tf.contrib.all_reduce.build_nccl_then_ring

tf.contrib.all_reduce.build_nccl_then_ring(
    input_tensors,
    subdiv,
    red_op,
    un_op=None
)

Defined in tensorflow/contrib/all_reduce/python/all_reduce.py.

Construct hybrid of NCCL within workers, Ring across workers.