Classification: Operational Lifecycle & Database Resilience
Status: Implemented & Verified
Executive Summary
This report documents the failure modes, triage, and safe maintenance patterns discovered while updating multi-container microservice stacks with tightly coupled database dependencies. It analyzes race conditions during parallel image layer pulls, container recreations vs. image caching, and ensuring zero data loss during automated backend schema migrations.
The Problem Statement & Failure Modes
Updating production-grade container stacks (such as Firefly III, its importer, cron sidecar, and MariaDB/MySQL backend) presents subtle operational risks if treated like simple stateless containers: