def _get_checkpoint_filename(ckpt_dir_or_file):
"""Returns checkpoint filename given directory or specific checkpoint file."""
if isinstance(ckpt_dir_or_file, os.PathLike):
ckpt_dir_or_file = os.fspath(ckpt_dir_or_file)
if gfile.IsDirectory(ckpt_dir_or_file):
return checkpoint_management.latest_checkpoint(ckpt_dir_or_file)
return ckpt_dir_or_file
def wait_for_new_checkpoint(checkpoint_dir,
last_checkpoint=None,
seconds_to_sleep=1,
timeout=None):
"""Waits until a new checkpoint file is found.
Args:
checkpoint_dir: The directory in which checkpoints are saved.
last_checkpoint: The last checkpoint path used or `None` if we're expecting
a checkpoint for the first time.
seconds_to_sleep: The number of seconds to sleep for before looking for a
new checkpoint.
timeout: The maximum number of seconds to wait. If left as `None`, then the
process will wait indefinitely.
Returns:
a new checkpoint path, or None if the timeout was reached.
"""
logging.info("Waiting for new checkpoint at %s", checkpoint_dir)
stop_time = time.time() + timeout if timeout is not None else None
while True:
checkpoint_path = checkpoint_management.latest_checkpoint(checkpoint_dir)
if checkpoint_path is None or checkpoint_path == last_checkpoint:
if stop_time is not None and time.time() + seconds_to_sleep > stop_time:
return None
time.sleep(seconds_to_sleep)
else:
logging.info("Found new checkpoint at %s", checkpoint_path)
return checkpoint_path
def test_spmd_model_checkpointing(self):
class LinearModel(module.Module):
def __init__(self, w):
super(LinearModel, self).__init__()
self.w = variables.Variable(w)
def __call__(self, x):
return math_ops.matmul(x, self.w)
def change_weights_op(self, w_new):
return self.w.assign(w_new)
batch_size = 32
num_feature_in = 16
num_feature_out = 8
w1 = random_ops.random_uniform((num_feature_in, num_feature_out),
dtype=dtypes.float32)
w2 = random_ops.random_uniform((num_feature_in, num_feature_out),
dtype=dtypes.float32)
x = random_ops.random_uniform((batch_size, num_feature_in),
dtype=dtypes.float32)
strategy, num_replicas = get_tpu_strategy(enable_spmd=True)
with strategy.scope():
model = LinearModel(w1)
checkpoint_dir = self.get_temp_dir()
checkpoint_prefix = os.path.join(checkpoint_dir, "ckpt")
checkpoint = util.Checkpoint(model=model)
@def_function.function
def step_fn(x):
x = strategy.experimental_split_to_logical_devices(x, [1, 2])
return model(x)
with self.cached_session() as sess:
self.evaluate(variables.global_variables_initializer())
checkpoint.save(file_prefix=checkpoint_prefix)
self.evaluate(model.change_weights_op(w2))
result = strategy.run(step_fn, args=(x,))
self.assertAllClose(
math_ops.matmul(x, w2) * num_replicas,
self.evaluate(strategy.reduce("SUM", result, axis=None)),
rtol=5e-3,
atol=5e-3)
status = checkpoint.restore(
checkpoint_management.latest_checkpoint(checkpoint_dir))
status.run_restore_ops(sess) # must run restore op in non-eager mode.
status.assert_consumed()
status.assert_existing_objects_matched()
result = strategy.run(step_fn, args=(x,))
self.assertAllClose(
math_ops.matmul(x, w1) * num_replicas,
self.evaluate(strategy.reduce("SUM", result, axis=None)),
rtol=5e-3,
atol=5e-3)
def _restore_or_save_initial_ckpt(self, session):
# Ideally this should be run in after_create_session but is not for the
# following reason:
# Currently there is no way of enforcing an order of running the
# `SessionRunHooks`. Hence it is possible that the `_DatasetInitializerHook`
# is run *after* this hook. That is troublesome because
# 1. If a checkpoint exists and this hook restores it, the initializer hook
# will override it.
# 2. If no checkpoint exists, this hook will try to save an uninitialized
# iterator which will result in an exception.
#
# As a temporary fix we enter the following implicit contract between this
# hook and the _DatasetInitializerHook.
# 1. The _DatasetInitializerHook initializes the iterator in the call to
# after_create_session.
# 2. This hook saves the iterator on the first call to `before_run()`, which
# is guaranteed to happen after `after_create_session()` of all hooks
# have been run.
# Check if there is an existing checkpoint. If so, restore from it.
# pylint: disable=protected-access
latest_checkpoint_path = checkpoint_management.latest_checkpoint(
self._checkpoint_saver_hook._checkpoint_dir,
latest_filename=self._latest_filename)
if latest_checkpoint_path:
self._checkpoint_saver_hook._get_saver().restore(
session, latest_checkpoint_path)
else:
# The checkpoint saved here is the state at step "global_step".
# Note: We do not save the GraphDef or MetaGraphDef here.
global_step = session.run(
self._checkpoint_saver_hook._global_step_tensor)
self._checkpoint_saver_hook._save(session, global_step)
self._checkpoint_saver_hook._timer.update_last_triggered_step(
global_step)
def testLatestCheckpointFSpathDirectory(self):
directory = pathlib.Path(self.get_temp_dir())
checkpoint = util.Checkpoint()
manager = checkpoint_management.CheckpointManager(
checkpoint, directory, max_to_keep=2, checkpoint_name="ckpt_name")
manager.save()
cp_dir = checkpoint_management.latest_checkpoint(directory)
self.assertEqual(str(directory / "ckpt_name-1"), cp_dir)
def _read_vars(self, model_dir):
"""Returns (global_step, latest_feature)."""
with ops.Graph().as_default() as g:
ckpt_path = checkpoint_management.latest_checkpoint(model_dir)
meta_filename = ckpt_path + '.meta'
saver_lib.import_meta_graph(meta_filename)
saver = saver_lib.Saver()
with self.session(graph=g) as sess:
saver.restore(sess, ckpt_path)
return sess.run(ops.get_collection('my_vars'))
def test_paritioned_model_checkpointing(self):
class PartitionedModel(module.Module):
def __init__(self, v, w):
super(PartitionedModel, self).__init__()
assert distribution_strategy_context.has_strategy()
strategy = distribution_strategy_context.get_strategy()
with strategy.extended.experimental_logical_device(0):
self.v = variables.Variable(v)
with strategy.extended.experimental_logical_device(1):
self.w = variables.Variable(w)
def __call__(self, x):
replica_ctx = distribution_strategy_context.get_replica_context(
)
with replica_ctx.experimental_logical_device(0):
y = self.v * x
with replica_ctx.experimental_logical_device(1):
z = self.w * y
return z
def change_weights_op(self, v_new, w_new):
return control_flow_ops.group(
[self.v.assign(v_new),
self.w.assign(w_new)])
strategy, num_replicas = get_tpu_strategy()
with strategy.scope():
model = PartitionedModel(2., 3.)
checkpoint_dir = self.get_temp_dir()
checkpoint_prefix = os.path.join(checkpoint_dir, "ckpt")
checkpoint = util.Checkpoint(model=model)
with self.cached_session() as sess:
self.evaluate(variables.global_variables_initializer())
checkpoint.save(file_prefix=checkpoint_prefix)
self.evaluate(model.change_weights_op(1., 4.))
result = strategy.run(def_function.function(model), args=(5.0, ))
self.assertEqual(
20. * num_replicas,
self.evaluate(strategy.reduce("SUM", result, axis=None)))
status = checkpoint.restore(
checkpoint_management.latest_checkpoint(checkpoint_dir))
status.run_restore_ops(
sess) # must run restore op in non-eager mode.
status.assert_consumed()
status.assert_existing_objects_matched()
result = strategy.run(def_function.function(model), args=(5.0, ))
self.assertEqual(
30. * num_replicas,
self.evaluate(strategy.reduce("SUM", result, axis=None)))
def testRestoreInReconstructedIteratorInitializable(self):
checkpoint_directory = self.get_temp_dir()
checkpoint_prefix = os.path.join(checkpoint_directory, "ckpt")
dataset = dataset_ops.Dataset.range(10)
iterator = iter(dataset)
get_next = iterator.get_next
checkpoint = trackable_utils.Checkpoint(iterator=iterator)
for i in range(5):
checkpoint.restore(
checkpoint_management.latest_checkpoint(
checkpoint_directory)).initialize_or_restore()
for j in range(2):
self.assertEqual(i * 2 + j, self.evaluate(get_next()))
checkpoint.save(file_prefix=checkpoint_prefix)
def testNameCollision(self):
# Make sure we have a clean directory to work in.
with self.tempDir() as tempdir:
# Jump to that directory until this test is done.
with self.tempWorkingDir(tempdir):
# Save training snapshots to a relative path.
traindir = "train"
os.mkdir(traindir)
# Collides with the default name of the checkpoint state file.
filepath = os.path.join(traindir, "checkpoint")
with self.cached_session() as sess:
unused_a = variables.Variable(
0.0) # So that Saver saves something.
self.evaluate(variables.global_variables_initializer())
# Should fail.
saver = saver_module.Saver(sharded=False)
with self.assertRaisesRegex(ValueError, "collides with"):
saver.save(sess, filepath)
# Succeeds: the file will be named "checkpoint-<step>".
saver.save(sess, filepath, global_step=1)
self.assertIsNotNone(
checkpoint_management.latest_checkpoint(traindir))
# Succeeds: the file will be named "checkpoint-<i>-of-<n>".
saver = saver_module.Saver(sharded=True)
saver.save(sess, filepath)
self.assertIsNotNone(
checkpoint_management.latest_checkpoint(traindir))
# Succeeds: the file will be named "checkpoint-<step>-<i>-of-<n>".
saver = saver_module.Saver(sharded=True)
saver.save(sess, filepath, global_step=1)
self.assertIsNotNone(
checkpoint_management.latest_checkpoint(traindir))
def testRelativePath(self):
# Make sure we have a clean directory to work in.
with self.tempDir() as tempdir:
# Jump to that directory until this test is done.
with self.tempWorkingDir(tempdir):
# Save training snapshots to a relative path.
traindir = "train"
os.mkdir(traindir)
filename = "snapshot"
filepath = os.path.join(traindir, filename)
with self.cached_session() as sess:
# Build a simple graph.
v0 = variables.Variable(0.0)
inc = v0.assign_add(1.0)
save = saver_module.Saver({"v0": v0})
# Record a short training history.
self.evaluate(variables.global_variables_initializer())
save.save(sess, filepath, global_step=0)
self.evaluate(inc)
save.save(sess, filepath, global_step=1)
self.evaluate(inc)
save.save(sess, filepath, global_step=2)
with self.cached_session() as sess:
# Build a new graph with different initialization.
v0 = variables.Variable(-1.0)
# Create a new saver.
save = saver_module.Saver({"v0": v0})
self.evaluate(variables.global_variables_initializer())
# Get the most recent checkpoint name from the training history file.
name = checkpoint_management.latest_checkpoint(traindir)
self.assertIsNotNone(name)
# Restore "v0" from that checkpoint.
save.restore(sess, name)
self.assertEqual(v0.eval(), 2.0)
def testCheckpointExists(self):
for sharded in (False, True):
for version in (saver_pb2.SaverDef.V2, saver_pb2.SaverDef.V1):
with self.session(graph=ops_lib.Graph()) as sess:
unused_v = variables.Variable(1.0, name="v")
self.evaluate(variables.global_variables_initializer())
saver = saver_module.Saver(sharded=sharded,
write_version=version)
path = os.path.join(self._base_dir,
"%s-%s" % (sharded, version))
self.assertFalse(
checkpoint_management.checkpoint_exists(
path)) # Not saved yet.
ckpt_prefix = saver.save(sess, path)
self.assertTrue(
checkpoint_management.checkpoint_exists(ckpt_prefix))
ckpt_prefix = checkpoint_management.latest_checkpoint(
self._base_dir)
self.assertTrue(
checkpoint_management.checkpoint_exists(ckpt_prefix))
def testCustomNumbering(self):
directory = self.get_temp_dir()
step = variables.Variable(0, dtype=dtypes.int64)
checkpoint = util.Checkpoint(step=step)
manager = checkpoint_management.CheckpointManager(checkpoint,
directory,
max_to_keep=2)
self.evaluate(step.initializer)
for i in range(5):
path = manager.save(checkpoint_number=step)
expected_suffix = "-%d" % (2 * i, )
if not path.endswith(expected_suffix):
self.fail("%s should have suffix %s" % (path, expected_suffix))
self.evaluate(step.assign_add(2))
self.assertEqual(5, self.evaluate(checkpoint.save_counter))
# Test regular integers
last_path = manager.save(checkpoint_number=32)
self.assertIn("-32", last_path)
self.assertEqual(last_path, manager.latest_checkpoint)
self.assertEqual(last_path,
checkpoint_management.latest_checkpoint(directory))
state = checkpoint_management.get_checkpoint_state(directory)
# Only the most recent two checkpoints are saved
self.assertEqual([path, last_path], state.all_model_checkpoint_paths)
def _latest_ckpt(self):
return checkpoint_management.latest_checkpoint(self.get_temp_dir())
