git repository.
● A working build script, e.g., a Maven script, checked into the repository.

Remember, you have mentioned Plugins in your previous answer, so next question in
this Jenkins interview questions blog will be regarding Plugins.
Q4. Mention some of the useful plugins in Jenkins?

Below I have mentioned some important Plugins:
● Maven 2 project
● Git
● Amazon EC2
● HTML publisher
● Copy artifact
● Join
● Green Balls

These Plugins I feel are the most useful plugins, if you want to include any other Plugin
that is not mentioned above, you can add that as well, but make sure you first mention
the above stated plugins and then add your own.
Q5. Mention what are the commands you can use to start Jenkins

For this answer I will suggest you to go with the below mentioned flow:

To start Jenkins manually open Console/Command line, then go to your Jenkins
installation directory. Over there you can use the below commands:

To start Jenkins: jenkins.exe start
To stop Jenkins: jenkins.exe stop
To restart Jenkins: jenkins.exe restart
Q6. Explain how you can set up Jenkins job?

My approach to this answer will be to first mention how to create Jenkins job.
Go to Jenkins top page, select “New Job”, then choose “Build a free-style software
Now you can tell the elements of this freestyle job:
● Optional SCM, such as CVS or Subversion where your source code resides.
● Optional triggers to control when Jenkins will perform builds.
● Some sort of build script that performs the build (ant, maven, shell script, batch
file, etc.) where the real work happens.
● Optional steps to collect information out of the build, such as archiving the artifacts
and/or recording javadoc and test results.
● Optional steps to notify other people/systems with the build result, such as sending
e-mails, IMs, updating issue tracker, etc..
Q7. Explain how to create a backup and copy files in Jenkins?

Answer to this question is really direct.
To create a backup all you need to do is to periodically back up your JENKINS_HOME
directory. This contains all of your build jobs configurations, your slave node
configurations, and your build history. To create a back-up of your Jenkins setup, just
copy this directory. You can also copy a job directory to clone or replicate a job or
rename the directory.

Learn Jenkins With DevOps Now

Q8. How will you secure Jenkins?

The way I secure Jenkins is mentioned below, if you have any other way to do it than
mention that:
● Ensure global security is on.
● Ensure that Jenkins is integrated with my company’s user directory with
appropriate plugin.
● Ensure that matrix/Project matrix is enabled to fine tune access.
● Automate the process of setting rights/privileges in Jenkins with custom version
controlled script.
● Limit physical access to Jenkins data/folders.
● Periodically run security audits on same.

I hope you have enjoyed the above set of Jenkins interview questions, the next set of
questions will be more challenging, so be prepared.
Q9 Explain how you can deploy a custom build of a core plugin?

Below are the steps to deploy a custom build of a core plugin:
● Stop Jenkins.
● Copy the custom HPI to $Jenkins_Home/plugins.
● Delete the previously expanded plugin directory.
● Make an empty file called .hpi.pinned.
● Start Jenkins.
Q10. What is the relation between Hudson and Jenkins?

You can just say Hudson was the earlier name and version of current Jenkins. After
some issue, the project name was changed from Hudson to Jenkins.
Q11. What you do when you see a broken build for your project in

There can be multiple answers to this question I will approach this task in the following
I will open the console output for the broken build and try to see if any file changes
were missed. If I am unable to find the issue that way, then I will clean and update my
local workspace to replicate the problem on my local and try to solve it.

If you do it in a different way then just mention that in your answer.
Q12. Explain how you can move or copy Jenkins from one server to

I will approach this task by copying the jobs directory from the old server to the new
one. There are multiple ways to do that, I have mentioned it below:

You can:
● Move a job from one installation of Jenkins to another by simply copying the
corresponding job directory.
● Make a copy of an existing job by making a clone of a job directory by a different
● Rename an existing job by renaming a directory. Note that if you change a job
name you will need to change any other job that tries to call the renamed job.

Q13. What are the various ways in which build can be scheduled in

You can schedule a build in Jenkins in the following ways:
● By source code management commits
● After completion of other builds
● Can be scheduled to run at specified time ( crons )
● Manual Build Requests
Q14. What is the difference between Maven, Ant and Jenkins?

Maven and Ant are Build Technologies whereas Jenkins is a continuous integration tool.
Q15. Which SCM tools Jenkins supports?

Below are Source code management tools supported by Jenkins:
● AccuRev
● CVS,
● Subversion,
● Git,
● Mercurial,
● Perforce,
● Clearcase
Now, the next set of Jenkins interview questions will test your experience with Jenkins.
Q16. What are the two components Jenkins is mainly integrated

According to me Jenkins is mainly integrated with the following:
● Version Control system like GIT,SVN.
● Build tools like Apache Maven.

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GIT Interview Questions

Q1. What is Git?

I will suggest you to attempt this question by first telling about the architecture of git
as shown in the below diagram just try to explain the diagram by saying:
Git is a Distributed Version Control system (DVCS). It can track changes to a file and
allows you to revert back to any particular change.
Its distributed architecture provides many advantages over other Version Control
Systems (VCS) like SVN one major advantage is that it does not rely on a central
server to store all the versions of a project’s files. Instead, every developer “clones” a
copy of a repository I have shown in the diagram with “Local repository” and has
the full history of the project on his hard drive so when there is a server outage all you
need for recovery is one of your teammate’s local Git repository. There is a central
cloud repository as well where developers can commit changes and share it with other
teammates as you can see in the diagram where all collaborators are commiting
changes “Remote repository”. 

Now remember, you have mentioned SVN in the previous answer, so the next question
in this Git Interview Questions blog will be related to the difference between Git and
Q2. What is the difference between Git and SVN?

The proper answer for this according to me will be the architectural differences between
Git and SVN. So the basic difference is that Git is distributed and SVN is centralized
version control system.
Then explain the same by including the below mentioned differences:

Now, the next set of Git interview questions will test your experience with Git:
Q3. What is the command to write a commit message in Git?

Answer to this is pretty straightforward.
Command that is used to write a commit message is “git commit -a”.

Now explain about -a flag by saying -a on the command line instructs git to commit the
new content of all tracked files that have been modified. Also mention you can use “git
add<file>” before git commit -a if new files need to be committed for the first time.
Q4. What is ‘bare repository’ in Git?

You are expected to tell the difference between a “working directory” and “bare
A “bare” repository in Git just contains the version control information and no working
files (no tree) and it doesn’t contain the special .git sub-directory. Instead, it contains

all the contents of the .git sub-directory directly in the main directory itself, where as
working directory consist of:  
1. A .git subdirectory with all the Git related revision history of your repo.
2. A working tree, or checked out copies of your project files.
Q5. What language is used in Git?

Instead of just telling the name of the language, you need to tell the reason for using it
as well. I will suggest you to answer this by saying:
Git uses ‘C’ language. GIT is fast, and ‘C’ language makes this possible by reducing the
overhead of run times associated with high level languages.
Learn Git With DevOps Now

Q6. In Git how do you revert a commit that has already been pushed and made

  • There can be two answers to this question and make sure that you include both
    because any of the below options can be used depending on the situation:
    Remove or fix the bad file in a new commit and push it to the remote repository.
    This is the most natural way to fix an error. Once you have made necessary
    changes to the file, commit it to the remote repository for that I will use
    git commit -m “commit message” 
  • Create a new commit that undoes all changes that were made in the bad do this I will use a command
    git revert <name of bad commit>
    Q7. What is the difference between git pull and git fetch?

Git pull command pulls new changes or commits from a particular branch from your
central repository and updates your target branch in your local repository.
Git fetch is also used for the same purpose but it works in a slightly different way.
When you perform a git fetch, it pulls all new commits from the desired branch and
stores it in a new branch in your local repository. If you want to reflect these changes in
your target branch, git fetch must be followed with a git merge. Your target branch will
only be updated after merging the target branch and fetched branch. Just to make it
easy for you, remember the equation below:

Git pull = git fetch + git merge
Q8. What is ‘staging area’ or ‘index’ in Git?

For this answer try to explain the below diagram as you can see:
That before completing the commits, it can be formatted and reviewed in an
intermediate area known as ‘Staging Area’ or ‘Index’. From the diagram it is evident
that every change is first verified in the staging area I have termed it as “stage file” and
then that change is committed to the repository.

If your interviewer has good knowledge on Git he/she will dig in deep, so the next set
of Git interview questions will be more challenging.
Q9. What is Git stash?

According to me you should first explain the need for Git stash.
Often, when you’ve been working on part of your project, things are in a messy state
and you want to switch branches for sometime to work on something else. The problem

is, you don’t want to do a commit of half-done work just so you can get back to this
point later. The answer to this issue is Git stash.
Now explain what is Git stash. 
Stashing takes your working directory that is, your modified tracked files and staged
changes and saves it on a stack of unfinished changes that you can reapply at any
Q10. What is Git stash drop?

Begin this answer by saying for what purpose we use Git ‘stash drop’.
Git ‘stash drop’ command is used to remove the stashed item. It will remove the last
added stash item by default, and it can also remove a specific item if you include it as
an argument.
Now give an example.
If you want to remove a particular stash item from the list of stashed items you can use
the below commands:
git stash list: It will display the list of stashed items like:
stash@{0}: WIP on master: 049d078 added the index file
stash@{1}: WIP on master: c264051 Revert “added file_size”
stash@{2}: WIP on master: 21d80a5 added number to log
If you want to remove an item named stash@{0} use command git stash drop
Q11. How do you find a list of files that has changed in a particular commit?

For this answer instead of just telling the command, explain what exactly this command
will do.
To get a list files that has changed in a particular commit use the below command:
git diff-tree -r {hash}

Given the commit hash, this will list all the files that were changed or added in that
commit. The -r flag makes the command list individual files, rather than collapsing
them into root directory names only.
You can also include the below mentioned point, although it is totally optional but will
help in impressing the interviewer.
The output will also include some extra information, which can be easily suppressed by
including two flags:
git diff-tree –no-commit-id –name-only -r {hash}
Here –no-commit-id will suppress the commit hashes from appearing in the output, and
–name-only will only print the file names, instead of their paths.
Q12. What is the function of ‘git config’?

First tell why we need ‘git config‘. 
Git uses your username to associate commits with an identity. The git config command
can be used to change your Git configuration, including your username.
Now explain with an example.
Suppose you want to give a username and email id to associate commit with an identity
so that you can know who has made a particular commit. For that I will use:
git config –global “Your Name”: This command will add username.
git config –global “Your E-mail Address”: This command will add email
Q13. What does commit object contains?

Commit object contains the following components, you should mention all the three
points present below:
 A set of files, representing the state of a project at a given point of time
 Reference to parent commit objects
 An SHAI name, a 40 character string that uniquely identifies the commit object.
Q14. How can you create a repository in Git?

This is probably the most frequently asked questions and answer to this is really simple.
To create a repository, create a directory for the project if it does not exist, then run
command “git init”. By running this command .git directory will be created in the
project directory.
Q15. How do you squash last N commits into a single commit?

There are two options to squash last N commits into a single commit include both of the
below mentioned options in your answer:
 If you want to write the new commit message from scratch use the following
git reset –soft HEAD~N &&
git commit
 If you want to start editing the new commit message with a concatenation of the
existing commit messages then you need to extract those messages and pass
them to Git commit for that I will use
git reset –soft HEAD~N &&
git commit –edit -m”$(git log –format=%B –reverse .HEAD@{N})”
Q16. What is Git bisect? How can you use it to determine the source of a
(regression) bug?

I will suggest you to first give a small definition of Git bisect.
Git bisect is used to find the commit that introduced a bug by using binary search.
Command for Git bisect is
git bisect <subcommand> <options>

Now since you have mentioned the command above explain them what this command
will do.
This command uses a binary search algorithm to find which commit in your project’s
history introduced a bug. You use it by first telling it a “bad” commit that is known to
contain the bug, and a “good” commit that is known to be before the bug was
introduced. Then Git bisect picks a commit between those two endpoints and asks you
whether the selected commit is “good” or “bad”. It continues narrowing down the range
until it finds the exact commit that introduced the change.

Q17. How do you configure a Git repository to run code sanity checking tools
right before making commits, and preventing them if the test fails?

I will suggest you to first give a small introduction to sanity checking.
A sanity or smoke test determines whether it is possible and reasonable to continue

Now explain how to achieve this.
This can be done with a simple script related to the pre-commit hook of the repository.
The pre-commit hook is triggered right before a commit is made, even before you are
required to enter a commit message. In this script one can run other tools, such as
linters and perform sanity checks on the changes being committed into the repository.
Finally, give an example, you can refer the below script:
files=$(git diff –cached –name-only –diff-filter=ACM | grep ‘.go$’)
if [ -z files ]; then
exit 0
unfmtd=$(gofmt -l $files)
if [ -z unfmtd ]; then
exit 0
echo “Some .go files are not fmt’d”
exit 1
This script checks to see if any .go file that is about to be committed needs to be
passed through the standard Go source code formatting tool gofmt. By exiting with a
non-zero status, the script effectively prevents the commit from being applied to the
The Interviewer has not started asking questions on branching yet, so the next set of
Git interview questions will be dealing with branching in Git.

Q18. Describe branching strategies you have used?

This question is asked to test your branching experience with Git so, tell them about
how you have used branching in your previous job and what purpose does it serves,
you can refer the below mention points:
 Feature branching
A feature branch model keeps all of the changes for a particular feature inside of
a branch. When the feature is fully tested and validated by automated tests, the
branch is then merged into master.
 Task branching
In this model each task is implemented on its own branch with the task key
included in the branch name. It is easy to see which code implements which
task, just look for the task key in the branch name.
 Release branching
Once the develop branch has acquired enough features for a release, you can
clone that branch to form a Release branch. Creating this branch starts the next
release cycle, so no new features can be added after this point, only bug fixes,
documentation generation, and other release-oriented tasks should go in this
branch. Once it is ready to ship, the release gets merged into master and tagged
with a version number. In addition, it should be merged back into develop
branch, which may have progressed since the release was initiated.

In the end tell them that branching strategies varies from one organization to another
so I know basic branching operations like delete, merge, checking out a branch etc..
Q19. How will you know in Git if a branch has already been merged into

The answer is pretty direct.
To know if a branch has been merged into master or not you can use the below
git branch –merged It lists the branches that have been merged into the current
git branch –no-merged It lists the branches that have not been merged.
Q20. What is Git rebase and how can it be used to resolve conflicts in a feature
branch before merge?

According to me you should start by saying git rebase is a command which will merge
another branch into the branch where you are currently working, and move all of the
local commits that are ahead of the rebased branch to the top of the history on that
Now, once you have defined Git rebase time for an example to show how it can be used
to resolve conflicts in a feature branch before merge.
If a feature branch was created from the master, and since then the master branch has
received new commits, Git rebase can be used to move the feature branch to the tip of
master. The command effectively will replay the changes made in the feature branch at
the tip of master, allowing conflicts to be resolved in the process. When done with care,
this will allow the feature branch to be merged into master with relative ease and
sometimes as a simple fast-forward operation.
You can also expect some off track questions, so the next question in this Git interview
questions blog will be regarding SubGit.
Q21. What is SubGit?

Begin this answer by explaining what is SubGit used for.
SubGit is a tool for SVN to Git migration. It creates a writable Git mirror of a local or
remote Subversion repository and uses both Subversion and Git as long as you like.
Now you can include some advantages like you can do a fast one-time import from
Subversion to Git or use SubGit within Atlassian Bitbucket Server.We can use SubGit to
create a bi-directional Git-SVN mirror of existing Subversion repository. You can push
to Git or commit to Subversion at your convenience. Synchronization will be done by

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Ansible Interview Questions

What is Ansible?

Ansible is a software tool to deploy an application using ssh without any downtime.It is also used to manage and configure software applications. Python language develops Ansible.
What are the Advantages of Ansible?
-Very low overhead
-Good performance
How Ansible Works?

There are many similar automation tools available like Puppet, Capistrano, Chef, Salt, Space Walk, etc, but Ansible categorizes into two types of server: controlling machines and nodes.
The controlling machine, where Ansible is installed, and Nodes are managed by this controlling machine over SSH. The location of nodes is specified by controlling the machine through its inventory.
The controlling machine (Ansible) deploys modules to nodes using SSH protocol, and these modules are stored temporarily on remote nodes and communicate with the Ansible machine through a JSON connection over the standard output.

Ansible is agent-less, that means no need for any agent installation on remote nodes, so it means there are no any background daemons or programs are executing for Ansible when it’s not managing any nodes.
Ansible can handle 100’s of nodes from a single system over SSH connection and the entire operation can be handled and executed by one single command ‘ansible’. But, in some cases, where you required to execute multiple commands for a deployment, here we can build playbooks.
Playbooks are a bunch of commands which can perform multiple tasks, and each playbook are in YAML file format.
What’s the Use of Ansible?

Ansible can be used in IT infrastructure to manage and deploy software applications to remote nodes. For example, let’s say you need to deploy a single software or multiple software to 100’s of nodes by a single command, here ansible comes into picture, with the help of Ansible you can deploy as many as applications to many nodes with one single command, but you must have a little programming knowledge for understanding the ansible scripts.
We’ve compiled a series on Ansible, title ‘Preparation for the Deployment of your IT Infrastructure with Ansible IT Automation Tool‘, through parts 1-4 and covers the following topics.
What are the Advantages of Ansible?

– Agent-less
– very overload
– Good Performance.
Is there a web interface / REST API / etc?

Yes, Ansible, Inc makes a great product that makes Ansible even more powerful and easy to use. See Ansible Tower.
How do I submit a change to the documentation?

Documentation for Ansible is kept in the main project git repository, and complete instructions for contributing can be found in the docs.
When should I use {{ }}? Also, how to interpolate variables or dynamic variable names
A steadfast rule is ‘always use {{ }} except when when:‘. Conditionals are always run through Jinja2 as to resolve the expression, so when: failed_when: and changed_when: are always templated and you should avoid adding {{}}.
In most other cases you should always use the brackets, even if previously you could use variables without specifying (like with_ clauses), as this made it hard to distinguish between an undefined variable and a string.
Another rule is ‘moustaches don’t stack’. We often see this:
{{ somevar_{{other_var}} }}
The above DOES NOT WORK, if you need to use a dynamic variable use the hostvars or vars dictionary as appropriate:
{{ hostvars[inventory_hostname][‘somevar_’ + other_var] }}
How to install Ansible
Installation of Ansible Ubuntu 14.04
The best way to get Ansible for Ubuntu is to add the project’s PPA (personal package archive) to your system.
To do this effectively, we need to install the software-properties-common package, which will give us the ability to work with PPAs easily. (This package was called python-software-properties on older versions of Ubuntu.)
sudo apt-get update
sudo apt-get install software-properties-common
Once the package is installed, we can add the Ansible PPA by typing the following command:
sudo apt-add-repository ppa:ansible/ansible
Press ENTER to accept the PPA addition.
Next, we need to refresh our system’s package index so that it is aware of the packages available in the PPA. Afterwards, we can install the software:
sudo apt-get update
sudo apt-get install ansible
We now have all of the software required to administer our servers through Ansible.
How do I generate crypted passwords for the user module?

The mkpasswd utility that is available on most Linux systems is a great option:
mkpasswd –method=sha-512
If this utility is not installed on your system (e.g. you are using OS X) then you can still easily generate these passwords using Python. First, ensure that the Passlib password hashing library is installed.
pip install passlib
Once the library is ready, SHA512 password values can then be generated as follows:
python -c “from passlib.hash import sha512_crypt; import getpass; print sha512_crypt.encrypt(getpass.getpass())”
Use the integrated Hashing filters to generate a hashed version of a password. You shouldn’t put plaintext passwords in your playbook or host_vars; instead, use Vault to encrypt sensitive data.
Desired to gain proficiency on Ansible?

Explore the blog post on Ansible training to become a pro in Ansible.
How do I get ansible to reuse connections, enable Kerberized SSH, or have Ansible pay attention to my local SSH config file?
Switch your default connection type in the configuration file to ‘ssh’, or use ‘-c ssh’ to use Native OpenSSH for connections instead of the Python paramiko library. In Ansible 1.2.1 and later, ‘ssh’ will be used by default if OpenSSH is new enough to support ControlPersist as an option.
Paramiko is great for starting out, but the OpenSSH type offers many advanced options. You will want to run Ansible from a machine new enough to support ControlPersist, if you are using this connection type. You can still manage older clients. If you are using RHEL 6, CentOS 6, SLES 10 or SLES 11, the version of OpenSSH, is still a bit old, so consider managing from a Fedora or openSUSE client even though you are managing older nodes, or just use paramiko.
We keep paramiko as the default as if you are first installing Ansible on an EL box, it offers a better experience for new users.
What is the best way to make content reusable/redistributable?

If you have not done so already, read all about “Roles” in the playbooks documentation. This helps you make playbook content self-contained and works well with things like git submodules for sharing content with others.
If some of these plugin types look strange to you, see the API documentation for more details about ways Ansible can be extended.
How do I see all the inventory vars defined for my host?

You can see the resulting vars you define in inventory running the following command:
ansible -m debug -a “var=hostvars[‘hostname’]” localhost
How do I copy files recursively onto a target host?

The “copy” module has a recursive parameter, though if you want to do something more efficient for many files, look at the “synchronize” module instead, which wraps rsync. See the module index for info on both modules.
What is Ansible Role?

Ansible can interact with configured clients from the command line with the ansible command, and how you can automate configuration with playbooks run through the ansible-playbook command.
The first step in creating a role is creating its directory structure. To create the base directory structure, we’re going to use a tool bundled with Ansible called ansible-galaxy:
$ ansible-galaxy init azavea.packer
azavea.packer was created successfully
That command will create an azavea.packer directory with the following structure:
├── defaults
│ └── main.yml
├── files
├── handlers
│ └── main.yml
├── meta
│ └── main.yml
├── tasks
│ └── main.yml
├── templates
└── vars
└── main.yml
How do I access a variable name programmatically?

An example may come up where we need to get the ipv4 address of an arbitrary interface, where the interface to be used may be supplied via a role parameter or other input. Variable names can be built by adding strings together, like so:
{{ hostvars[inventory_hostname][‘ansible_’ + which_interface][‘ipv4’][‘address’] }}
The trick about going through hostvars is necessary because it’s a dictionary of the entire namespace of variables. ‘inventory_hostname’ is a magic variable that indicates the current host you are looping over in the host loop.
How do I access shell environment variables?

If you just need to access existing variables, use the ‘env’ lookup plugin. For example, to access the value of the HOME environment variable on management machine:

# …
local_home: “{{ lookup(‘env’,’HOME’) }}”
If you need to set environment variables, see the Advanced Playbooks section about environments.
Ansible 1.4 will also make remote environment variables available via facts in the ‘ansible_env’ variable:
{{ ansible_env.SOME_VARIABLE }}

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Manual Testing interview questions

1.Diff b/w regression & system testing
2. wht is a test plan.
3. contents of test plan & explain them u ever prepare the test plan
5. why do u looking for a change
6.diff phases in STlC & explain dem
7.write the testcases on the foolowing registration form which contains the fields like
Person name,address,pan no., his/her company name
8.what the monkey testing
9.what is frame work & types of frameworks
10.wht is hybrid frame work.
11.diff b/w keyword driven & data driven framework
12.write the vb script code on person name field that it shld not accept more than 65

Other interview questions

1. what is foreign key
2. difference btw function,procedure and sub procedure
3. write a test case for a room
4. write a test case for a bank statement
5. tellme about ur role
6. ur project architecture
7. what u will do if ur developer rejects the build
8. how u vl do retesting
9. when u vl do regression testing
10. why v do retesting
11. what u vl do if a bug is not reproduicible
12. what u vl do if ur getting the same bug arain and again
13. what is interesting about testing
14. as a test engineer what u liked about testing
15. which is the most critical bug u hav found in ur application
16. what are the ddocuments u vl get for writing the test cases
17. why u want to shift from ur current job
18. what is ur goal as a test engineer
19. at which stage of SDLC does testing starts
20. what is the objective of atest engineer
21. how many bugs u hav found till now
22. eplain me about ur project frame workd
23. what skills does a teste need to hav
24. which part of the application u find more difficult while testing
25. what u vl do if a bug reproduce again and again
26. which is the most challenging bug u hav found till now

27. why u hav taken testing as a carrer
28. when u vl say that u hav done a 100% testing
29. when u vl say that the application u hav tested is bug free
30. how u vl prove that the application u have tested does not have any bug
31. when does a application goes intop production
32. what is entry and exit criteria
33. what is review and hav u ever particiapated
34. what u vl do if ur team lead says that the bug u hav found is not valid but
according to it is valid
35. what u vl do if there is a misunderstandings btwn u and ur team lead
36. what is defect management
37. how u vl manage defect
38. give me the example of high severity and low priority
39. low severity high priority
40. low severity low priority
41. high severity and high priority

IBM Interview Questions?

1.Tell me about yourself professionally?.
2.What tool you u use for raising the defects?.What are al the fields u need to enter?.How
do u write the defect observation?.
3.Difference b/w smoke and Sanity testing.
4.Write 3 positive and -ve scenarios on the ATM M/c(Working of ATM M/c).
5.Test Case Format, what are all the field are there in test case format?.
6.Then some questions on sql , difference b/w where and having clause
7.Do u know joins?, different types of Joins and write a Left outer Join
8. IN Joins, is where required, instead of ON?.
9. Then some questions on UNIX, live what commands u know?.
10. How do u delete single char in a file(using vi)?
11.How do u replace a single char in a file?.
12.What are hard and soft links?.
13. what does .. do( cd ..)?

QTP Interview Questions

1. How to capture data from images in QTP and produce them in Excel sheet ?
2. What is Terminal Emulator add-in installation and configuration procedure ?
3. Tell me how do u define action and transaction in QTP ?
4. Is QTP case sensitive ?
5. Problem with XML checkpoint ?
6. When was QTP 8.2 and Loadrunner 8.0 officially released to the market ?
7. Can we record on netscape browser does it require any special settings ?
8. How do I add new object to the object repository to any particular frame ?

9. Do we have rapid test scrpit wizard in QTP ? How to learn all the windows and objects
in QTP
10. How to open Exceel sheet using QTP script ?
11. Is it necessary to learn VB script to work with QTP or we can manage with keword
driven ?
12. What is descriptive programming in QTP ?
13. How to invoke the QTP from dos prompt and run a test without any interaction with
human ?
14. What is the meaning of Context sensitive ?
15. How to retrive the property values from “” after recording the script with
“Standard checkpoints” ?
16. Where should we use accessbility checkpoints. Can u explain me with the example ?
17. How do we add object repository dynamically ? (During runtime)
18. How to record right click of a context menu and click on the selection ?
19. How to connect oracle database to QTP ?
20. How will you load few objects in Active Screen ?
21. Can I compare two DataBases using QTP ?
22. If the the two object have same class then how QTP will find the object ?
23. Can I change the runtime properties of an object ? How can I check if a parameter
exists in database ?
24. What is the script for database check point, bitmapchek point, regular expression ?
25. What is QTP environmental variable ?

“SEMANTIC SPACE” Testing Interview Questions

1.My Application performance is very poor how to troubleshoot.
2.After Patching and after reboot my machine is not coming into live how to
3.How to confirm That Physical server hardware is working fine, like
4.My application crashing how to troubleshoot
5.My system Start up takes a very long time how to troubleshoot.
6.In a group There are 100 members, and I only want to assign a group policy to 20
particular members of that group how to do it
7.What is configuration Management ?
Configuration Management is the process used to control, cooridinate and track
the entire SDLC
Configuration management is the process used to control, cooridinate and track

code, requirements, design, documentation problems, change requests, tools etc and
the changes made to them and who made the changes.
Configuration Management mainly focuses on two factors – ‘Change Control’ and
‘Version Control’.
8. change management : is for changing the version if any change is done due to a
change request from the customers.
3. What are Severity and priority levels ?
4. What is Data integrity and Data validity ?
5. What are the browsers available and explain their versions ?
6. Is it possible that Quality variates project to project ?
7. What are GUI Map files and explain their Contents ?
8. What is Data base check point and why we go for that ?
9. What is the difference between the Client server application and a Web application ?
10. Does Winrunner Supports Web applications ?
11. What is process Management ?
12. What is an Error, Defect, Bug ?
13. What is Quality ?
14. Which version of Winrunner you are using ?
15. What is Build Verification and why we go for it ?
16. What is Defect density ?
17. What is Integration testing ?
18. What is Static testing and types of Static testing ?
19. What is Validation testing ?
20. what is Data driven testing and why we go for data driven testing ?
21. what is the definition of Testing ?
22. What is Sanitation Testing ?

1.Explain Bug Life Cycle ?
2. What is Integration Testing and Regression Testing ?
3. What is Verification and Validation ?
4. How does Winrunner recognizes the project which is in custom build ?
5. What is expert view and tree view ?
6. How does QTP identify the project ?
7. What is the difference between Winrunner and QTP ?
8. What is Test Director and which version of test director your are using in your project
9. What is a test plans ?
10. what are the contents present in a test plan ?
11. What is the risk of testing a project ?


1. What is TOM in QTP ?
2. Tell me the QTP advantage and disadvantges ?
3. How to test background color and dynamic images during runtime can u put checkpoints for
moving images ?


1. What are the file extensions for pre-action,shared object repository files and what is the
extension for library files ?
2. What are the most frequent errors you faced while executing your scripts ? 
3. Among all the check points what is the most important check point ?

who will prepare test cases?
what is bottom-up integration testing
What is Quality System?
What is Independent Test Group (ITG)?
how many testing cases are design for day?
What is Smoke Testing?
tell me some typical bugs you encountered in your last assignment give some
What is mean by Test Strategy? is there any types?
What is GUI Testing

Can u give an Eg for High severity and low priority, High priority and low severity for
any web based and mobile application
What did we include in a test plan?
what is test harness?
What is the difference between quality assurance and quality control
why one should go for software testing and not to development

when we assign deferred status to bug give example
Are monkey testing & gorilla testing same? If not, then what is the difference between
these two?
what is the CMMI concept
how much interaction with users should testers have and why

Latest Open Questions

How will u do the load, stress & performance testing manually?
write a test case template with minimum of 13 to max of 20 columns?
Which are different links normally present on GUI ?
How to write security and cookie test cases for web application?
What is Scalability Matrix?
What is Independent Testing?
What is meant my Firewall testing? how the testing is performed on it?
While testing a bug has been found and reported but it was not fixed and delivered to the client what will be the effect on it?
What are the documents need for to write test cases?


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Interview questions for Azure

1. What is Cloud Computing?

Cloud computing is a term referred to storing and accessing data over the internet. It doesn’t store any data on the hard disk of your personal computer. In cloud computing, you are allowed accessing data from a remote server.

2. What is Microsoft Azure?

Azure is a cloud computing platform which was launched by Microsoft in Feb 2010. It is a highly flexible cloud platform that offers development, data storage, service hosting, and service management.

3. Explain the Importance of the role and how many types of roles are available in Windows Azure?

Roles are a very important concept in Windows Azure, and learning them is the base for further programming.

Three types of roles in Windows Azure are:

  • Web Role: It is used to deploy website by using langue which is supported by the IIS platform customized to run the web apps.
  • Worker Role: It helps you to execute the process that runs in the background by
  • VM Role: It helps you to schedule the windows services and task.

4. Why should you use Azure CDN?

Azure CDN should be used to reduce load time and bandwidth as well as speed the responsiveness.

5. Name some important applications of Microsoft Azure

Most important application of Microsoft Azure are:

Infrastructure Services, Mobile Apps, Web Applications, Cloud Services, Storage, Media Services, etc.

6. What is Azure as PaaS?

PaaS is a computing platform that includes an operating system, programming language execution environment, database, or web services. Developers and application providers use this type of Azure services.

7. Explain the crucial benefits of Traffic Manager

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.

8. What are Break-fix issues in Microsoft Azure?

In, Microsoft Azure, all the technical problem is called break-fix issues. This term uses when “work involved in support a technology when it fails in the normal course of its function.

9. Explain Diagnostics in Windows Azure

Windows Azure Diagnostic offers the facility to store diagnostic data. In Azure, some diagnostics data is stored in the table, while some are stored in a blob. The diagnostic monitor runs in Windows Azure as well as in the computer’s emulator for collecting data for a role instance.

10. State the difference between repetitive and minimal monitoring.

Verbose monitoring collects metrics based on performance. It allows a close analysis of data fed during the process of application.

On the other hand, minimal monitoring is a default configuration method. It makes the user of performance counters gathered from the operating system of the host.

11. What is the main difference between the repository and the powerhouse server?

The main difference between them is that repository servers are instead of the integrity, consistency, and uniformity while powerhouse server governs the integration of different aspects of the database repository.

12. Explain command task in Microsoft Azure

Command task is an operational window which set off the flow of either single or multiple common whiles when the system is running.

13. What are unconnected lookups?

Unconnected lookup the input ins take by the LKP operation. In this type of lookup method, User-defined values are disregarded in the unconnected lookups.

14.Explain Cmdlet command of Microsoft Azure

A cmdlet is a command which is utilized as a part of the Microsoft PowerShell environment. The cmdlet is called by the Windows PowerShell to automate the scripts which are in the command line.

15. What is the use of the Migration Assistant tool in Azure Websites?

Migration Assistant tool helps you to examine your IIS installation. It helps you to recognize which site can be migrated to the cloud. It is also featuring components which are either not migrated or unsupported on the Azure platform.

16. What is the use of Azure Active Directory?

Azure Active Directory is an identify and access management system. It is very much similar to the active directories. It allows you to grant your employee in accessing specific products and services within the network.

17. What is HDInsight in Microsoft Azure?

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.

18. Explain role instance in Microsoft Azure

A role instance is a virtual instance on which the application code and role configuration run. A role can have multiple instances, which are defined in the service configuration file.

19. Explain the term ‘service fabric’ in Azure

Service fabric is a middleware platform which gives more scalable outcome. It mostly renders with a more managed and reliable enterprise.

20. Explain Availability Set

It is a logical grouping of Virtual Machines. It allows the Azure cloud to build understand how the application for a user is built to provide availability and redundancy.

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Top 20 Python Interview Questions and Answers

1) What is Python? What are the benefits of using Python?

Python is a programming language with objects, modules, threads, exceptions and automatic memory management. The benefits of pythons are that it is simple and easy, portable, extensible, build-in data structure and it is an open source.

2) What is PEP 8?

PEP 8 is a coding convention, a set of recommendation, about how to write your Python code more readable.

3) What is pickling and unpickling?

Pickle module accepts any Python object and converts it into a string representation and dumps it into a file by using dump function, this process is called pickling. While the process of retrieving original Python objects from the stored string representation is called unpickling.

4) How Python is interpreted?

Python language is an interpreted language. Python program runs directly from the source code. It converts the source code that is written by the programmer into an intermediate language, which is again translated into machine language that has to be executed.

5) How memory is managed in Python?

  • Python memory is managed by Python private heap space. All Python objects and data structures are located in a private heap. The programmer does not have an access to this private heap and interpreter takes care of this Python private heap.
  • The allocation of Python heap space for Python objects is done by Python memory manager. The core API gives access to some tools for the programmer to code.
  • Python also have an inbuilt garbage collector, which recycle all the unused memory and frees the memory and makes it available to the heap space.

6) What are the tools that help to find bugs or perform static analysis?

PyChecker is a static analysis tool that detects the bugs in Python source code and warns about the style and complexity of the bug. Pylint is another tool that verifies whether the module meets the coding standard.

7) What are Python decorators?

A Python decorator is a specific change that we make in Python syntax to alter functions easily.

8) What is the difference between list and tuple?

The difference between list and tuple is that list is mutable while tuple is not. Tuple can be hashed for e.g as a key for dictionaries.

9) How are arguments passed by value or by reference?

Everything in Python is an object and all variables hold references to the objects. The references values are according to the functions; as a result you cannot change the value of the references. However, you can change the objects if it is mutable.

10) What is Dict and List comprehensions are?

They are syntax constructions to ease the creation of a Dictionary or List based on existing iterable.

11) What are the built-in type does python provides?

There are mutable and Immutable types of Pythons built in types Mutable built-in types

  • List
  • Sets
  • Dictionaries

Immutable built-in types

  • Strings
  • Tuples
  • Numbers

12) What is namespace in Python?

In Python, every name introduced has a place where it lives and can be hooked for. This is known as namespace. It is like a box where a variable name is mapped to the object placed. Whenever the variable is searched out, this box will be searched, to get corresponding object.

13) What is lambda in Python?

It is a single expression anonymous function often used as inline function.

14) Why lambda forms in python does not have statements?

A lambda form in python does not have statements as it is used to make new function object and then return them at runtime.

15) What is pass in Python?

Pass means, no-operation Python statement, or in other words it is a place holder in compound statement, where there should be a blank left and nothing has to be written there.

16) In Python what are iterators?

In Python, iterators are used to iterate a group of elements, containers like list.

17) What is unittest in Python?

A unit testing framework in Python is known as unittest. It supports sharing of setups, automation testing, shutdown code for tests, aggregation of tests into collections etc.

18) In Python what is slicing?

A mechanism to select a range of items from sequence types like list, tuple, strings etc. is known as slicing.

19) What are generators in Python?

The way of implementing iterators are known as generators. It is a normal function except that it yields expression in the function.

20) What is docstring in Python?

A Python documentation string is known as docstring, it is a way of documenting Python functions, modules and classes.

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Top 20 SDET Interview questions

1) State any difference between SDET and Manual Software Tester

The main difference between SDET and the Software tester is:

  • SDET (Software Development Engineer in Test) can participate in test automation
  • Manual Tester never involves in such type of activities.

2) What is the definition of ad hoc testing?

Adhoc testing is informal testing. It is performed without any planning and documentation. This kind of test is conducted randomly without any expected results.

3) State the difference between priority and severity

Priority means how important a bug is to be fixed, while severity means how- harmful or damaging the bug is to the system.

4) Describe roles and responsibilities of this job

  • Need to perform Test Automation and set up frameworks on platforms like Web and Mobile.
  • Create & manage bug reports and constantly remain in touch with the development team.
  • Communicate with clients
  • You should also be able to set up and manage test automation frameworks independently.

5) Discuss Typical working day of SDET

On a daily basis, you mostly occupied on the following tasks:

  1. Understand project requirements
  2. Creating and executing test cases
  3. Reporting and testing bugs

You also need to give your input to the design and development team.

6) How do you decide what product is ready to ship?

Upper management of the organization will take a call when a product is ready to ship when a testing team is certain that all bugs have been identified, documented, and resolved.. Although, SDET must make sure that management has all the information they need to make a correct decision.

7) What are the elements of a good bug report?

A good bug report contains a

  • Descriptive summary of the bug
  • The steps to reproduce the bug
  • The expected and real behavior of the bug

8) What are Alpha and Beta Testing?

Alpha Testing helps to identify all possible bugs before releasing the product to everyday users or the public. Beta Testing is performed by users of the software application in a real environment.

9) Name and explain the different categories that test cases are grouped by.

Some important types of test cases used in Software development are:

  • Functionality Test cases
  • User interface Test Cases
  • Performance Test Cases
  • Integration Test Cases
  • Usability Test Cases
  • Database Test Cases
  • Security Test Cases

10) How will You overcome the Challenges if the Proper Documentation for testing does not exist?

In the case when System Requirement Specification document is not available then,


As SDET you need to rely on the following references if available:

  • Screenshots
  • A previous version of the application.
  • Wireframes

11) State main difference Between Quality Assurance and Quality Control?

QA is more planned and systematic method of monitoring the quality of the process. This process is followed to produce quality software and application.Quality Control is related to the quality of the product. QC team never find the defects and suggests improvements.

12) What is the meaning of Code Inspection?

Code inspection allows the programmer to review their source code with a group who ask questions related to program logic, analyzing the code. It checks against some most common programming errors and verifies coding standards.

13) Discuss what Test Plan is?

The test plan is nothing but a document which describes the scope, approach, resources, and schedule of intended testing activities. In test plan, the tester needs to identify test items,

  • Features to be tested
  • Testing tasks
  • Risks involved in the process

14) What is the meaning of Test Script?

The test script is commonly used to refer to the instructions for a specific test that carried out by an automated test tool.

15) Describe configuration management?

Configuration management covers the processes which need to control, coordinate, and track:

  • Code
  • Documentation
  • Problems
  • Change requests
  • Designs, tools, patches
  • A person who makes the changes

16) What are walkthrough and inspection?

The walkthrough is just an informal process. This process is conducted by the author of the document. This type of inspection done mainly with the objective of providing information and collecting suggestions for improvement.

17) What is the objective of preparing the test plan?

The main objective of creating Test plan is:

  • Project scope
  • Roles and Responsibilities
  • Deadlines and deliverables.

18) How can you test text box without background functionality?

It is possible to check without passing any data like:

  1. Size of the Text Field
  2. Min/Max characters
  3. Special characters
  4. Alphanumeric values
  5. Text format

19) What kind of expertise expected out of SDET?

Testing software is done to assess and mitigate business risk, and SDETs need to be expert in this. The SDET should able to check the quality of the software and should take part in the software design process

20) Briefly explain Test Procedure

A test procedure is a document which provides detailed information for the execution of test cases.

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Top 15 R language Interview questions

1) Explain what is R?

R is data analysis software which is used by analysts, quants, statisticians, data scientists and others.

2) List out some of the function that R provides?

The function that R provides are

  • Mean
  • Median
  • Distribution
  • Covariance
  • Regression
  • Non-linear
  • Mixed Effects
  • GLM
  • GAM. etc.

3) Explain how you can start the R commander GUI?

Typing the command, (“Rcmdr”) into the R console starts the R commander GUI.

4) In R how you can import Data?

You use R commander to import Data in R, and there are three ways through which you can enter data into it

  • You can enter data directly via Data  New Data Set
  • Import data from a plain text (ASCII) or other files (SPSS, Minitab, etc.)
  • Read a data set either by typing the name of the data set or selecting the data set in the dialog box

5) Mention what does not ‘R’ language do?

  • Though R programming can easily connects to DBMS is not a database
  • R does not consist of any graphical user interface
  • Though it connects to Excel/Microsoft Office easily, R language does not provide any spreadsheet view of data

6) Explain how R commands are written?

In R, anywhere in the program you have to preface the line of code with a #sign, for example

  • # subtraction
  • # division
  • # note order of operations exists

7) How can you save your data in R?

To save data in R, there are many ways, but the easiest way of doing this is

Go to Data > Active Data Set > Export Active Data Set and a dialogue box will appear, when you click ok the dialogue box let you save your data in the usual way.

8) Mention how you can produce co-relations and covariances?

You can produce co-relations by the cor () function to produce co-relations and cov () function to produce covariances.

9) Explain what is t-tests in R?

In R, the t.test () function produces a variety of t-tests. T-test is the most common test in statistics and used to determine whether the means of two groups are equal to each other.

10) Explain what is With () and By () function in R is used for?

  • With() function is similar to DATA in SAS, it apply an expression to a dataset.
  • BY() function applies a function to each level of factors. It is similar to BY processing in SAS.

11) What are the data structures in R that is used to perform statistical analyses and create graphs?

R has data structures like

  • Vectors
  • Matrices
  • Arrays
  • Data frames

12) Explain general format of Matrices in R?

General format is

Mymatrix< - matrix (vector, nrow=r , ncol=c , byrow=FALSE,
dimnames = list ( char_vector_ rowname, char_vector_colnames))

13) In R how missing values are represented ?

In R missing values are represented by NA (Not Available), why impossible values are represented by the symbol NaN (not a number).

14) Explain what is transpose?

For re-shaping data before, analysis R provides various method and transpose are the simplest method of reshaping a dataset. To transpose a matrix or a data frame t () function is used.

15) Explain how data is aggregated in R?

By collapsing data in R by using one or more BY variables, it becomes easy. When using the aggregate() function the BY variable should be in the list.

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Top 20 Hadoop Interview questions

1) What is Hadoop Map Reduce?

For processing large data sets in parallel across a Hadoop cluster, Hadoop MapReduce framework is used.  Data analysis uses a two-step map and reduce process.

2) How Hadoop MapReduce works?

In MapReduce, during the map phase, it counts the words in each document, while in the reduce phase it aggregates the data as per the document spanning the entire collection. During the map phase, the input data is divided into splits for analysis by map tasks running in parallel across Hadoop framework.

3) Explain what is shuffling in MapReduce?

The process by which the system performs the sort and transfers the map outputs to the reducer as inputs is known as the shuffle

4) Explain what is distributed Cache in MapReduce Framework?

Distributed Cache is an important feature provided by the MapReduce framework. When you want to share some files across all nodes in Hadoop Cluster, Distributed Cache is used.  The files could be an executable jar files or simple properties file.

5) Explain what is NameNode in Hadoop?

NameNode in Hadoop is the node, where Hadoop stores all the file location information in HDFS (Hadoop Distributed File System).  In other words, NameNode is the centerpiece of an HDFS file system.  It keeps the record of all the files in the file system and tracks the file data across the cluster or multiple machines

6) Explain what is JobTracker in Hadoop? What are the actions followed by Hadoop?

In Hadoop for submitting and tracking MapReduce jobs,  JobTracker is used. Job tracker run on its own JVM process

Job Tracker performs following actions in Hadoop

  • Client application submit jobs to the job tracker
  • JobTracker communicates to the Name mode to determine data location
  • Near the data or with available slots JobTracker locates TaskTracker nodes
  • On chosen TaskTracker Nodes, it submits the work
  • When a task fails, Job tracker notifies and decides what to do then.
  • The TaskTracker nodes are monitored by JobTracker

7) Explain what is heartbeat in HDFS?

Heartbeat is referred to a signal used between a data node and Name node, and between task tracker and job tracker, if the Name node or job tracker does not respond to the signal, then it is considered there is some issues with data node or task tracker

8) Explain what combiners are and when you should use a combiner in a MapReduce Job?

To increase the efficiency of MapReduce Program, Combiners are used.  The amount of data can be reduced with the help of combiner’s that need to be transferred across to the reducers. If the operation performed is commutative and associative you can use your reducer code as a combiner.  The execution of combiner is not guaranteed in Hadoop

9) What happens when a data node fails?

When a data node fails

Jobtracker and namenode detect the failure

  • On the failed node all tasks are re-scheduled
  • Namenode replicates the user’s data to another node

10) Explain what is Speculative Execution?

In Hadoop during Speculative Execution, a certain number of duplicate tasks are launched.  On a different slave node, multiple copies of the same map or reduce task can be executed using Speculative Execution. In simple words, if a particular drive is taking a long time to complete a task, Hadoop will create a duplicate task on another disk.  A disk that finishes the task first is retained and disks that do not finish first are killed.

11) Explain what are the basic parameters of a Mapper?

The basic parameters of a Mapper are

  • LongWritable and Text
  • Text and IntWritable

12) Explain what is the function of MapReduce partitioner?

The function of MapReduce partitioner is to make sure that all the value of a single key goes to the same reducer, eventually which helps even distribution of the map output over the reducers

13) Explain what is a difference between an Input Split and HDFS Block?

The logical division of data is known as Split while a physical division of data is known as HDFS Block

14) Explain what happens in text format?

In text input format, each line in the text file is a record.  Value is the content of the line while Key is the byte offset of the line. For instance, Key: longWritable, Value: text

15) Mention what are the main configuration parameters that user need to specify to run MapReduce Job?

The user of the MapReduce framework needs to specify

  • Job’s input locations in the distributed file system
  • Job’s output location in the distributed file system
  • Input format
  • Output format
  • Class containing the map function
  • Class containing the reduce function
  • JAR file containing the mapper, reducer and driver classes

16) Explain what is WebDAV in Hadoop?

To support editing and updating files WebDAV is a set of extensions to HTTP.  On most operating system WebDAV shares can be mounted as filesystems, so it is possible to access HDFS as a standard filesystem by exposing HDFS over WebDAV.

17)  Explain what is Sqoop in Hadoop?

To transfer the data between Relational database management (RDBMS) and Hadoop HDFS a tool is used known as Sqoop. Using Sqoop data can be transferred from RDMS like MySQL or Oracle into HDFS as well as exporting data from HDFS file to RDBMS

18) Explain how JobTracker schedules a task?

The task tracker sends out heartbeat messages to Jobtracker usually every few minutes to make sure that JobTracker is active and functioning.  The message also informs JobTracker about the number of available slots, so the JobTracker can stay up to date with wherein the cluster work can be delegated

19) Explain what is Sequencefileinputformat?

Sequencefileinputformat is used for reading files in sequence. It is a specific compressed binary file format which is optimized for passing data between the output of one MapReduce job to the input of some other MapReduce job.

20) Explain what does the conf.setMapper Class do?

Conf.setMapperclass  sets the mapper class and all the stuff related to map job such as reading data and generating a key-value pair out of the mapper

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Top 20 Vmware Interview Questions and Answers

1) What is VMware and what are their benefits?

VMware provides different applications and software for virtualization.  VMware products are categorized into two levels, desktop applications, and Server applications.

It is useful for:

  • Running multiple operating systems and applications on a single computer
  • Consolidate hardware to get vastly higher productivity from fewer servers
  • Save more than 50% of total cost spend on IT
  • It simplifies IT management and speeds up the deployment of new applications

2) What are the different types of virtualization available?

Different types of virtualization available are

  • Application virtualization
  • Presentation virtualization
  • Network virtualization
  • Storage virtualization

3) Mention different types of server software do VMware provides?

VMware provides three different types of server software

  • VMware ESX Server
  • VMware ESXi Server
  • VMware Server

4) Explain what is hypervisor

A hypervisor is a program that enables multiple operating systems to share a single hardware host.  Each operating system has the host’s processor, memory and other resources all to itself.  The hypervisor controls the resources and host processor, allocating what is required for each operating system in turn and make sure that the guest operating system cannot disrupt each other.

5) Explain VMware DRS?

VMware DRS stands for Distributed Resource Scheduler; it dynamically balances resources across various host under a cluster or resource pool.  It enables users to determine the rules and policies which decide how virtual machines deploy resources, and these resources should be prioritized to multiple virtual machines.


6) Explain VMware Fault Tolerance?

VMware fault tolerance is an important component of VMware vSphere, and it offers continuous access to applications by preventing data loss and downtime of virtual machines in the event of ESX server failure.

7) What is FT logging traffic?

FT logging is one of the options in VMKernel port setting which is more or less the same as enabling vmotion option in the vmkernel port.

8) Name different components used in VMware infrastructure.

Different components used in VMware infrastructure includes

  • It consists of the lowest layer which acts as an ESX server host
  • It also uses the virtual center server which keeps tracks of all the VM associated images and manages it from one point
  • VMWare infrastructure client, it enables the client to communicate with user’s applications that are running on VMware
  • Web-browser is used to access the virtual machines
  • The license server is used to prepare a server which provides licensing to the applications
  • Database servers are availed to maintain a database

9) Explain vCloud Suite

vCloud Suite combines with multiple VMware components to give a complete set of cloud infrastructure capabilities in a single package, including virtualization, software-defined datacenter services, disaster recovery, application management, etc.

10) What are the storage and availability in vCloud Suite?

The storage and availability in vCloud Computing Suite includes

  • Storage DRS:It place and load balance virtual machines based on storage capacity and I/O latency
  • Storage vMotion:It employs proactive, non-disruptive storage migration to reduce virtual machine storage I/O bottlenecks and free up valuable storage capacity
  • Application HA:It gains high availability that is bound to specific applications
  • Data Protection: Based on EMC avamar, it deploys a back-up and recovery tool

11) What is Host Isolation in VMware HA (High Availability)?

In VMware HA, it has a mechanism to detect a host isolated from the rest of the hosts in the cluster.  In simple words, it uses a heartbeat to communicate another host in the cluster. When the ESX host loses its ability to connect with other hosts in a cluster through heart-beat, then ESX host will be considered as a Host Isolation.

12) What is the difference between VMware HA and Vmware FT?

VMware FT is enabled per VM basis while VMware is enabled per cluster

In the case of ESX host failure, virtual machines are the failed host and are re-started and powered-on the other active hosts in HA cluster. But FT-enabled virtual machines; there is no downtime. In the case of a host failure, the secondary VM will be activated, and it becomes primary and continue to run from the exact point where the primary VM is failed or left off.

13) Explain the new features available in vSphere 5?

In the latest version of vSphere 5.5, it includes

  • ESXi Hypervisor enhancement
  • Virtual Machine Enhancement
  • VMware vCenter Server Enhancement
  • vSphere storage Enhancement
  • vSphere Networking Enhancements

14) What are the new features included in ESXi Hypervisor enhancement?

In ESXi Hypervisor enhancement includes

  • Hot-pluggable PCIe SSD Devices:It supports SSDs (Solid State Disks) devices, and with a new enhancement, SSD device can be removed or added while a vSphere host is running.
  • Support for Reliable Memory Technology: vSphere ESXi hypervisor can take advantage of new hardware; vendor enabled Reliable Memory Technology, through which a region of memory is reported from the hardware to vSphere ESXi hypervisor. It is used to enhance the placement of VMKernel and other components like initial thread and hosted. It helps to protect against memory error
  • Enhancements to CPU C-states: A power process (C-state) is used to provide additional power savings

15) State out the difference between template and clone in VMware?

16) What is Fault Tolerant Logging?

The communication between two ESXI host is known as Fault logging when FT is configured between them.

17) Explain vSS

vSS stands for Virtual Standard is responsible for communication of VMs hosted on a single physical host. It automatically detects a VM which wants to communicate with other VM on the same physical server.

18) Explain some features of VMware tool

  • It offers a simple wizard for setting configuration
  • Web browser interface
  • Easy maintenance of virtual machines

19) Define the term ’VMKenel’.

VMWare Kernel is a proprietary kernel of VMware. It needs an operating system to boot and manage the kernel. A service console is being offered whenever VMWare kernel is booted.

20) What is the purpose of using  Virtual Machine Port Group?

Virtual Machine port group helps for Virtual machine communication.

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