A distributed Posix file system built on top of Redis and S3

I appreciate the effort to make JuiceFS Posix-compliant first and then compatible with things like Kubernetes down the road.

What are the costs / tradeoffs of this (vs the normal application-layer object storage paradigm)?

Interesting, I’d guess list operations are significantly faster because of the cache, even a hash map like Redis? That can be a real slowdown in s3 with large quantities of files.

Presumably this would be useful if you have apps that currently expect a posix fs since not all (maybe a majority even) of apps don’t run on the cloud. I imagine it’s a drop in replacement for NFS.

Cloud storage access control and data lifecycle control is much more advanced which is something you would probably have to give up with this. Eg IAM restrictions per bucket/object, lifecycle policies etc.

If you’re writing new apps, I don’t see why you would want to add another abstraction layer rather than access cloud storage directly except for very specific use cases.

Would not an NFS solution have this kind of caching and durability built-in? Without doing actual “Jepsen tests” (they are almost a generic term at this point due to their name) how would this improve my life versus buying an NFS vendor solution, or rolling my own?