DevOps Engineer interview must have asked 33

DevOps Interview Questions

01 Can you tell us the fundamental difference between Agile and DevOps (agile) between you?

A: Although DevOps and agile methods (which is one of the most popular SDLC [Software Development Life Cycle] method) has some similarities, but both in the development of software is a fundamentally different approach. The following are various basic differences between them:

• 敏捷方法 Agile method is suitable for the agile development method is suitable for DevOps agility at the same time in the development and operation.
• 实践和流程 Agile Agile Scrum and Agile Kanban involves other practical, and DevOps involving CD (continuous delivery), CI (continuous integration) and CT (continuous testing) and other processes.
• 优先级 Agility priority timeliness, and DevOps priority to timeliness and quality.
• 发布周期 DevOps provide a smaller release cycle and providing immediate feedback, and provide only a small agile release cycles without immediate feedback.
• 反馈源 Agility depends on customer feedback, and DevOps related to (monitoring tool) feedback itself.
• 工作范围 For quick, agile scope of work only, and for DevOps, which is agile and demand for automation.

02 Why do we need DevOps?

A: Today, many organizations or companies are trying to release a small number of properties passed to the customer, rather than release large feature set. This has several benefits, including better software quality and fast customer feedback, all of these benefits lead to higher customer satisfaction, which is the most important goal of any product development project. To do this, companies need to:

• Increase the frequency of deployment
• Shorten time to repair
• Reduce the failure rate of new versions
• In case a new version crashes, there is a faster mean time to recovery

DevOps help meet all these requirements, enabling seamless software delivery. Like Amazon, Etsy and Google have adopted such a mature organization DevOps methods, in order to achieve a previously unknown level of performance. By adopting DevOps methods, organizations can deploy tens of thousands of completed in one day. In addition, doing so can also provide first-class 可靠性, 安全性and 稳定性.

What are the key business and technical advantages of the use of 03 DevOps there?

A: DevOps brought a lot of business and technical advantages for the table. Here are some of the most important parameters:

• Commercial interests:

  • Enhanced operating environment stability
  • Faster delivery function
  • More time to add value
• Technical advantages:
  • Continuous delivery software
  • Faster problem resolution
  • Less complex issues

04 Can you list some of the most commonly used DevOps tool?

A: The following is a list of some of the most widely used DevOps tools:

• Ansible / Puppet / chef / saltstack - configuration management and application deployment tools
• Docker - container tools
• Git / Gitlab - version control system (VCS) tools
• Jenkins - Continuous Integration (CI) tool
• Nexus - Products Database Management Tool
• Jira - agile team collaboration tools
• wiki - Document Management Tools
• Promtheus - Continuous monitoring tool
• Selenium / jmeter - continuous testing (CT) Tools

What is the use of 05 Selenium?

A: selenium for DevOps consecutive tests. This tool specializes in the form of functional and regression testing.

06 What is your understanding of the DevOps of Puppet?

A: This is a configuration management tool to automate administrative tasks. Puppet using the master-slave structure, wherein the two entities to communicate over an encrypted channel. The system administrator needs to perform many repetitive tasks, especially in installing and configuring the server. Write scripts to automate such tasks is an option, but when is large infrastructure operations performed becomes tedious repetition. For this reason, configuration management is a good solution.

Puppet help configure, deploy and manage servers. This not only makes such redundant tasks easier, but also save a large part of total work time. Mature configuration management tools:

• Continuously checks the host configuration required is in place. If you change the configuration will automatically restore
• Each host is defined as different configurations
• The machine dynamic scaling (scaling down)
• All configured to provide control of the computer, so that focus can be changed automatically propagated to all these computers

07 What is your understanding of the DevOps anti-pattern?

A: DevOps mode if other organizations usually do not work in a particular environment, and the organization continues to use it, it will lead to the use of anti-pattern. In other words, anti-pattern is the myth of DevOps. Some well-known anti-patterns are:

• An organization needs to have a separate set of DevOps
• DevOps agility equal
• DevOps is a process
• DevOps is a development-driven release management
• As the only organization unique, and therefore can not be DevOps
• We can not do it because we have DevOps cattle
• DevOps means that developers manage production
• DevOps will solve all the problems
• It can not contain all of the organization's ongoing transition in DevOps
• DevOps undefined transition at the start of KPI
• To reduce the isolation between other organizations through a new DevOps team

08 DevOps there is something called the CI. What it is, what is the purpose?

A: CI representatives in DevOps continuous integration. CI is a development practices, developers can integrate multiple code to a shared repository in a single day.

• Continuous integration and test development to improve software quality and reduce the total time required for delivery.
• If the inspection team members met to compile the code fails, the developers will terminate build. If the developer does not compile errors introduced their own workspace, then the other members of the development can not be synchronized with the shared source code repository.
• This undermines the collaboration and sharing of the development process. Therefore, once the configuration items to build interrupted immediately identify and correct the problem is very important.
• Typically, the continuous integration (CI) process includes a set of unit, integration and regression tests that run each time compile successfully. If any of these tests fail, CI building will be considered to be unstable (which is common in Agile sprint, since development in progress), and is not destroyed.

09 We often hear DevOps left. What is it?

A: The painting on paper of traditional software development life cycle right and left. The left side of FIG include design and development, including the production phase and the right side, stress testing, and user acceptance. Left in the DevOps movement only means that you need to perform as many tasks on the right side, that usually occurs at the end of the application development process, and included in its early stages DevOps approach. There are several ways DevOps operation can be completed, the most noteworthy are:

• Create a quick sprint at the end of each file can be used to produce (product file)
• In each version contains static code analysis program
• DevOps correct execution level is directly dependent on the degree of the left as possible.

10 DevOps CAMS behalf of what?

A: The acronym CAMS often used to describe the core tenets of DevOps methodology. It represents:

• Culture Culture
• Automation Automation
• Metric Measurement
• Share Sharing

11 What used to assess the success of several KPI is DevOps?

A: kpi is shorthand for key performance indicators. In order to measure the success of DevOps process, you can use several kpi. Among the most popular are:

• Application Performance
• Use and traffic applications
• Automatic test pass rate
• Availability
• Body mass changes
• Customer work orders
• Defect escape rate
• Frequency deployment
• Deployment time
• Error rate
• Number of failed deployment
• Load Time
• The average detection time (the MTTD)
• The average recovery time (MTTR)

12 What do you think the main benefits of implementing DevOps automation is?

A: The following is the main benefit of implementing DevOps automation:

• Eliminating the possibility of human error (core earnings) from the CD equation
• As the task becomes more predictable and repeatable, if there are problems, it is easy to identify and correct. Thus, it produces a more reliable and robust system
• Removing bottlenecks from CI pipe. This will lead to reduce the number of deployed and deploying increasing frequency of failure. They are important DevOps KPI

13 What do you know about the container?

A: The container is a lightweight form of virtualization, it helps to provide isolation between processes. Container heavier than chroot, but lighter than the hypervisor.

14 you have any knowledge of the version control system (VCS)? Define its purpose.

A: The version control system or VCS is a system capable of recording over time the changes made to a file or group of files. Git and Mercurial are the two most popular version control system. VCS is important use:

• What is the final cause of the problem is to modify inspection
• Compare with the changes over time
• Identify who at what time raise new questions
• Restore one or more files to an earlier state
• The entire project will revert to a previous state

15 Git is popular DevOps tools. Tell us how you have to push and to restore public submission.

A: There are two ways to do this:

1. Submitted by creating a new push to undo it has been disclosed and submit all changes. Execute the following command:

   git revert

2. By repair or delete the wrong file a new submission, and then push it to the remote repository. After making the necessary changes to the file, use the following command to submit it to the remote repository:

   git commit -m "commit message"

16 What is the post mortem meetings?

Reference answer: At this meeting, we discussed what's wrong, what steps should be taken, such a failure does not occur again. Post hoc analysis of the meeting is not to find the crux of the problem, but to prevent the recurrence of similar work, and problem management in ITIL is similar to management. And should be re-plan the new design infrastructure in order to reduce downtime. If we can not avoid mistakes, we should learn from mistakes, to submit the overall quality of IT management.

Comparison between the 17 asset management and configuration management.

A: The monitoring and maintenance of the entity or group of things of value is called asset management. Configuration management refers to the control, configuration item identification, planning and verification services to support the process of change management.

18 Can you represent and explain the key elements of each successive test?

A: The key elements of the various ongoing testing include:

• Advanced Analysis - used to predict future events and predict unknown
• Tactics - the means to improve the testing process
• Refers to the ability to describe demand as well as demand from the origin to the deployment of the entire process - requirements traceability
• Risk assessment - to identify possible hazards and potential damage of the risk factors of method or process
• Service virtualization - Allows virtual services instead of production services. Simulation software components for a simple test
• Test optimization - improve the overall testing process

19 Please indicate DevOps from core operations, and infrastructure development.

A: DevOps core operations, and infrastructure development are:

• Application development - development that meets all customer requirements and deliver superior levels of product quality
• Code Coverage - code measurements performed at run automatically test blocks, the total number of lines or arcs
• Code development - ready product required to develop code base
• Configuration - a great way to use the product
• Deployment - software installation to be used by the end user
• Choreography - arrange some automated tasks
• Packaging - launches when ready to deploy involved
• Supply - infrastructure changes to ensure timely arrival with the code need it
• Unit Test - Test method for a single unit or assembly

20 What is your understanding of the DevOps?

Your answer must be simple and straightforward. First, tell us about the importance of DevOps in the IT industry. This approach aims to discuss how to enable developers and operations teams work together to minimize the failure rate of software to accelerate product delivery. DevOps practices including how to become a value-added, development and operation and maintenance engineers throughout the product or service lifecycle (from design stage to the point of deployment) work together.

21 Why DevOps become prominent in recent years?

Before talking about the growing popularity of DevOps, please discuss the current industry conditions. First, an example of how Facebook and Netflix and other large companies to invest in DevOps to automate and accelerate application deployment and how it helped them grow their business. In Facebook's case, you will figure out how to continue to deploy and Facebook code ownership model, and these models help expand the scale, while ensuring quality of experience. We realized hundreds of lines of code without affecting the quality, stability and security.

The next use case should be Netflix. This streaming and on-demand video company with fully automated processes and systems follow a similar approach. The two organizations mentioned user base: Facebook 20 million users, while Netflix online content will be streamed to more than 100 million users worldwide.

These are good examples of how DevOps helps organizations ensure a higher success rate of release, reducing preparation time between bug fixes, by automating and simplifying the continuous delivery, and reduce labor costs overall.

22 What is the most popular DevOps tools? Do you have experience with these tools?

More popular DevOps tools include:

• selenium
• ansible
• Go / gitlab
• jenkins
• docker

23 Do you want to master all these Devops tools?

Thoroughly describe any tool that you have confidence in, its function and why to use it. For example, if you have the expertise in terms of Git, you can tell the interviewer Git is a distributed version control system (VCS) tool, which allows users to track file changes and revert to the specific changes if needed. Discuss how Git's distributed architecture to bring more benefits to developers, so that developers can make changes locally, and can have the whole project history in its local Git repository, it can later be shared with other team members.

24 What is version control? Why use VCS?

Custom version control, and discuss how the system records any changes made to one or more files and save them in a centralized repository. VCS tool will help you recall the previous version and do the following:

• A closer look at the changes over a period of time, then check what works and what does not.

• Specific files or revert back to the old version of the particular project.
• Check for problems that occur due to specific changes or errors
• The VCS provides the flexibility to handle specific files for developers, and all future content can be logically combined.

Is there a difference between 25 and Agile DevOps? If yes, please explain.

As a DevOps engineer, looking forward to this interview questions. Significant overlap between the described first and DevOps agility. Although DevOps implementations always keep pace with agile methods, but there are significant differences between the two. Agile principles relating to seamless production or development software. On the other hand, DevOps process development and deployment of software to ensure faster turnaround time, the smallest error and reliability.

26 Why Configuration Management processes and tools are important?

Discussions are developing more software for each software or test software build, release, modification, and version. Demand continues to illustrate the storage and maintenance of data, tracking the development of building and simplify troubleshooting. Do not forget to mention key CM tools can be used to achieve these objectives. Discussions such as how to help automate software deployment on multiple servers and configuration process Puppet, Ansible and tools like Chef's.

How 27 Chef as a CM tool?

chef is considered one of CM tool industry preferred. For example, Facebook to its back-end IT infrastructure and migrate to the Chef platform. Chef explain how to help you avoid delays through automated processes. These scripts are written in Ruby. It can integrate and configure the new system with cloud-based platform. It provides a number of libraries for infrastructure development, these libraries can be deployed later in the software. With its centralized management system, a Chef server center enough to be used to deploy various strategies.

28 How do you explain the concept of "Infrastructure as Code" (IaC) of?

Talk about IaC is a good idea, sometimes referred to as programmable infrastructure, the infrastructure, and the perception of the same way any other code. How to describe the traditional infrastructure management methods take a back seat, as well as manual configuration, how outdated tools and custom scripts reliability. Next, focus on the benefits of IaC, and how to use IaC faster, safer, easier to make changes to the IT infrastructure. IaC including other benefits, such as the conventional unit testing and integration testing applied to infrastructure configuration, and maintenance of new infrastructure documents.

If you have completed the Amazon Web Services (AWS) certification, and being interviewed niche roles such as AWS certified DevOps engineers and the like, then you will need some of the following AWS DevOps interview questions:

29 AWS what role in DevOps is?

When asked this question in the interview, please explain, AWS Amazon offers cloud-based service, to ensure scalability through unlimited computing power and storage. AWS enables IT organizations to develop and deliver complex products, and deploy applications in the cloud. Some of its key services include Amazon CloudFront, Amazon SimpleDB, Amazon Relational Database Service and Amazon Elastic Computer Cloud. Discuss various cloud platforms, and stressed that any items you are used to big data cloud infrastructure processed.

30 What continuous integration success factors?

• Maintenance code base
• Build Automation
• Let build self-test
• Each code will be submitted to the baseline day
• Each commit (to baseline) should be built
• Maintain a rapid build
• In the pre-release testing environment
• Easy access to the latest deliverables
• Everyone can see the results of the latest version
• Automated Deployment

How do you practice in our company DevOps?

Reference answer: As a DevOps engineer, I would DevOps management objectives of project management, quick delivery, continuous integration management, and "Agile Project Management" from the new agile project management triangle, set goals with the team, simplified the ITIL workflow, maintain agile DevOps scope of management, research and the introduction of new technology or framework, through DevOps pipeline, from a demand into the workflow from the overall global optimization tool chain.

What is the role of configuration management tools in devops is?

Reference answer: configuration management tools to support complete configuration item refers to the identification, version control, change control, audit and state statistical tools such tasks. Automated configuration management tools can help implement DevOps technical basis for sustained support of the pipeline. Using CM tools can be helped manage and store information about the system, software, test and build the relevant version and configuration information, and provide traceability between software and testing software. Successful DevOps starting configuration management.

What are the responsibilities DevOps engineer is?

Reference answer: DevOps engineers work closely with agile development teams, standing in the perspective of business value, driving IT to deliver business requirements from operations, ensured by high-quality (JKK) automated testing, continuous integration and achieve the desired sustained delivery technology and other IT functions environment of. DevOps engineers must keep contact and Development (SRE mode, Toyota, sustained delivery models, collaborative mode), so that all parts of the required environment can seamlessly work to achieve high-quality incremental iteration. You can be extended talk about the tools.