Alibaba Cloud Full Stack (4): OSS — Object Storage Done Right

Fri, 01 May 2026 09:00:00 +0000

I used to store user uploads on the ECS disk. Profile pictures, PDF invoices, CSV exports — all dumped into /var/data/uploads/ on a single ecs.g7.large running my Flask app. I had a cron job that rsynced the directory to a second ECS instance every six hours as a “backup.” Then one Friday at 3am, the system disk hit 100% because a batch job generated 40GB of reports nobody ever downloaded, the instance went read-only, the app crashed, and the rsync hadn’t run since the previous evening. I lost six hours of user uploads and spent the weekend apologizing to customers. That was the week I learned that object storage is not a nice-to-have — it is the foundation of everything you build in the cloud. Your application server is ephemeral. Your data is not.

System Design (2): DNS, CDN, and Load Balancing — The First Three Hops

Sat, 12 Jul 2025 09:00:00 +0000

In 2017, a single misconfigured DNS record at a major cloud provider took down a significant portion of the internet for several hours. Thousands of websites became unreachable — not because their servers were down, but because the system that translates domain names into IP addresses stopped working correctly. The incident was a stark reminder that the infrastructure we take for granted — DNS, CDN, load balancers — is the foundation everything else rests on.

CDN on Chen Kai Blog

Alibaba Cloud Full Stack (4): OSS — Object Storage Done Right

System Design (2): DNS, CDN, and Load Balancing — The First Three Hops