Do not create parent directory if it exists
Do not create parent directory if it exists

If parent directories do not exist, this costs one more round trip. But
as most metrics have siblings, this saves time overall.

Thib17/biggraphite,iksaif/biggraphite,criteo/biggraphite,criteo/biggraphite,Thib17/biggraphite,dpanth3r/biggraphite,criteo/biggraphite,iksaif/biggraphite,iksaif/biggraphite,unbrice/biggraphite,iksaif/biggraphite,Thib17/biggraphite,Thib17/biggraphite,criteo/biggraphite,natbraun/biggraphite