DevOps top interview Questions

by | Oct 20, 2022 | DevOps | 0 comments

What is DevOps?

Development and operations are the abbreviations for the term “DevOps.” It is a software engineering method that integrates the development and operations teams to fully automate the project.

This technique facilitates the easy automation of project service management to support operational objectives and better awareness of the technological stack utilized in the production environment.

The key advantages of adhering to this structure are the speed with which difficulties are resolved at the production environment level, the stability of applications, and the creativity involved.

DevOps Tools

The DevOps paradigm relies on good tooling to enable teams to deploy and develop for their customers in a timely and dependable manner. These solutions assist teams in managing complicated systems at scale, as well as maintenance engineers in charge of the high velocity offered by DevOps.

Who is a DevOps engineer?

A DevOps engineer works with software developers and IT professionals to guarantee that code releases go well. They are often developers who get interested in the deployment and operations domain or system administrators who become interested in coding and wish to work in development.

A DevOps engineer understands the SDLC (Software Development Lifecycle) and automation technologies for constructing CI/CD pipelines.

What is the use of SSH?

The administration protocol known as SSH, or Secure Shell, enables users to connect to and control remote servers over the Internet using the command line.

SSH is a secure, encrypted version of Telnet, which was formerly unencrypted and insecure. This guaranteed that communications with the remote server were encrypted. SSH also offers techniques for remote user authentication, client-to-host input communication, and output delivery back to the client.

What is configuration management?

Configuration management (CM) is the process of handling changes so that the system does not lose its integrity over time. This includes rules, approaches, procedures, and tools for analyzing, managing, and tracking change proposals and maintaining relevant documentation.

 Importance of having configuration management in DevOps?

By helping the team automate labor-intensive and time-consuming operations, configuration management (CM) eventually increases the performance and agility of the company.

It also aids in uniformity and enhances the product development process through design streamlining, detailed documents, control, and change implementation throughout the project’s many phases and releases.

What is Continuous Integration (CI)?

Continuous Integration (CI) is a software development method in which developers integrate their code into a shared repository as soon as they finish working on a feature. Each integration is validated using an automated build process, which allows teams to spot flaws in their code early on rather than after release.

Why is Continuous Integration needed?

It has been discovered that implementing Continuous Integration for both development and testing has increased software quality and substantially decreased the time required to deploy software features.

Because each commit to the shared repository is automatically created and run against the unit and integration test cases, the development team can find and fix mistakes early on.

What are the three important DevOps KPIs?

  • Reduce the average time required to recover from a failure.
  • Increase the frequency with which deployments occur.
  • Reduced the percentage of deployments that fail.

Explain the different phases in DevOps methodology.

  • Planning:

This is the initial stage of the DevOps lifecycle and entails understanding the project to provide the best product possible. 

When completed correctly, this phase provides numerous inputs for the development and operations stages. This phase also assists the company in gaining an understanding of the project creation and management process.

This is accomplished using tools such as Google Apps, Asana, Microsoft Teams, and others.

  • Development:

The development phase comes after the planning phase. The project is constructed by creating system infrastructure, adding features by writing code, and then defining test cases and the automation process. Developers save their code in a code manager called a remote repository, which facilitates team collaboration by providing code viewing, modification, and versioning.

Tools such as git, IDEs such as Eclipse and IntelliJ, and technological stacks such as Node, Java, and others are employed.

  • CI (Continuous Integration):

This phase enables code validation, building, and testing to be automated. This ensures that the modifications are made correctly and without development environment issues and provides for early detection of errors.

Jenkins, CircleCI, and other tools are utilized here.

  • Deployment:

DevOps assists in the deployment automation process by utilizing tools and scripts with the ultimate goal of automating the process through feature activation. 

In this case, cloud services can be leveraged as a driving force to help transition the management of finite infrastructure to the management of cost-optimized infrastructure with the possibility of infinite resources.

Microsoft Azure, Amazon Web Services, Heroku, and other tools are used.

  • Operations:

Due to dynamic infrastructure changes, this phase frequently occurs throughout the product lifecycle. This allows the team to improve the product’s availability, scalability, and effectiveness.

In this phase, tools such as Loggly, BlueJeans, Appdynamics, and others are frequently employed.

  • Monitoring¬†is a continuous phase of the DevOps approach. This phase monitors and analyzes data to determine the state of software applications.

Commonly used tools include Nagios, Splunk, and others.

How is DevOps different than Agile Methodology?

DevOps attempts to bridge the gap between developers and the operations team to ensure a successful product launch.

Agile is a software development process that emphasizes incremental, iterative, and quick releases of software features while incorporating the client through feedback. This methodology bridges the gap between the clients’ and developers’ understanding of the requirements.

What can you say about the anti-patterns of DevOps?

A pattern is something that big groups of entities regularly follow.

  • If an organization adopts a design solely because it is being followed by others, without considering the organization’s needs, it becomes an anti-pattern.
  • A pattern is something that large groups of entities follow regularly.

Can you list down specific KPIs used for gauging the success of DevOps?

  • Usage, performance, and traffic of applications.
  • Percentage of Passes for Test Case Automation
  • Availability of the application
  • Requests for volume changes.
  • Tickets for customers.
  • Frequency and timing of successful deployment.
  • Error and failure rates.
  • Deployment failures.
  • The time between detection and detection (MTTD).
  • In the meantime, recovery (MTTR).

What exactly is CBD in DevOps?

CBD is an abbreviation for Component-Based Development. It is a novel method of product creation. Here, developers continue to hunt for existing well-defined, tested and verified code components to relieve the developer of the burden of coding from scratch.

What exactly is resilience testing?

Resilience testing is a software method that evaluates an application’s behaviour in uncontrolled and turbulent environments. It also ensures that data and functionality are not lost in a breakdown.

What is the DevOps pipeline?

A pipeline is a collection of automated tasks or processes specified and followed by the software engineering team. A DevOps pipeline is a pipeline that enables DevOps engineers and software developers to compile, build, and deploy software code to production settings efficiently and reliably.

The flow is as follows:

devops pipeline

How does Ansible work?

For this to operate, Ansible must be installed on the controlling system, from which the nodes are managed through SSH. The location of the nodes would be determined and configured in the controlling machine’s inventories.

Because Ansible is agentless, no installations are required on the remote node servers. As a result, no background processes are required for handling remote nodes.

Using Ansible Playbooks and an SSH connection, Ansible can manage several nodes from a single control system. Playbooks use the YAML format and can conduct several activities.

What can be done to prepare for developing a project utilizing the DevOps methodology?

Stage 1: Plan: Create a roadmap for execution by conducting a thorough review of the existing processes to identify opportunities for improvement and blind spots.

Stage 2: Proof of Concept: Create a proof of concept (POC) to understand the intricacies required. Once the proof of concept is approved, the project’s actual implementation work will begin.

Stage 3: Adapt to DevOps: Once the project is ready for deployment, the authentic DevOps culture should be followed. It can be implemented using phases such as version control, continuous integration, testing, deployment, delivery, and monitoring.

Do you know about DevOps postmortem meetings?

Post Mortem meetings are held to discuss what went wrong during the implementation of the DevOps technique. When this meeting is held, it is expected that the team will arrive at the steps. 

The group will determine the actions that must be taken to prevent further failures.

What is the meaning of Sudo in Linux?

The term “superuser do” is referred to by the acronym “sudo,” with the root user of Linux being the superuser. It is a tool for Linux and Unix-based systems that allows users with superuser rights to execute system commands at the root level.

Can you describe Jenkins’s architecture?

The master-slave architecture is used by Jenkins. Whenever a commitment is made to the code, the master downloads the most recent version from the GitHub repository. The build, test, and run procedures, as well as the creation of test case reports, are delegated to slaves by the master. This workload is distributed equally across the slaves.

Jenkins also employs numerous slaves because it’s possible that after code updates, it may be necessary to run several test case suites for various environments.

jenkins server

Can you describe the concept of “infrastructure as code” (IaC)?

As the name implies, IaC primarily relies on perceiving infrastructure like any other code. This is also known as “programmable infrastructure.” It provides a mechanism for defining and managing the IT infrastructure through configuration files.

Because of the restrictions associated with the old method of managing infrastructure, this concept rose to prominence. Traditionally, infrastructure was controlled manually, and dedicated personnel was required to physically set up the servers.

The application would not have been deployed until this stage was completed. Manual configuration and setup were prone to human errors and inconsistencies.

What exactly is the dogpile effect? How can it be avoided?

It is also known as the “cache stampede,” It can occur when massive parallel computing systems using caching algorithms are subjected to an extremely high load.

 It is the occurrence that occurs when the cache expires (or is invalidated) when numerous requests to the website are made at the same time. 

The most common method of preventing dogpiling is to use semaphore locks in the cache. When the store expires, the first process to obtain the key will generate a new value for the cache.

What exactly is the Blue/Green Deployment Pattern?

A blue-green pattern is continuous deployment, an application release pattern that focuses on progressively transitioning users from a previously functional version of the program or service to a nearly similar new release, both of which are now in use.

The blue environment represents the old version of the application, while the green environment represents the current version.

The production traffic would be gradually transferred from the blue to the green environment, and once entirely transferred, the blue background would be kept on hold only in case of a rollback requirement.

blue and green deployment

Conclusion

DevOps is a culture-shifting practice that has and continues to benefit many businesses and organizations significantly. It aids in bridging the gap between the developer’s (continuous need for change) and operation’s (constant opposition to change) goals and priorities by paving the way for Continuous Development and Continuous Integration.

Because of the growing demand for DevOps expertise, becoming a DevOps engineer provides numerous advantages.