Developer Builds Self-Healing Multi-AZ AWS Infrastructure, Documents Real Failures

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A developer set out to build a high-availability AWS architecture spanning two Availability Zones, featuring an Application Load Balancer, Auto Scaling EC2 instances, Multi-AZ RDS MySQL, and CloudWatch monitoring. During testing, a connection timeout error turned out to be caused by a browser silently switching the ALB's HTTP URL to HTTPS, not any AWS misconfiguration. A separate issue with blank instance metadata on the web page was traced to Amazon Linux 2023 enforcing IMDSv2 by default, breaking older metadata fetch methods. The project was deliberately stress-tested by intentionally breaking components to verify the system recovered without manual intervention. The experience highlighted that infrastructure debugging often requires questioning client-side assumptions and keeping up with platform-level security defaults.

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ProgrammingDEV Community ·

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ProgrammingDEV Community ·

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