Unintended double encryption crippled our search engine performance (opens in new tab)

Seems like pretty poor documentation by Azure. Encryption and performance are such key architecture concerns, they should be promoting the automatic hardware-based disk encryption as a security and performance feature. Looking at the updated docs, they still don't seem very clear to me.

Great story! Successful cloud performance investigations are always extremely satisfying. I love this conclusion:

It’s a reminder that sometimes performance bottlenecks are hard to diagnose, but with careful debugging, good data, and collaboration with providers, even cloud-level issues can be resolved.