How Does Kubernetes Orchestrate Containers
Kubernetes Containers are scheduled to run based on their scheduling policy and the available resources.
Every Pod that needs to run is added to a queue and the scheduler takes it off the queue and schedules it. If it fails, the error handler adds it back to the queue for later scheduling.
What Is Ci What Is Its Purpose
CI or Continuous Integration is the process of compiling the entire code base, every time a member of the software development team checks the code, into the shared source code repository.
If a team member checks into the code file with a bug, then the build gets broken. In this sort of scenario, other developers cant synchronize the shared source code repository without introducing compilation errors into their own local workspaces. Thus, collaborative and shared software development cannot go forward.
When a CI build breaks, it is crucial that the problem is corrected immediately. A CI process often includes a suite of unit, and integration and regression tests that run every time the compilation succeeds. If any of these tests fail, the build will be considered unstable, not broken.
What Is Jenkins Pipeline And Ci/cd Pipeline
Jenkins Pipeline can be defined as a suite of plugins supporting both implementation and integration of Jenkins continuous delivery pipeline.
Continuous integration or continuous delivery pipeline consists of build, deploy, test, and release. The pipeline feature is very time-saving. In other words, a pipeline is a group of build jobs that are chained and integrated in a sequence.
Recommended Reading: Online Bootcamp For Coding Interviews
Question : Why Is Devops Necessary
Candidates can start by describing the current trend in the IT industry. Rather than deploying big sets of features, companies are experimenting with the provision of small features through multiple release trains.
This means companies have to accelerate the delivery of software products with a low failure rate and provide quick fixes to ensure fast recovery if the new release crashes. The advantages of this approach include better software quality and prompt customer feedback, which will ensure better customer satisfaction.
To achieve this, there is a need to create synergy between the development and operations teams. Development and operations engineers will collaborate all through the product or service lifecycle, from the design phase to deployment.
DevOps handles this and helps to ensure hitch-free software delivery. Many companies who adopted DevOps have managed to attain performance levels that may have been impractical a few years back. They can now deploy tens or hundreds of codes daily with higher efficiency, security, and stability.
Q7 Mention Some Of The Core Benefits Of Devops
- Faster development of software and quick deliveries.
- DevOps methodology is flexible and adaptable to changes easily.
- Compared to the previous software development models, confusion about the project is decreased due to increased product quality.
- The gap between the development team and operation team is bridged. i.e, the communication between the teams has been increased.
- Efficiency is increased by the addition of automation of continuous integration and continuous deployment.
- Customer satisfaction is enhanced.
You May Like: Sap Analytics Cloud Interview Questions
What Is Dogpile Effect How Can It Be Prevented
It is also referred to as cache stampede which can occur when huge parallel computing systems employing caching strategies are subjected to very high load. It is referred to as that event that occurs when the cache expires and multiple requests are hit to the website at the same time. The most common way of preventing dogpiling is by implementing semaphore locks in the cache. When the cache expires in this system, the first process to acquire the lock would generate the new value to the cache.
What Is Continuous Integration
Continuous integration is one of the key features of DevOps, so an engineer will need to understand this concept and demonstrate their understanding with a clear and detailed explanation.
Example:”Continuous integration is an automated process by which developers incorporate code from different sources into one integrated piece of software. It’s foundational to DevOps because it allows teams to work on projects one feature at a time. This speeds up the development process.”
Read Also: Where To Buy Interview Clothes
Continuous Integration Interview Questions And Answers
7. What do you mean by Continuous Integration?
8. What are the requirements for Continuous Integration?
9. How will you move Jenkins from one server to another?
10. How can you set up a Jenkins job?
11. What, according to you, are some of the useful plugins in Jenkins?
12. How can you secure Jenkins?
Name A Few Popular Devops Tools Which One Do You Prefer
As an experienced DevOps professional, the candidate should know about all the leading tools available and have hands-on knowledge of at least one or two tools. When the interviewer asks this question, it is advisable to answer with a comprehensive list of tools in the market and then elaborate on the benefits of the tool you have used. The top DevOps tools that should be on your radar include:
See More: Top 10 Must-Have DevOps Tools in 2021
Don’t Miss: What Questions To Ask During A Phone Interview
Latest Devops Engineer Interview Questions And Answers
DevOps is probably the most widely used term in technology today, despite the fact that it encompasses much more than buzz. It is a collaboration between the turn of events and tasks groups, in which they work together to deliver an object more quickly and efficiently. Regardless, the job market is extremely competitive, and the questions posed during a DevOps engineer interview will cover a wide variety of research topics. If you’ve started planning for advancement and role employment in the IT industry, you’re aware that it’s a challenging area that requires genuine preparation to join.
Can You Tell Me Why I Should Use Nagios For Http Monitoring
Nagios can provide us the complete monitoring service for our HTTP servers and protocols. Here are a few benefits of implementing effective HTTP monitoring with Nagios:
- Server, services, and application availability can be increased.
- Network outages and protocol failures can be detected quickly.
- User experience can be monitored.
- Web server performance can be monitored.
- Web transactions can be monitored.
- URLs can be monitored.
Recommended Reading: How To Analyse An Interview
Q9 What Is Selenium Ide
My suggestion is to start this answer by defining Selenium IDE. It is an integrated development environment for Selenium scripts. It is implemented as a Firefox extension, and allows you to record, edit, and debug tests. Selenium IDE includes the entire Selenium Core, allowing you to easily and quickly record and play back tests in the actual environment that they will run in.Now include some advantages in your answer. With autocomplete support and the ability to move commands around quickly, Selenium IDE is the ideal environment for creating Selenium tests no matter what style of tests you prefer.
What Are The Steps To Be Undertaken To Configure Git Repository So That It Runs The Code Sanity Checking Tooks Before Any Commits How Do You Prevent It From Happening Again If The Sanity Testing Fails
Sanity testing, also known as smoke testing, is a process used to determine if its reasonable to proceed to test.Git repository provides a hook called pre-commit which gets triggered right before a commit happens. A simple script by making use of this hook can be written to achieve the smoke test.
The script can be used to run other tools like linters and perform sanity checks on the changes that would be committed into the repository.
The following snippet is an example of one such script:
#!/bin/shfiles=$if thenexit 0fiunfmtd=$if thenexit 0fiecho Some .py files are not properly fmtdexit 1
The above script checks if any .py files which are to be committed are properly formatted by making use of the python formatting tool pyfmt. If the files are not properly formatted, then the script prevents the changes to be committed to the repository by exiting with status 1.
You May Like: What Are The Most Popular Interview Questions
What Are The Differences Between Devops And Agile
DevOps arose largely as an alternative to Agile workflows like Scrum. The key differences include:
- DevOps brings together all teams involved in software development and maintenance, whereas Agile typically siloes specific tasks to different teams
- DevOps emphasizes consistency, stability, and automation, whereas Agile focuses on adaptability and iterative development
- DevOps encompasses the full flow of software from ideation to delivery and maintenance, whereas Agile generally ends with the completion of code
Q4 How To Automate Testing In Devops Lifecycle
I have mentioned a generic flow below which you can refer to:In DevOps, developers are required to commit all the changes made in the source code to a shared repository. Continuous Integration tools like Jenkins will pull the code from this shared repository every time a change is made in the code and deploy it for Continuous Testing that is done by tools like Selenium as shown in the below diagram.In this way, any change in the code is continuously tested unlike the traditional approach.
Don’t Miss: How To Prepare For Cna Interview
Q18 What Is Ansible Module
Modules are considered to be the units of work in Ansible. Each module is mostly standalone and can be written in a standard scripting language such as Python, Perl, Ruby, bash, etc.. One of the guiding properties of modules is idempotency, which means that even if an operation is repeated multiple times e.g. upon recovery from an outage, it will always place the system into the same state.
Q1 What Is Continuous Testing
I will advise you to follow the below mentioned explanation:Continuous Testing is the process of executing automated tests as part of the software delivery pipeline to obtain immediate feedback on the business risks associated with in the latest build. In this way, each build is tested continuously, allowing Development teams to get fast feedback so that they can prevent those problems from progressing to the next stage of Software delivery life-cycle. This dramatically speeds up a developers workflow as theres no need to manually rebuild the project and re-run all tests after making changes.
Recommended Reading: What To Expect In A Second Interview
Q2 Why Do You Need A Continuous Integration Of Dev & Testing
For this answer, you should focus on the need of Continuous Integration. My suggestion would be to mention the below explanation in your answer:Continuous Integration of Dev and Testing improves the quality of software, and reduces the time taken to deliver it, by replacing the traditional practice of testing after completing all development. It allows Dev team to easily detect and locate problems early because developers need to integrate code into a shared repository several times a day . Each check-in is then automatically tested.
Why Are Ssl Certificates Used In Chef
- SSL certificates are used between the Chef server and the client to ensure that each node has access to the right data.
- Every node has a private and public key pair. The public key is stored at the Chef server.
- When an SSL certificate is sent to the server, it will contain the private key of the node.
- The server compares this against the public key in order to identify the node and give the node access to the required data.
Also Check: Pre Recorded Video Interview Introduction
Q9 How Does Nagios Help With Distributed Monitoring
The interviewer will be expecting an answer related to the distributed architecture of Nagios. So, I suggest that you answer it in the below mentioned format: With Nagios you can monitor your whole enterprise by using a distributed monitoring scheme in which local slave instances of Nagios perform monitoring tasks and report the results back to a single master. You manage all configuration, notification, and reporting from the master, while the slaves do all the work. This design takes advantage of Nagioss ability to utilize passive checks i.e. external applications or processes that send results back to Nagios. In a distributed configuration, these external applications are other instances of Nagios.
What Is The Difference Between Git Merge And Git Rebase
Suppose you are working on a new feature in a dedicated branch, and another team member updates the master branch with new commits. You can use these two functions:
To incorporate the new commits into your feature branch, use Git merge.
- Creates an extra merge commit every time you need to incorporate changes
- But, it pollutes your feature branch history
As an alternative to merging, you can rebase the feature branch on to master.
- Incorporates all the new commits in the master branch
- It creates new commits for every commit in the original branch and rewrites project history
Also Check: What Are The Basic Interview Questions
Explain Pair Programming With Reference To Devops
Pair programming is an engineering practice of Extreme Programming Rules. In this method, two programmers work on the same system, on the same design/algorithm/code.
One programmer act as a driver. Other acts as an observer who continuously monitor the progress of a project to identify problems. The roles can be reversed at any point of time without any prior intimation.
What Are The Main Types Of Devops Tools
Organizations use several different types of DevOps tools, including:
- Version control tools, such as Git
- Continuous integration tools, such as Jenkins
- Configuration management tools, such as Puppet
- Containerization tools, such as Docker
- Cloud tools, such as AWS
- Monitoring tools, such as Nagios
Also Check: How To Pass A Customer Service Interview
Q8 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 commandgit 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 usegit reset soft HEAD~N & & git commit edit -m$
Q9 What Is Git Bisect How Can You Use It To Determine The Source Of A 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 isgit bisect < subcommand> < options> Now since you have mentioned the command above, explain what this command will do, This command uses a binary search algorithm to find which commit in your projects 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.
Also Check: How To Pass An Interview Successfully
Explain How You Can Minimize The Memcached Server Outages
- When one instance fails, several of them go down, and this will put a larger load on the database server when lost data is reloaded as a client make a request. To avoid this, if your code has been written to minimize cache stampedes then it will leave a minimal impact
- Another way is to bring up an instance of Memcached on a new machine using the lost machines IP address
- The code is another option to minimize server outages as it gives you the liberty to change the Memcached server list with minimal work
- Setting timeout value is another option that some Memcached clients implement for Memcached server outage. When your Memcached server goes down, the client will keep trying to send a request till the time-out limit is reached
What Is The Demand For Devops Engineer
Internet and Software Development have transcended the world to an ever-transformative place. Every day there is something new brewing up in not just the tech sector but different industries. With the latest technology of AI, automation, Cloud, robotics, every industry wants to make a digital presence through websites, applications on different platforms. From communicating to analyzing their statistics, everything needs software.
Therefore, it could not be denied that to build reliable, innovative, efficient software that could help in scaling business and industries, a DevOps engineer is bridging the gap between two siloed teams i.e., development and operations. This clearly indicates a higher demand for a DevOps engineer who will be responsible for bringing an innovative perspective to the traditional companies.
You May Like: How To Crack Amazon Interview
What Are The Key Differences Between Containerization And Virtualization
Containerization and virtualization are the two most popular methods for hosting applications in a computer system.
Virtualization allows developers to run multiple operating systems on the hardware of a single physical server. Containerization enables developers to deploy multiple applications under the same operating system on a single virtual machine or server.
Can You Tell Me What Continuous Testing And Automation Testing Are
Automation testing, as the name suggests, is a process of automating the manual process of testing. It involves the use of separate testing tools that let developers create test scripts that can be executed repeatedly without any manual intervention.
Continuous testing is nothing but the process of executing automated tests as part of the software delivery pipeline in DevOps. In this process, each build is tested continuously, allowing the development team to get fast business feedback so that it can prevent the problems from progressing to the next stage of the software delivery lifecycle. This will dramatically speed up a developers workflow. He/she no longer needs to manually rebuild the project and re-run all tests after making changes.
Also, Check out our blog on Manual Testing vs Automation Testing.