Change the default value for replication factor in HadoopFileSystem

[kopczynski-9livesdata]

Hey there!

The current implementation of HadoopFileSystem assumes replication 3 by default. The code I'm referring to is here:

filesystem_spec/fsspec/implementations/arrow.py

Line 257 in 8463a6a

replication=3,

It would be better, IMO, to just use this parameter value from the configuration file. So, this would mean setting replication=0 by default.

[martindurant]

just use this parameter value from the configuration file

Where exactly do you think the value can be found? The upstream default is also 3: https://arrow.apache.org/docs/python/generated/pyarrow.fs.HadoopFileSystem.html
Note that 0 would mean, I think, no copy of the data at all, if it is indeed a legal value.