Needs to be 600.
@s-u, somehow files created with rcloud.upload.create.file have 666 permissions, but files created on a default interactive R prompt have 644 permission. What could be going on?
It is governed by umask and the default in Rserve is 0000 (unfortunately). So all it needs is probably this line in Rserve.conf:
use more restrictive umask - closes #136