I can understand that The naming is confusing because MemoryStateBackend is basically a heap based backend, checkpointing to memory and FsStateBackend is a heap based backend checkpointing to a (distributed) filesystem.
Yep, this isn't a problem. I was confused by the HeapKeyedStateBackend ...
MemoryStateBackend and FsStateBackend are those backends operating on the heap. What else do you think is missing?
I can't find the HeapKeyedStateBackend under https://ci.apache.org/projects/flink/flink-docs-release-1.3/ops/state_backends.html.
The issue is not very specific, so I think this is not an issue anymore.
Is this still an issue Stefan Richter?