Files
ray/python/ray/tune/trainable.py
T
Richard Liaw 62d0698097 [tune] Tune Facelift (#2472)
This PR introduces the following changes:

 * Ray Tune -> Tune 
 * [breaking] Creation of `schedulers/`, moving PBT, HyperBand into a submodule
 * [breaking] Search Algorithms now must take in experiment configurations via `add_configurations` rather through initialization
 * Support `"run": (function | class | str)` with automatic registering of trainable
 * Documentation Changes
2018-08-19 11:00:55 -07:00

311 lines
10 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from datetime import datetime
import gzip
import io
import os
import pickle
import shutil
import tempfile
import time
import uuid
import ray
from ray.tune.logger import UnifiedLogger
from ray.tune.result import (DEFAULT_RESULTS_DIR, TIME_THIS_ITER_S,
TIMESTEPS_THIS_ITER, DONE, TIMESTEPS_TOTAL)
from ray.tune.trial import Resources
class Trainable(object):
"""Abstract class for trainable models, functions, etc.
A call to ``train()`` on a trainable will execute one logical iteration of
training. As a rule of thumb, the execution time of one train call should
be large enough to avoid overheads (i.e. more than a few seconds), but
short enough to report progress periodically (i.e. at most a few minutes).
Calling ``save()`` should save the training state of a trainable to disk,
and ``restore(path)`` should restore a trainable to the given state.
Generally you only need to implement ``_train``, ``_save``, and
``_restore`` here when subclassing Trainable.
Note that, if you don't require checkpoint/restore functionality, then
instead of implementing this class you can also get away with supplying
just a ``my_train(config, reporter)`` function to the config.
The function will be automatically converted to this interface
(sans checkpoint functionality).
"""
def __init__(self, config=None, logger_creator=None):
"""Initialize an Trainable.
Sets up logging and points ``self.logdir`` to a directory in which
training outputs should be placed.
Subclasses should prefer defining ``_setup()`` instead of overriding
``__init__()`` directly.
Args:
config (dict): Trainable-specific configuration data. By default
will be saved as ``self.config``.
logger_creator (func): Function that creates a ray.tune.Logger
object. If unspecified, a default logger is created.
"""
self._initialize_ok = False
self._experiment_id = uuid.uuid4().hex
self.config = config or {}
if logger_creator:
self._result_logger = logger_creator(self.config)
self.logdir = self._result_logger.logdir
else:
logdir_prefix = datetime.today().strftime("%Y-%m-%d_%H-%M-%S")
if not os.path.exists(DEFAULT_RESULTS_DIR):
os.makedirs(DEFAULT_RESULTS_DIR)
self.logdir = tempfile.mkdtemp(
prefix=logdir_prefix, dir=DEFAULT_RESULTS_DIR)
self._result_logger = UnifiedLogger(self.config, self.logdir, None)
self._iteration = 0
self._time_total = 0.0
self._timesteps_total = 0
self._setup()
self._initialize_ok = True
self._local_ip = ray.services.get_node_ip_address()
@classmethod
def default_resource_request(cls, config):
"""Returns the resource requirement for the given configuration.
This can be overriden by sub-classes to set the correct trial resource
allocation, so the user does not need to.
"""
return Resources(cpu=1, gpu=0)
@classmethod
def resource_help(cls, config):
"""Returns a help string for configuring this trainable's resources."""
return ""
def train(self):
"""Runs one logical iteration of training.
Subclasses should override ``_train()`` instead to return results.
This class automatically fills the following fields in the result:
`done` (bool): training is terminated. Filled only if not provided.
`time_this_iter_s` (float): Time in seconds this iteration
took to run. This may be overriden in order to override the
system-computed time difference.
`time_total_s` (float): Accumulated time in seconds for this
entire experiment.
`experiment_id` (str): Unique string identifier
for this experiment. This id is preserved
across checkpoint / restore calls.
`training_iteration` (int): The index of this
training iteration, e.g. call to train().
`pid` (str): The pid of the training process.
`date` (str): A formatted date of when the result was processed.
`timestamp` (str): A UNIX timestamp of when the result
was processed.
`hostname` (str): Hostname of the machine hosting the training
process.
`node_ip` (str): Node ip of the machine hosting the training
process.
Returns:
A dict that describes training progress.
"""
if not self._initialize_ok:
raise ValueError(
"Trainable initialization failed, see previous errors")
start = time.time()
result = self._train()
result = result.copy()
self._iteration += 1
if result.get(TIME_THIS_ITER_S) is not None:
time_this_iter = result[TIME_THIS_ITER_S]
else:
time_this_iter = time.time() - start
self._time_total += time_this_iter
self._timesteps_total += result.get(TIMESTEPS_THIS_ITER, 0)
result.setdefault(DONE, False)
result.setdefault(TIMESTEPS_TOTAL, self._timesteps_total)
# Provides auto-filled neg_mean_loss for avoiding regressions
if result.get("mean_loss"):
result.setdefault("neg_mean_loss", -result["mean_loss"])
now = datetime.today()
result.update(
experiment_id=self._experiment_id,
date=now.strftime("%Y-%m-%d_%H-%M-%S"),
timestamp=int(time.mktime(now.timetuple())),
training_iteration=self._iteration,
time_this_iter_s=time_this_iter,
time_total_s=self._time_total,
pid=os.getpid(),
hostname=os.uname()[1],
node_ip=self._local_ip,
config=self.config)
self._result_logger.on_result(result)
return result
def save(self, checkpoint_dir=None):
"""Saves the current model state to a checkpoint.
Subclasses should override ``_save()`` instead to save state.
This method dumps additional metadata alongside the saved path.
Args:
checkpoint_dir (str): Optional dir to place the checkpoint.
Returns:
Checkpoint path that may be passed to restore().
"""
checkpoint_path = self._save(checkpoint_dir or self.logdir)
pickle.dump([
self._experiment_id, self._iteration, self._timesteps_total,
self._time_total
], open(checkpoint_path + ".tune_metadata", "wb"))
return checkpoint_path
def save_to_object(self):
"""Saves the current model state to a Python object. It also
saves to disk but does not return the checkpoint path.
Returns:
Object holding checkpoint data.
"""
tmpdir = tempfile.mkdtemp("save_to_object", dir=self.logdir)
checkpoint_prefix = self.save(tmpdir)
data = {}
base_dir = os.path.dirname(checkpoint_prefix)
for path in os.listdir(base_dir):
path = os.path.join(base_dir, path)
if path.startswith(checkpoint_prefix):
data[os.path.basename(path)] = open(path, "rb").read()
out = io.BytesIO()
with gzip.GzipFile(fileobj=out, mode="wb") as f:
compressed = pickle.dumps({
"checkpoint_name": os.path.basename(checkpoint_prefix),
"data": data,
})
if len(compressed) > 10e6: # getting pretty large
print("Checkpoint size is {} bytes".format(len(compressed)))
f.write(compressed)
shutil.rmtree(tmpdir)
return out.getvalue()
def restore(self, checkpoint_path):
"""Restores training state from a given model checkpoint.
These checkpoints are returned from calls to save().
Subclasses should override ``_restore()`` instead to restore state.
This method restores additional metadata saved with the checkpoint.
"""
self._restore(checkpoint_path)
metadata = pickle.load(open(checkpoint_path + ".tune_metadata", "rb"))
self._experiment_id = metadata[0]
self._iteration = metadata[1]
self._timesteps_total = metadata[2]
self._time_total = metadata[3]
def restore_from_object(self, obj):
"""Restores training state from a checkpoint object.
These checkpoints are returned from calls to save_to_object().
"""
out = io.BytesIO(obj)
info = pickle.loads(gzip.GzipFile(fileobj=out, mode="rb").read())
data = info["data"]
tmpdir = tempfile.mkdtemp("restore_from_object", dir=self.logdir)
checkpoint_path = os.path.join(tmpdir, info["checkpoint_name"])
for file_name, file_contents in data.items():
with open(os.path.join(tmpdir, file_name), "wb") as f:
f.write(file_contents)
self.restore(checkpoint_path)
shutil.rmtree(tmpdir)
def stop(self):
"""Releases all resources used by this trainable."""
if self._initialize_ok:
self._result_logger.close()
self._stop()
def _train(self):
"""Subclasses should override this to implement train().
Returns:
A dict that describes training progress."""
raise NotImplementedError
def _save(self, checkpoint_dir):
"""Subclasses should override this to implement save()."""
raise NotImplementedError
def _restore(self, checkpoint_path):
"""Subclasses should override this to implement restore()."""
raise NotImplementedError
def _setup(self):
"""Subclasses should override this for custom initialization.
Subclasses can access the hyperparameter configuration via
``self.config``.
"""
pass
def _stop(self):
"""Subclasses should override this for any cleanup on stop."""
pass
def wrap_function(train_func):
from ray.tune.function_runner import FunctionRunner
class WrappedFunc(FunctionRunner):
def _trainable_func(self):
return train_func
return WrappedFunc