https://dropbox.tech/infrastructure/increasing-magic-pocket-write-throughput-by-removing-our-ssd-cache-disks


In this episode of the backend engineering show I’ll discuss how Dropbox improved their write through put by 20% by removing all their SSDs (yes I was surprised too). DropBox uses an SSD layer as a write-back cache with SMR drives as their backend persistent storage. They changed their model to write directly to the hard drives.


0:00 Intro


2:00 Article Summary


3:00 SMR Drives


6:00 SSD Cache & WriteBack


8:00 Replacing Cache


9:30 Storage Engine Background


14:30 Why did they do it


15:00 The limitation of SSDs & Zoned Namespaces


19:30 Updating the Storage Engine


22:30 Tradeoffs


26:00 Rollout


28:00 Summary