70+ Devops Interview Questions and Answers

Use 'pkill' command with '-f' option to kill all java processes.

• Open terminal or command prompt

• Type 'pkill -f java' and press enter

• All java processes will be terminated

Setup microservice testing and deployment using Kubernetes, containers, Jenkins, and Cloud services.

• Create a Kubernetes cluster on a Cloud provider

• Build Docker containers for each microservice

• Create a Jenkins pipeline for testing and deployment

• Use Kubernetes to deploy and manage the containers

• Use Cloud services for load balancing, monitoring, and scaling

To run cmd commands using python on windows, use the subprocess module.

• Import the subprocess module

• Use the subprocess.run() method to execute the command

• Pass the command as a list of strings to the run() method

• Use the shell=True argument to run the command in a shell environment

• Capture the output of the command using the stdout attribute of the returned CompletedProcess object

Automated server monitoring reduced downtime and improved response time for critical issues in our infrastructure.

• Identified frequent server downtime as a major issue affecting productivity.

• Implemented a monitoring tool (e.g., Prometheus) to track server health metrics.

• Set up automated alerts to notify the team of any anomalies or performance degradation.

• Created scripts to automatically restart services that went down, minimizing manual intervention.

• Regularly reviewed logs an...read more

Yes, by using regular expressions to match phone number patterns.

• Use regular expressions to match phone number patterns

• Common phone number patterns include (XXX) XXX-XXXX and XXX-XXX-XXXX

• Consider international phone number formats as well

• Use a programming language with regex support, such as Python or JavaScript

Deep copy creates a new object with a new memory address while shallow copy creates a new object with the same memory address as the original object.

• Deep copy creates a completely new object with a new memory address.

• Shallow copy creates a new object with the same memory address as the original object.

• In deep copy, changes made to the copied object do not affect the original object.

• In shallow copy, changes made to the copied object affect the original object.

• Deep copy is used...read more

Stages in pipeline job in Jenkins

• Checkout code from version control system

• Build the code

• Run unit tests

• Deploy to staging environment

• Run integration tests

• Deploy to production environment

• Send notification email

Ansible playbook to copy files based on the operating system using conditional statements.

• Use the 'copy' module to transfer files.

• Utilize 'when' statements to check the OS type.

• Example: - name: Copy file for Ubuntu copy: src: /path/to/source dest: /path/to/destination when: ansible_os_family == 'Debian'

• Example: - name: Copy file for CentOS copy: src: /path/to/source dest: /path/to/destination when: ansible_os_family == 'RedHat'

• Gather facts using 'gather_facts: yes' to determi...read more

Use inotifywait command to monitor file changes in Linux.

• Install inotify-tools package

• Use inotifywait command with options like -m for continuous monitoring and -e for specific events

• Example: inotifywait -m /var/log/messages -e modify

• Output will show the file path, event type and timestamp

Chef is a configuration management tool used for automating infrastructure deployment and management.

• Chef helps in automating the process of configuring and managing servers and applications.

• It allows for consistent and repeatable infrastructure deployments.

• Chef can be used to manage both on-premises and cloud-based infrastructure.

• It provides a centralized platform for managing configurations and enforcing policies.

• Chef can be integrated with other DevOps tools like Jenkins a...read more

To identify the process causing server slowness, use monitoring tools and analyze system logs.

• Use monitoring tools like Nagios, Zabbix, or Prometheus to track system performance metrics.

• Analyze system logs to identify any errors or warnings related to specific processes.

• Check CPU and memory usage of running processes using tools like top or htop.

• Use profiling tools like strace or perf to identify resource-intensive processes.

• Consider network traffic and disk I/O as potential ...read more

Optimise SQL query by identifying bottlenecks and improving indexing and query structure.

• Identify slow performing queries using profiling tools

• Improve indexing by adding or removing indexes

• Rewrite query structure to reduce complexity and improve performance

• Use query optimisation techniques like subqueries and joins

• Consider caching frequently accessed data

SSL certification can be configured with Tomcat by generating a keystore file and configuring the server.xml file.

• Generate a keystore file using keytool command

• Configure the server.xml file to include the keystore file and password

• Update the connector element in server.xml to include the SSL protocol and port number

• Restart Tomcat to apply the changes

Ruby program to check directory existence and write permissions.

• Use File.exist? method to check if directory exists.

• Use File.writable? method to check if directory has write permissions.

• Combine both methods to get the desired result.

A container is a lightweight, standalone executable package that contains everything needed to run an application.

• Containers provide a consistent and reproducible environment for applications to run in.

• They are isolated from the host system and other containers, providing security and portability.

• Containers can be easily deployed and scaled, making them ideal for modern application development and deployment.

• Examples of container technologies include Docker, Kubernetes, and O...read more

Dockerfile to setup Nginx and expose it with port 8080

• Use the official Nginx image as the base image

• Copy the custom Nginx configuration file to the container

• Expose port 8080 in the Dockerfile

• Start Nginx in the foreground using the CMD instruction

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications.

• Kubernetes is used to manage and automate the deployment of containerized applications.

• It provides features like automatic scaling, load balancing, and self-healing.

• Kubernetes allows for easy management of containers across multiple hosts and clusters.

• It provides declarative configuration and efficient resource utilization.

• Kubernet...read more

To install IIS using PowerShell, use the Install-WindowsFeature cmdlet.

• Open PowerShell as an administrator

• Run the command: Install-WindowsFeature -name Web-Server -IncludeManagementTools

• Press 'Y' to confirm installation

• Wait for the installation to complete

Read Replicas require a transactional storage engine and are only supported for the InnoDB storage engine.

• InnoDB is the default storage engine for MySQL, providing ACID compliance.

• Read Replicas allow for horizontal scaling of read operations, improving performance.

• InnoDB supports transactions, foreign keys, and row-level locking, essential for data integrity.

• Other storage engines like MyISAM do not support transactions, making them unsuitable for Read Replicas.

Namespace in Docker is a way to isolate resources and avoid naming conflicts.

• Namespaces provide a layer of isolation for containers

• Each namespace has its own set of resources

• Namespaces can be used for network, process, and mount isolation

• Example: docker run --name mycontainer --net=container:othercontainer myimage

Integrating Maven with Jenkins

• Install Maven plugin in Jenkins

• Configure Maven installation in Jenkins global tool configuration

• Create a new Jenkins job and select Maven project

• Specify the path to the pom.xml file in the project configuration

• Configure build triggers and other settings as required

Linux boot process involves several stages including BIOS, bootloader, kernel initialization, and user space initialization.

• BIOS performs a power-on self-test and loads the bootloader from the boot device.

• Bootloader loads the kernel into memory and initializes it.

• Kernel initializes hardware, mounts the root file system, and starts the init process.

• Init process starts user space processes and services.

• Linux boot process can be customized by modifying bootloader configuration a...read more

A process in Linux is a running instance of a program or command.

• A process is identified by a unique process ID (PID)

• Processes can be started, stopped, and managed using commands like ps, kill, and top

• Processes can run in the foreground or background

• Processes can communicate with each other through inter-process communication (IPC)

• Examples of processes include web servers, database servers, and user applications

To troubleshoot high CPU usage, analyze processes, check logs, and optimize configurations.

• Use 'top' or 'htop' command to identify processes consuming high CPU.

• Check system logs for errors or warnings using 'tail -f /var/log/syslog'.

• Analyze application performance metrics with tools like Prometheus or Grafana.

• Review recent changes or deployments that may have impacted performance.

• Consider scaling resources or optimizing code if specific applications are consistently high.

Azure and AWS are cloud computing platforms with similar services, but differ in pricing, scalability, and integration.

• Azure is more tightly integrated with Microsoft products, while AWS has a wider range of third-party integrations.

• AWS has a larger market share and more mature services, while Azure is catching up quickly.

• Azure offers more flexible pricing options, while AWS has a more complex pricing structure.

• Azure has better support for hybrid cloud environments, while AWS...read more

TFS is a comprehensive tool for project management and version control, while SCM focuses on source code management.

• TFS (Team Foundation Server) integrates version control, project management, and build automation.

• SCM (Source Control Management) primarily focuses on tracking changes in source code.

• TFS supports Agile methodologies, allowing teams to plan, track, and discuss work.

• Examples of SCM tools include Git, Subversion, and Mercurial, which are primarily for code versioni...read more

Prometheus achieves high availability and scalability through federation, sharding, and horizontal scaling.

• Prometheus uses federation to collect data from multiple Prometheus servers and aggregate it into a single view.

• Sharding allows Prometheus to distribute the workload across multiple instances, improving performance and reliability.

• Horizontal scaling involves adding more Prometheus servers to handle increased data volume and traffic.

• Prometheus also supports clustering for...read more