4 ms·
"This entire space is littered with hard to use and/or flawed products." None of the internet facing services actually need a strongly consistent POSIX filesys
by zzzcpan 10y ago
"This entire space is littered with hard to use and/or flawed products."
None of the internet facing services actually need a strongly consistent POSIX filesystem that scales across multiple datacenters and a huge chunk of them won't put up with corresponding latencies of something like that for mere convinience. So the products are not really flawed, they just don't need to do those things.
- convolvatron 10y agothis is right. posix for posix sake shouldn't really be relevant anymore. look at the success of write-once s3. posix semantics were designed to address issues of concurrent access to the same bytes. also, the only standard distributed protocol for posix, nfs, has always had a lot of design and implementation issues. v4 is complex and tries to address some of the consistency issues, but I don't know how successful it is in practice given the limited usage. treating blobs as immutable addressable objects and using other systems for coordination avoids a lot of the pain with caching, consistency, metadata performance, etc. you can layer those things...its a good cut for large scale distributed systems
- jabl 10y agoWell, NFS isn't really cache coherent, and hence not POSIX compliant. Lustre is, but pays for it with an amazingly complicated architecture. I have (somewhat esoteric corner cases, but still) benchmarks that will cause failures within seconds when run against NFS.