top 40 DevOps QA blog

Top 40 Devops Interview Questions and Answers for 2021

This blog on DevOps Interview Questions and Answers has been developed by SMEs and industry experts with more than 15 years of DevOps expertise. You’ll find some of the most often asked questions in this sector here to help you prepare for realistic job interviews. During the DevOps interview, recruiters frequently ask the following DevOps questions.
  1. Tell me about DevOps in your own words?
Development and operations are referred to as DevOps. It’s a software engineering practice that focuses on bringing the development and operations teams together to automate the project at every level. This method makes it simple to automate project service management to support operational goals and gain a better grasp of the technological stack in use in the production environment. This approach is based on agile methodology and emphasizes team communication, resource management, and collaboration. 2. How can one become a DevOps Engineer? A DevOps engineer collaborates with software developers as well as IT personnel to guarantee that code releases go well. Developers who develop an interest in the deployment and operations domain, or system administrators who develop a passion for coding and want to move into development. In a nutshell, a DevOps engineer is someone who understands the SDLC (Software Development Lifecycle) and automation tools for CI/CD pipeline development. 3. What are the most important components or ideas of DevOps? The most important feature or principle of DevOps is
  • Infrastructure in the form of code
  • Deployment indefinite
  • Automated systems
  • Observation
  • Safety is paramount.
4. Explain SSH in your own words. Secure Shell, or SSH, is an administrative protocol that allows users to access and administer remote servers via the command line via the Internet. SSH is a secure encrypted version of Telnet, which was formerly unencrypted and insecure. This assured that all communications with the remote server are encrypted. SSH additionally includes features for remote user authentication, input communication between the client and the host, and output delivery to the client. 5. What are the main DevOps activities in terms of application development and infrastructure? The key DevOps operations are Development of an Application
  • Creating code
  • Coverage of the code
  • Testing at the unit level
  • Packaging and Distribution
Infrastructural development
  • Preparation
  • Organizing
  • Integration
  • Release
6. Which scripting language does a DevOps engineer use commonly? A DevOps engineer will benefit from a simplified scripting language. Python appears to be popular. 7. What are some of the most widely used DevOps tools? The following are some of the most popular DevOps tools:
  • Jenkins
  • Docker
  • Ansible
  • Git
  • Nagios
  • Monit
  • ELK (Elasticsearch, Logstash, Kibana)
8. Why is Configuration Management important in DevOps? Configuration management (CM) assists the team in automating time-consuming and repetitive operations, improving the organization’s performance and agility. It also aids in the consistency and improvement of the product development process by utilizing design streamlining, detailed documentation, control, and change implementation throughout the project’s many phases/releases. 9. What is CAMS in DevOps? Culture, Automation, Measurement, and Sharing are the acronyms for CAMS. It captures the foundation of DevOps. 10. Why do you need Continuous Integration? The software quality has increased and the time taken to provide the features of the product has been considerably lowered by implementing Continuous Integration for both development and testing. Because every commit to the shared repository is produced automatically and performed against the unit and integration test cases, the development team can find and solve mistakes early on. 11. Tell us when will you use SSH? I’ve logged into a remote system and worked on the command line using SSH. In addition, I’ve used it to tunnel into the system to provide safely encrypted conversations between two untrusted hosts over an unsecured network. 12. Name a few cloud platforms that are utilized to implement DevOps. The following are some of the most popular cloud computing platforms for DevOps implementation:
  • Google Cloud
  • Amazon Web Services
  • Microsoft Azure
13. What is Memcached? Memcached is a distributed memory object caching technology that is free and open source. Memcached’s main goal is to improve the response time for data that would otherwise have to be recovered or constructed from another source or database. It’s used to avoid having to repeatedly query a SQL database or another source for data for a concurrent request. 14. Mention some of Memcached’s key features? CAS Tokens: A CAS token is a unique identifier that is connected to an object that has been fetched from a cache. You can save your changed object using that token. Binary protocol: With the latest client, you can utilize binary protocol instead of ASCII. getDelayed: It shortens the time it takes for your script to wait for results from a server. Callbacks: They make the code easier to understand. 15. Explain in detail the Dogpile effect? When a cache expires, websites are attacked by several requests sent by the client at the same time, which is known as the dogpile effect. A semaphore lock can be used to prevent this effect. When the value in this system expires, the first process takes over the lock and begins creating fresh value. 16. Is it possible to classify DevOps as an Agile methodology? DevOps might be thought of as a complement to Agile, although it is not identical to it. 17. Is there a difference between git fetch and git pull? The command ‘git pull’ changes the target branch in the local repository by pulling any new commits from a branch from the central repository. Git fetch, on the other hand, is a variant of git pull. It pulls all new commits from the specified branch and places them in a new branch in the local repository, unlike ‘git pull’. ‘git fetch’ must be followed by a ‘git merge’ to incorporate these changes in your target branch. Only after merging with the fetched branch (where we did git fetch) will the target branch be updated. We may also use an equation to interpret the whole thing: git pull = git fetch + git merge 18. What is the procedure for enabling startup sound in Ubuntu? To Activate the startup sound
  • Select Control Gear, then Startup Applications from the drop-down menu.
  • To add an entry to the Startup Application Preferences box, click Add.
  • Then, in comment fields such as Name, Command, and Comment, write in the information.
/usr/bin/system-gtk-play—id= “desktop-login”—description= “play login sound”
  • Once you’ve finished, log out and then log back in.
You can also use the shortcut key Ctrl+Alt+T to open it. 19. Explain how to make launchers on an Ubuntu desktop. In Ubuntu, you can utilize launchers to create launchers on your desktop. By pressing ALT+F2 and then typing “gnome-desktop-item-edit –create-new/desktop,” the classic GUI window will open, and a launcher will be created on your desktop. 20. Will it ever try to get key data from that one failed Memcache server if you have numerous Memcache servers and one of them fails and has your data? The data on the failed server is not lost, but there is an option for auto-failure that you can set up for several nodes. Fail-over can occur when a socket or Memcached server error occurs, but not when a client error occurs, such as updating an existing key. 21. Is data stored in Memcached still accessible after a server is shut down? Because Memcached data is not persistent, if a server is shut down or restarted, all of the data in Memcached is lost. 22. How will you not use Memcached?
  • Memcached is frequently misunderstood as a data store rather than a cache.
  • Never rely solely on Memcached to get the data you need to run your application. Data should always be available from a different source.
  • Memcached is only a key-value store, thus you can’t query the data or cycle through the contents to retrieve information.
  • Memcached has no security features, such as encryption or authentication.
23. Tell us the difference between Memcache and Memcached? Memcache: It’s an extension that lets you deal with procedural and object-oriented (OOP) interfaces. It’s made to lighten the load on databases in dynamic web applications. Memcached: This is a Memcached extension that makes use of the libmemcached package to provide an API for communicating with Memcached servers. It’s used to boost the performance of dynamic web applications by reducing database load. It is the most recent API. 24. Give two examples of docker networking tools. Kubernetes and Docker Swarm are two options for docker networking. 25. Tell us about CBD? Component-Based Creation, or CBD, is a novel approach to product development. Instead of starting from scratch, developers use this strategy to compose and integrate existing well-defined, tested, and confirmed components into a product. 26. Do you know what DevOps post mortem meetings are? Post-mortem meetings are convened to discuss what went wrong during the implementation of the DevOps technique. It is expected that the team will arrive at steps that need to be made to avoid future failures when this meeting is held. 27. How do I use WebDriver to start a browser? Firefox: WebDriver driver = new FirefoxDriver(); Google chrome: WebDriver driver = new ChromeDriver(); Internet Explorer: WebDriver driver = new InternetExplorerDriver(); 28. Why should you use Selenium Grid? It can be used to run the same or different test scripts on several systems and browsers at the same time, allowing for distributed testing. It enables testing in a variety of contexts while significantly reducing execution time. 29. Tell the difference between driver.close() and driver.quit() Closes the focused browser window with the driver.close command. The driver.quit command, on the other hand, invokes the driver.dispose method, which closes all browser windows and terminates the WebDriver session. 30. How to backup and copy files in Jenkins? All we have to do is back up our JENKINS HOME directory regularly to build a backup. This holds all of our job’s build configurations, as well as the configurations of our slave nodes and our build history. Simply duplicate this directory to build a backup of our Jenkins configuration. A job directory can also be copied to clone or replicate a job, or renamed. 31. How is Ansible working? Ansible is a free and open-source automation tool that has two types of servers. Controlling machines and Nodes. Ansible will be installed on the controlling machine, and nodes will be managed through SSH using that machine. The positions of nodes are determined by inventories in the controlling machine. Ansible does not require any obligatory installations on remote nodes because it is an agentless technology. As a result, no background processes are required to be run while it manages any nodes. With the help of Ansible Playbooks, Ansible can manage a large number of nodes from a single machine over an SSH connection. Playbooks are multi-tasking scripts that are stored in the YAML file format. 32. What is the difference between an Ansible Playbook and an ad-hoc command? Ad-hoc commands are used to accomplish a task fast and are often used only once. Ansible Playbook, on the other hand, is used to automate repetitive tasks. There are times when we need to employ ad-hoc commands to complete a non-repetitive task. 33. Write down the syntax for building the docker image? We use the following command to create a docker image: docker build –f <file_name> -t image_name:version 34. Tell me the concept of sudo in Linux? Sudo is a tool for Unix/Linux-based systems that allows certain users to run particular system commands at the root level of the system. It’s an acronym for “super user do,” where “super user” refers to the “root user.” 35. Tell me about Pair Programming? Pair programming is an Extreme Programming Rules engineering technique. Two programmers are working on the same system, on the same design or method in this scenario. One programmer acts as a Driver, while the other acts as an Observer, constantly monitoring the development of a project to discover issues. The roles can be switched at any time without warning. 36. Describe the jobs that are engaged in DevOps. DevOps Architect: The person who is in charge of the entire DevOps process. DevOps Engineer: The Engineer must have prior experience with Agile, SCM or Version Control, CI/CD, and the setup of automation tools for the same, Infrastructure automation, and Database management. A DevOps engineer can be any developer with coding or scripting abilities and the desire to work in deployment or system administration. 37. Tell us about Puppet Manifests? In Puppet Master, every Puppet Node or Puppet Agent has its configuration details expressed in the native Puppet language. These details are called Puppet Manifests and are written in a language that Puppet understands. The .pp extension is used in the filenames of these manifests, which are made up of Puppet codes. For example, in Puppet Master, we may construct a manifest that creates a file and install Apache on all Puppet Agents or slaves connected to the Puppet Master. 38. What function does AWS play in DevOps? AWS is a cloud service that plays the following DevOps role: Flexible services: AWS gives us implementation resources that are ready to utilize. Scaling: Depending on the requirements, we can deploy thousands of computers on AWS. Automation: AWS assists us in automating work through a variety of services. Security: We can safeguard our deployments and builds by using its security options (IAM). 39. Identify some DevOps best practices that should be followed for DevOps success. Here are some of the most important DevOps best practices:
  • The time it takes to get any work into the production environment is referred to as the speed of delivery.
  • Keep track of how many flaws are discovered in each category.
  • In the event of a failure in the production environment, it’s critical to determine the real or average time it takes to recover.
  • The amount of defects reported by the consumer has an impact on the application’s quality.
40. Name a few useful network monitoring tools. The following are some of the most popular network monitoring tools:
  • Wireshark
  • Splunk
  • Icinga 2
  • Nagios
  • OpenNMS
FINAL WORDS: DevOps is a culture-shifting strategy that has and continues to benefit a wide range of enterprises and organizations. It creates a seamless path for Continuous Development and Continuous Integration, bridging the gap between the developers’ (continuous need for change) and operations’ (continuous opposition to change) goals and priorities. Because of the growing demand for DevOps skills, becoming a DevOps engineer provides numerous advantages. NSCHOOL ACADEMY have coupled DevOps interview questions for freshers, and DevOps interview questions for experienced in the above section. Hope you have thoroughly enjoyed going through the above question and answers. We now wish best of luck with your DevOps interview.