Change TPU Embedding API to allow passing functions in the initializer rather than keys. This more closely maps to the feature column API.

PiperOrigin-RevId: 281926084
Change-Id: I6f653d048aa0c00940b70a4616dbc63376ab25c2
This commit is contained in:
Bruce Fontaine 2019-11-22 01:50:54 -08:00 committed by TensorFlower Gardener
parent a30111665f
commit 5fb6dcaea8

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@ -32,6 +32,7 @@ from tensorflow.python.framework import ops
from tensorflow.python.ops import array_ops
from tensorflow.python.ops import control_flow_ops
from tensorflow.python.ops import init_ops
from tensorflow.python.ops import math_ops
from tensorflow.python.ops import partitioned_variables
from tensorflow.python.ops import state_ops
from tensorflow.python.ops import variable_scope
@ -49,7 +50,7 @@ INFERENCE = elc.TPUEmbeddingConfiguration.INFERENCE
class TableConfig(
collections.namedtuple('TableConfig', [
'vocabulary_size', 'dimension', 'initializer', 'combiner',
'hot_id_replication', 'learning_rate', 'learning_rate_key'
'hot_id_replication', 'learning_rate', 'learning_rate_fn'
])):
"""Embedding table configuration."""
@ -60,7 +61,7 @@ class TableConfig(
combiner='mean',
hot_id_replication=False,
learning_rate=None,
learning_rate_key=None):
learning_rate_fn=None):
"""Embedding table configuration.
Args:
@ -79,17 +80,16 @@ class TableConfig(
hot_id_replication: If true, enables hot id replication, which can make
embedding lookups faster if there are some hot rows in the table.
learning_rate: float, static learning rate for this table. If
learning_rate and learning_rate_key are both `None`, global
learning_rate and learning_rate_fn are both `None`, global
static learning rate as specified in `optimization_parameters` in
`TPUEmbedding` constructor will be used. `learning_rate_key` must be
`TPUEmbedding` constructor will be used. `learning_rate_fn` must be
`None` if `learning_rate` is not `None.
learning_rate_key: string, use dynamic learning rate of
`learning_rates[learning_rate_key]` for this table, where
`learning_rates` is the second argument of
`generate_send_gradients_op()`. If learning_rate and learning_rate_key
are both `None`, global static learning rate as specified in
`optimization_parameters` in `TPUEmbedding` constructor will be used.
`learning_rate` must be `None` if `learning_rate_key` is not `None.
learning_rate_fn: string, use dynamic learning rate given by the function.
This function function will be passed the current global step. If
learning_rate and learning_rate_fn are both `None`, global static
learning rate as specified in `optimization_parameters` in
`TPUEmbedding` constructor will be used. `learning_rate` must be `None`
if `learning_rate_fn` is not `None.
Returns:
`TableConfig`.
@ -99,7 +99,7 @@ class TableConfig(
ValueError: if `dimension` is not positive integer.
ValueError: if `initializer` is specified and is not callable.
ValueError: if `combiner` is not supported.
ValueError: if `learning_rate` and `learning_rate_key` are both not
ValueError: if `learning_rate` and `learning_rate_fn` are both not
`None`.
"""
if not isinstance(vocabulary_size, int) or vocabulary_size < 1:
@ -117,14 +117,14 @@ class TableConfig(
if combiner not in ('mean', 'sum', 'sqrtn', None):
raise ValueError('Invalid combiner {}'.format(combiner))
if learning_rate is not None and learning_rate_key is not None:
raise ValueError('At most one of learning_rate and learning_rate_key '
if learning_rate is not None and learning_rate_fn is not None:
raise ValueError('At most one of learning_rate and learning_rate_fn '
'can be None; got {} and {}'
.format(learning_rate, learning_rate_key))
.format(learning_rate, learning_rate_fn))
return super(TableConfig, cls).__new__(
cls, vocabulary_size, dimension, initializer, combiner,
hot_id_replication, learning_rate, learning_rate_key)
hot_id_replication, learning_rate, learning_rate_fn)
class FeatureConfig(
@ -694,6 +694,11 @@ class TPUEmbedding(object):
self._optimization_parameters)
self._pipeline_execution_with_tensor_core = (
pipeline_execution_with_tensor_core)
self._learning_rate_fn = list(set(
c.learning_rate_fn for c in self._table_to_config_dict.values()
if c.learning_rate_fn is not None))
self._learning_rate_fn_to_tag = {
fn: id for id, fn in enumerate(self._learning_rate_fn)}
self._config_proto = self._create_config_proto()
@ -767,10 +772,6 @@ class TPUEmbedding(object):
def _create_config_proto(self):
"""Create `TPUEmbeddingConfiguration`."""
self._learning_rate_keys = list(
set(c.learning_rate_key
for c in self._table_to_config_dict.values()
if c.learning_rate_key is not None))
config_proto = elc.TPUEmbeddingConfiguration()
for table in self._table_to_config_dict:
table_descriptor = config_proto.table_descriptor.add()
@ -788,9 +789,9 @@ class TPUEmbedding(object):
parameters = table_descriptor.optimization_parameters
if table_config.learning_rate:
parameters.learning_rate.constant = (table_config.learning_rate)
elif table_config.learning_rate_key:
elif table_config.learning_rate_fn:
parameters.learning_rate.dynamic.tag = (
self._learning_rate_keys.index(table_config.learning_rate_key))
self._learning_rate_fn_to_tag[table_config.learning_rate_fn])
else:
parameters.learning_rate.constant = (
self._optimization_parameters.learning_rate)
@ -1097,14 +1098,13 @@ class TPUEmbedding(object):
def generate_send_gradients_op(self,
feature_to_gradient_dict,
learning_rates=None):
step=None):
"""Send gradient to TPU embedding.
Args:
feature_to_gradient_dict: dict mapping feature names to gradient wrt
activations.
learning_rates: dict mapping from learning rate key to dynamic learning
rate. Defaults to `None`.
step: the current global step, used for dynamic learning rate.
Returns:
SendTPUEmbeddingGradients Op.
@ -1116,9 +1116,8 @@ class TPUEmbedding(object):
raise RuntimeError('Only in training mode gradients need to '
'be sent to TPU embedding; got mode {}.'
.format(self._mode))
if learning_rates is None:
learning_rates = dict()
if step is None and self._learning_rate_fn:
raise ValueError('There are dynamic learning rates but step is None.')
gradients = []
for table in self._table_to_features_dict:
@ -1137,9 +1136,8 @@ class TPUEmbedding(object):
return tpu_ops.send_tpu_embedding_gradients(
inputs=gradients,
learning_rates=[
learning_rates[tag] for tag in self._learning_rate_keys
],
learning_rates=[math_ops.cast(fn(step), dtype=dtypes.float32)
for fn in self._learning_rate_fn],
config=self.config_proto.SerializeToString())