DevOps

Building an Ultra-Lightweight Cloud-Native Observability & Analytics Stack: Metrics, Logs, Traces & Status on OCI

Running a complex fleet of microservices—spanning AI document assistants, vector databases, lossless audio streamers, private DNS resolvers, and astronomical APIs—demands complete, real-time visibility. But traditional enterprise observability suites (Elasticsearch, heavy Prometheus clusters, DataDog) frequently devour gigabytes of memory and CPU cycles just to monitor a small infrastructure. In this deep dive, I break down how we architected and deployed a complete, ultra-lightweight, 360-degree Observability, Logging, Analytics, and Uptime Stack across our 3-node hybrid cloud fleet at vinhthang.dev, maintaining sub-millisecond query latencies while consuming less than 250 MB total RAM! ...

How to Snag the Elusive Oracle Cloud Always Free ARM64 Ampere A1 Instance

If you have ever tried to launch an ARM64 Ampere A1 Flex compute instance on Oracle Cloud Infrastructure (OCI) Always Free, you have almost certainly encountered this dreaded error message: 500-InternalError: Out of host capacity for shape VM.Standard.A1.Flex in availability domain... Oracle’s Always Free tier offers one of the most generous compute allowances in the industry—up to 4 OCPUs and 24 GB RAM on enterprise-grade Ampere Altra ARM64 processors. Because of this, capacity in popular data centers (like Tokyo, Seoul, Ashburn, Frankfurt, and Singapore) is constantly saturated. ...

Autonomous AI Infrastructure: AnythingLLM, PostgreSQL 18 pgvector, and the Antigravity CLI (agy) System Agent

Most self-hosted AI setups stop at running a basic chat UI connected to a remote API. But what if your self-hosted AI wasn’t just a conversational bot, but a fully empowered autonomous system agent capable of managing your infrastructure, installing command-line tools, debugging services, and querying custom vector databases? In this post, I will explore our complete self-hosted AI architecture running on an Always Free cloud Kubernetes cluster—featuring AnythingLLM, PostgreSQL 18 with pgvector, and the Google Antigravity CLI (agy). ...

Architecting a Multi-Node Hybrid K3s Kubernetes Fleet on Oracle Cloud Always Free

How do you turn 3 separate Always Free cloud virtual machines into a resilient, production-grade, multi-architecture Kubernetes cluster capable of running high-performance relational databases, AI vector stores, lossless music streaming, and personal cloud storage? In this post, I will break down the complete architecture of our newly deployed 3-Node Hybrid K3s Cluster running on Oracle Cloud Infrastructure (OCI) under our custom domain vinhthang.dev. 🏛️ The 3-Node Cluster Topology Oracle Cloud’s Always Free tier offers an incredible set of compute resources: ...