Introduction Real-time notification systems have become a key feature of modern web applications, enabling users to receive instant updates without refreshing the page. Whether it’s a new message, task assignment, order status update, or system alert, real-time notifications help improve user engagement, streamline communication, and enhance the overall user experience.… Continue Reading Building a Real-Time Notification System with Node.js, Socket.IO, and React

Introduction When an application running on a Linux server needs to connect to an external service, the system must identify the correct destination and network path before sending the traffic. For example, when a process tries to connect to a domain such as example.com, the domain name is first resolved… Continue Reading How the Linux Kernel Handles Network Connections Using DNS and Routing

Introduction Metabase is a popular open-source business intelligence platform that allows users to connect various databases and create dashboards and reports. While databases are typically added through the Metabase web interface, administrators can automate the process using the Metabase REST API and command-line tools such as curl. This article explains… Continue Reading How to Add a Database to Metabase via CLI Using the REST API

Introduction While setting up Container1 inside an OpenVZ container, I encountered the following error: ls: cannot access /dev/net/tun: No such file or directory This occurs when the TUN/TAP device is not enabled for the container. Since many networking applications rely on /dev/net/tun to create virtual network interfaces, its absence can… Continue Reading Fixing the /dev/net/tun Error in an OpenVZ Container

Introduction In environments where application servers and database servers communicate over a private network, configuring MySQL to listen on a private IP address improves security and reduces exposure to public networks. This approach ensures that database connections are restricted to trusted internal systems while maintaining application connectivity. This guide outlines… Continue Reading Configuring MySQL to Listen on a Private IP Address

Introduction In Jenkins, parameterized builds allow users to provide input values before triggering a job. One of the most useful parameters in CI/CD environments is the Choice Parameter, which enables users to select a specific Git branch during the build process. Instead of creating separate Jenkins jobs for different branches… Continue Reading How to Add Choice Parameter in Jenkins Job for Branch Selection

Introduction K6 is an open-source load testing tool used to test the performance and stability of APIs, websites, and applications.It is lightweight, developer-friendly, and uses JavaScript for writing test scripts. K6 helps to: Prerequisites Before installing K6, ensure the following requirements are available: Example test target: Implementation I. K6 Installation… Continue Reading K6 Load Testing Tool – Installation and Sample Test Scripts

Introduction Liquibase is an open-source database change management tool used to track, version, and deploy database schema changes in a structured and controlled way. It is commonly used in DevOps pipelines and CI/CD workflows (Jenkins, GitLab, ArgoCD) to ensure database consistency across development, testing, and production environments. Prerequisites Before installing… Continue Reading Liquibase Installation on Ubuntu 24

Introduction: In Ubuntu 24.04, administrators can temporarily disable or re-enable user access using command-line tools. Locking a user prevents password-based logins without deleting the account or its files. Prerequisites Before proceeding, ensure the following requirements are met: Implementation Use the following command to lock a user account: Command: $ sudo… Continue Reading How to Lock and Unlock a User on Ubuntu 24.04?

Have you ever opened a website and mobile app for the same service and noticed they show different information? Maybe a pass appears on one but not the other, or a session looks available in one place but not elsewhere. These inconsistencies confuse users and slowly reduce trust in the… Continue Reading Resolving App and Website Data Inconsistencies