tf.tpu.experimental.Topology

Describes a set of TPU devices.

Compat aliases for migration

tf.compat.v1.tpu.experimental.Topology

tf.tpu.experimental.Topology(
    serialized=None, mesh_shape=None, device_coordinates=None
)

Represents both the shape of the physical mesh, and the mapping between TensorFlow TPU devices to physical mesh coordinates.

Args
`serialized`	A serialized `TopologyProto`, or `None`. If not `None`, the serialized proto is parsed to discover the topology.
`mesh_shape`	A sequence of 4 positive integers, or `None`. If not `None`, the shape of the TPU topology, in number of cores. Ignored if `serialized` is not `None`.
`device_coordinates`	A rank 3 numpy array that describes the mapping from TensorFlow TPU devices to TPU fabric coordinates, or `None`. If specified, array is 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 4-dimensional, with dimensions `(x, y, z, core number)`. This arg is ignored if `serialized is not`None`.

Raises
`ValueError`	If `serialized` does not describe a well-formed topology.
`ValueError`	If `serialized` is `None` and `mesh_shape` is not a sequence of 4 positive integers.
`ValueError`	If `serialized` is `None` and `device_coordinates` is not a rank 3 numpy int32 array that describes a valid coordinate mapping.

Attributes
`device_coordinates`	Describes the mapping from TPU devices to topology coordinates.
`mesh_rank`	Returns the number of dimensions in the mesh.
`mesh_shape`	A rank 1 int32 array describing the shape of the TPU topology.
`missing_devices`	Array of indices of missing devices.
`num_tasks`	Returns the number of TensorFlow tasks in the TPU slice.
`num_tpus_per_task`	Returns the number of TPU devices per task in the TPU slice.

Methods

cpu_device_name_at_coordinates(
    device_coordinates, job=None
)

Returns the CPU device attached to a logical core.

serialized()

Returns the serialized form of the topology.

task_ordinal_at_coordinates(
    device_coordinates
)

Returns the TensorFlow task number attached to device_coordinates.

Args
`device_coordinates`	An integer sequence describing a device's physical coordinates in the TPU fabric.

Returns
Returns the TensorFlow task number that contains the TPU device with those physical coordinates.

tpu_device_name_at_coordinates(
    device_coordinates, job=None
)

Returns the name of the TPU device assigned to a logical core.

tpu_device_ordinal_at_coordinates(
    device_coordinates
)

Returns the TensorFlow device number at device_coordinates.

Args
`device_coordinates`	An integer sequence describing a device's physical coordinates in the TPU fabric.

Returns
Returns the TensorFlow device number within the task corresponding to attached to the device with those physical coordinates.