#DevOps

A 100M-event CDM in production behaves nothing like the Eunomia sample. This article covers schema design, indexing, partitioning by person_id, vacuum, backup, security under Vietnam's Personal Data Protection Law 2025 (effective Jan 1, 2026), audit logging, and vocabulary upgrades.

Duy TranMay 7, 202614 min

ETL from a HIS/EHR/claims source to OMOP CDM takes 3-6 months from scratch. This article walks through the OHDSI standard pipeline: WhiteRabbit profiling, RabbitInAHat design, USAGI mapping, implementation with SQL/Perseus/dbt, and validation with DQD.

Duy TranMay 7, 202618 min

Instructions for installing KVM on Ubuntu and managing VM via Cockpit Web UI. Configure network bridge, NAT virtual network, storage pool for 2 node homelab.

Duy TranDecember 25, 202527 min

Learn Circuit Breaker Pattern in Spring Boot with Resilience4j - from operating principles, detailed configuration, practical examples to best practices. A complete guide to help you build resilient microservices systems, prevent cascading failures and automatically recover when services encounter problems.

Duy TranDecember 23, 202535 min

Detailed instructions for upgrading PostgreSQL 17.6 to 18.1 for production environments with minimal downtime. Includes pg_upgrade, logical replication, rollback plan, and updated best practices for PostgreSQL 18 with Async I/O, Statistics Preservation, and new pg_upgrade --swap mode.

Duy TranDecember 23, 202515 min

This article will help you master PostgreSQL backup and restore methods from basic to advanced, along with practical best practices.

Duy TranDecember 8, 202513 min

Detailed instructions for installing Harbor - private Docker registry on Ubuntu 24.04, including HTTPS, security, backup and best practices.

Duy TranDecember 2, 202510 min

Share experience in deploying and open-source fully automated PostgreSQL HA cluster solution

Duy TranNovember 25, 202514 min

Detailed instructions on how to install KVM (Kernel-based Virtual Machine) on Ubuntu 24.04 LTS with Cockpit or Kimchi web management interface. Learn how to set up a complete virtualization environment, configure a network bridge, and create your first virtual machine with ease.

Duy TranNovember 24, 20259 min

A comprehensive course on VyOS — a powerful open-source network operating system. From installation and basic configuration to firewall, VPN, advanced routing (BGP/OSPF), High Availability, VLANs, WireGuard, and real-world production deployment.

A comprehensive study guide for the CKA (Certified Kubernetes Administrator) exam. Covers all 5 hands-on domains: Troubleshooting (30%), Cluster Architecture (25%), Services & Networking (20%), Workloads & Scheduling (15%), Storage (10%). 12 lessons with hands-on terminal exercises.

A comprehensive study roadmap for the CKAD (Certified Kubernetes Application Developer) exam. Fully covers all 5 hands-on domains: App Environment & Security (25%), App Design & Build (20%), App Deployment (20%), Services & Networking (20%), App Observability (15%). 10 lessons with hands-on terminal exercises.

A comprehensive study path for the KCNA (Kubernetes and Cloud Native Associate) exam. Covers all 5 domains: Kubernetes Fundamentals (46%), Container Orchestration (22%), Cloud Native Architecture (16%), Observability (8%), Application Delivery (8%). 9 in-depth lessons with English practice quizzes.

A hands-on series on building a complete Microservices system with Quarkus 3.x — the "Supersonic Subatomic" Java framework designed specifically for Cloud Native and Kubernetes. Using PostgreSQL as main database, Keycloak for Authentication & Authorization (OIDC), Apache Kafka for Event-Driven Communication, gRPC for high-performance inter-service. From creating your first project with Dev Services, building a REST API with Panache, to deploying production on Kubernetes with GraalVM Native Image. Includes Fault Tolerance, OpenTelemetry Observability, Contract Testing, CI/CD Pipeline and Production Readiness Checklist. Actual project: E-Commerce Platform system includes 5 microservices.

Comprehensive practical course on deploying Microservices on-premises systems using Kubernetes HA (High Availability), PostgreSQL HA with Patroni, Ceph/Rook storage, Istio Service Mesh, ArgoCD GitOps, Prometheus Observability Stack, HashiCorp Vault, RabbitMQ HA, Redis Cluster and many other production-grade technologies. From infrastructure design, cluster installation, microservices deployment to operations, DR and enterprise standard security. 50 lessons + practice labs on bare-metal/VM.

Comprehensive series on Cloud Native Microservices architecture — from container platforms, Kubernetes, microservices design principles (DDD, Bounded Context), communication models (REST, gRPC, Event-Driven), to Data Management (CQRS, Saga, Event Sourcing), Service Mesh, Observability, Resiliency Patterns, CI/CD GitOps and Security. Combine solid theory with practical architecture for production systems.

The HashiCorp Vault course is comprehensive from basic to advanced, helping you master Secret Management, Encryption as a Service, Dynamic Credentials and Identity-based Security. From installing and configuring Secrets Engines (KV, PKI, Transit, Database, AWS, SSH), Auth Methods (Token, Userpass, AppRole, LDAP, OIDC, Kubernetes), Policies, to advanced topics such as Integrated Storage (Raft), High Availability, Auto-unseal, Vault Agent, Vault Secrets Operator, Enterprise features (Namespaces, Sentinel, Replication, DR), monitoring and production operations. Updated to Vault 1.21.x (latest version 2026), including SPIFFE auth, MFA TOTP self-enrollment, KV v2 version attribution and enterprise security best practices.

The Keycloak course is comprehensive from basic to advanced, helping you master Identity and Access Management (IAM) from installing and configuring Realms, Users, Roles, Clients, to advanced modules such as Identity Brokering, User Federation (LDAP/AD), Authentication Flows, Authorization Services, Multi-Factor Authentication, Organizations, Workflows, Passkeys, and integrating with real applications. Updated to Keycloak 26.x (latest version 2026) running on Quarkus, including production operations, High Availability, Kubernetes Operators and enterprise security best practices.

Comprehensive course on Performance Testing and Penetration Testing according to enterprise standards 2026. From processes, tools, implementation to professional reports. Includes k6, Gatling, Artillery, Burp Suite, Nuclei, OWASP ZAP, Metasploit, Cloud/Kubernetes security testing, AI-powered testing, CVSS v4.0, PTES, OWASP Top 10, Chaos Engineering, SRE practices and compliance frameworks. Practical combat instructions with lab exercises and real-world scenarios.

Comprehensive Docker course from fundamentals to advanced level, helping you master container technology from the first concepts to real-world production deployment. Covers Dockerfile, Docker Compose, Networking, Storage, Security, CI/CD, Docker Swarm, Microservices and best practices for enterprise environments. Updated with Docker Engine 27+ and modern container technologies as of 2026.

Comprehensive basic to advanced Kubernetes course for 2026, helping you master container orchestration, deploy production-ready applications, and prepare for CKA/CKAD certification. Updated to Kubernetes 1.32+ with Gateway API, Cilium, OpenTelemetry, Helm 4, Sidecar containers GA, ValidatingAdmissionPolicy, and AI/ML workloads.

Nginx Master Course: From Zero to Hero is a comprehensive course that helps you master Nginx from the most fundamental concepts to advanced techniques in real-world production environments.

Learn how to deploy PostgreSQL High Availability cluster with Patroni and etcd. Practical course from A-Z: installation, configuration, automatic failover, monitoring and production operations. 29 lessons + detailed labs.