Real-World DevOps Guides

Kubernetes supports two main kube-proxy modes: iptables and ipvs. Which one should you use? 1. What is kube-proxy? kube-proxy manages network rules on Kubernetes nodes, allowing communication between services and pods. It can operate in different modes: iptables, ipvs, and userspace (deprecated). 2. iptables Mode Default and widely supported Implements rules using iptables NAT chains Pros: Simpler No extra kernel modules required Easier to debug Cons: Performance degrades with many services Sequential rule processing 3. IPVS Mode Based on Linux IP Virtual Server (part of LVS) Uses a hash table for rules → faster performance Pros: Better performance for large-scale clusters Supports connection-level load balancing algorithms (round-robin, least connections, etc.) Cons: Requires ip_vs kernel modules Slightly more complex setup 4. Switching to IPVS Check kernel support: ...

Overview Node.js has become a leading platform for building scalable and performant backend applications. With its rich ecosystem, multiple frameworks have emerged to simplify development and promote best practices. This article provides a comparison of the most popular Node.js frameworks — their strengths, trade-offs, and use cases. 1. Express.js Pros: Minimal and flexible Huge community and ecosystem Middleware architecture Cons: Lacks built-in structure Manual setup for many things Example: const express = require('express'); const app = express(); app.get('/', (req, res) => res.send('Hello Express!')); app.listen(3000); 2. Koa.js Created by the same team behind Express, Koa aims to be more modern and lightweight. ...

Introduction OpenTelemetry is an open-source observability framework for cloud-native software, providing a set of APIs, libraries, agents, and instrumentation to collect metrics, logs, and traces. It’s a powerful tool for gaining insight into distributed systems and performance bottlenecks. In this article, we’ll walk through what OpenTelemetry is, why you should use it, and how to set it up step-by-step. Why OpenTelemetry? Unified Observability: One standard for logs, metrics, and traces. Vendor-Neutral: Export data to systems like Prometheus, Jaeger, or commercial APMs. Extensible: Support for multiple languages and platforms. Step-by-Step Guide Step 1: Install the Collector Use the OpenTelemetry Collector to receive, process, and export telemetry data. ...

Introduction Jaeger is an open-source end-to-end distributed tracing tool originally developed by Uber Technologies. It is used for monitoring and troubleshooting microservices-based distributed systems. This guide provides a clear overview of how to install and use Jaeger in Kubernetes with practical examples. Why Use Jaeger? Visualize service dependencies and latencies Troubleshoot performance bottlenecks Monitor request paths across microservices Support for OpenTelemetry Prerequisites A running Kubernetes cluster (e.g., Minikube, k3s, GKE, etc.) kubectl configured Helm installed 1. Install Jaeger with Helm helm repo add jaegertracing https://jaegertracing.github.io/helm-charts helm repo update helm install jaeger jaegertracing/jaeger --set query.basePath=/jaeger --set ingress.enabled=true --set ingress.hosts="{jaeger.yourdomain.com}" To expose Jaeger locally: ...

Introduction Choosing the right Java Development Kit (JDK) base image for your containerized Java applications can impact stability, performance, and licensing. In this article, we compare OpenJDK, Zulu, and Eclipse Temurin images. Why the JDK Image Matters The JDK image you use as a base in your Dockerfile can affect: Application compatibility Startup time and memory usage Patch availability and update cadence Security and vendor support Overview of Options 1. OpenJDK The OpenJDK project provides the reference implementation of Java. It’s available as an official Docker image: ...