This article outlines the implementation and usage of custom Apache 503 error pages on production Tomcat web application instances

Network troubleshooting and configuration are crucial skills for Linux system administrators. This guide covers essential network commands for AlmaLinux/RHEL systems.

On Friday 6th September 2024 at 21:31, we received an alert from LogicMonitor indicating one of our production web app servers (Tomcat#3) was down, with the message: "The host Tomcat#3 (i-xxxxxxx) is down". However, shortly after receiving the alert, we attempted to SSH into the VM and confirmed that the server was fully operational. But what did it go wrong?

In this guide, I'll demonstrate a blue-green deployment strategy in Kubernetes using Deployments and Services. The goal is to achieve zero downtime by running two sets of pods: the current version (v1.0, blue) and the new version (v2.0, green). I'll also explain how to roll back from green to blue if necessary.

On 15th August 2024, an incident occurred where the CPUBusyPercent alert did not trigger for one of our Production MySQL Database VMs (DB01), despite the CPU being at 100% for seven minutes. This was unexpected since the threshold settings in LogicMonitor were supposed to trigger alerts under such conditions.

Logrotate helps manage log files by automatically rotating, compressing, and removing them when they become too large or outdated, preventing excessive disk space usage and ensuring system stability.

This project showcases an end-to-end DevOps pipeline for deploying a basic Flask application using Jenkins Pipeline and GitOps (with ArgoCD) on an Amazon Elastic Kubernetes Service (EKS) cluster.

This project demonstrates building a basic REST API in Golang, implementing CRUD operations with a PostgreSQL database for data persistence. The application utilises Gorilla Mux for routing, PostgreSQL for the database, and Docker for containerisation.