This article explains diagnostic commands based on Finite State Machine (FSM) transition states, identification flows for the 7 major root causes, and proactive design using BFD for rapid recovery during BGP session disconnections.
A technical guide for backend engineers covering the OSI 7-layer model, the evolution from HTTP/1.1 to HTTP/3, DNS resolution flows, the operating principles of reverse proxies and L4/L7 load balancers, and the end-to-end request lifecycle.
Explains the technical differences, security characteristics, and the constraint of mutual exclusivity within the same runner for Docker-in-Docker (DinD) and Docker-out-of-Docker (DooD) in GitLab CI/CD environments.
Technical specifications for SNS development using Spring Boot 3.3 and React. Explains the roadmap for building an MVP, including JWT authentication, JPA data models, and feed generation logic.
Technical analysis of B-Tree index internals, storage node layout, and query performance optimization strategies for enterprise infrastructure.
A technical explanation of the evolutionary process of Python web interfaces (CGI, WSGI, ASGI), modern WAS configurations using Gunicorn and Uvicorn, and architectural differences between Django and FastAPI.
Explains the procedures for identifying and removing orphaned GIDs in Linux /etc/group that do not have corresponding user accounts. Provides a practical diagnostic script and remediation workflow based on security audit vulnerability assessment item [U-09].
Provides a comparative analysis of REST, GraphQL, gRPC, and WebSocket, along with explanations of Saga patterns in MSA, API gateway design, and HTTPS implementation procedures in Spring Boot.
This article explains pre-aggregation table design and Redis caching strategies for aggregating large-scale user activity logs in real time and rendering dashboards with low latency.
A record of initial setup and security hardening procedures for KVM virtualization, DHCP, NTP, NIS/NFS, rsyslog, and Kerberos-based authentication integration on Ubuntu Server.