Describes a set of TPU devices.
Represents both the shape of the physical mesh, and the mapping between TensorFlow TPU devices to physical mesh coordinates.
__init__( serialized=None, mesh_shape=None, device_coordinates=None )
Builds a Topology object.
serialized is not
None, the topology is parsed from
the other arguments are ignored. Otherwise, the topology is computed from
serialized: A serialized
None. If not
None, the serialized proto is parsed to discover the topology.
mesh_shape: A sequence of 3 positive integers, or
None. If not
None, the shape of the TPU topology, in number of cores. Ignored if
device_coordinates: A rank 3 numpy array that describes the mapping from TensorFlow TPU devices to TPU fabric coordinates, or
None. Ignored if
serialized is notNone`.
serializeddoes not describe a well-formed topology.
mesh_shapeis not a sequence of 3 positive integers.
device_coordinatesis not a rank 3 numpy int32 array that describes a valid coordinate mapping.
Describes the mapping from TPU devices to topology coordinates.
A rank 3 int32 array with shape
[tasks, devices, axis].
tasks is the number of tasks in the TPU cluster,
devices is the number
of TPU devices per task, and
axis is the number of axes in the TPU
cluster topology. Each entry gives the
axis-th coordinate in the
topology of a task/device pair. TPU topologies are 3-dimensional, with
(x, y, core number).
A rank 1 int32 array describing the shape of the TPU topology.
Returns the serialized form of the topology.