DB keys TTL and hdf5 files
When keys are deleted from redis, the hdf5 filename is reset; this is fine in most cases however it can lead to errors if user collects data one day, does something else, come back to the exact same directory etc. the day after and wants to append in the previous hdf5 file.
This is not so often but it can happen !
A possible solution is to have different TTLs, like one week or more for scan keys...
finally we resynchronise with the file