def execution_plan(
workers: WorkerSet, config: TrainerConfigDict, **kwargs
) -> LocalIterator[dict]:
"""Execution plan of the DD-PPO algorithm. Defines the distributed dataflow.
Args:
workers (WorkerSet): The WorkerSet for training the Polic(y/ies)
of the Trainer.
config (TrainerConfigDict): The trainer's configuration dict.
Returns:
LocalIterator[dict]: The Policy class to use with PGTrainer.
If None, use `get_default_policy_class()` provided by Trainer.
"""
assert (
len(kwargs) == 0
), "DDPPO execution_plan does NOT take any additional parameters"
rollouts = ParallelRollouts(workers, mode="raw")
# Setup the distributed processes.
ip = ray.get(workers.remote_workers()[0].get_node_ip.remote())
port = ray.get(workers.remote_workers()[0].find_free_port.remote())
address = "tcp://{ip}:{port}".format(ip=ip, port=port)
logger.info("Creating torch process group with leader {}".format(address))
# Get setup tasks in order to throw errors on failure.
ray.get(
[
worker.setup_torch_data_parallel.remote(
url=address,
world_rank=i,
world_size=len(workers.remote_workers()),
backend=config["torch_distributed_backend"],
)
for i, worker in enumerate(workers.remote_workers())
]
)
logger.info("Torch process group init completed")
# This function is applied remotely on each rollout worker.
def train_torch_distributed_allreduce(batch):
expected_batch_size = (
config["rollout_fragment_length"] * config["num_envs_per_worker"]
)
this_worker = get_global_worker()
assert batch.count == expected_batch_size, (
"Batch size possibly out of sync between workers, expected:",
expected_batch_size,
"got:",
batch.count,
)
logger.info(
"Executing distributed minibatch SGD "
"with epoch size {}, minibatch size {}".format(
batch.count, config["sgd_minibatch_size"]
)
)
info = do_minibatch_sgd(
batch,
this_worker.policy_map,
this_worker,
config["num_sgd_iter"],
config["sgd_minibatch_size"],
["advantages"],
)
return info, batch.count
# Broadcast the local set of global vars.
def update_worker_global_vars(item):
global_vars = _get_global_vars()
for w in workers.remote_workers():
w.set_global_vars.remote(global_vars)
return item
# Have to manually record stats since we are using "raw" rollouts mode.
class RecordStats:
def _on_fetch_start(self):
self.fetch_start_time = time.perf_counter()
def __call__(self, items):
assert len(items) == config["num_workers"]
for item in items:
info, count = item
metrics = _get_shared_metrics()
metrics.counters[STEPS_TRAINED_THIS_ITER_COUNTER] = count
metrics.counters[STEPS_SAMPLED_COUNTER] += count
metrics.counters[STEPS_TRAINED_COUNTER] += count
metrics.info[LEARNER_INFO] = info
# Since SGD happens remotely, the time delay between fetch and
# completion is approximately the SGD step time.
metrics.timers[LEARN_ON_BATCH_TIMER].push(
time.perf_counter() - self.fetch_start_time
)
train_op = (
rollouts.for_each(train_torch_distributed_allreduce) # allreduce
.batch_across_shards() # List[(grad_info, count)]
.for_each(RecordStats())
)
train_op = train_op.for_each(update_worker_global_vars)
# Sync down the weights. As with the sync up, this is not really
# needed unless the user is reading the local weights.
if config["keep_local_weights_in_sync"]:
def download_weights(item):
workers.local_worker().set_weights(
ray.get(workers.remote_workers()[0].get_weights.remote())
)
return item
train_op = train_op.for_each(download_weights)
# In debug mode, check the allreduce successfully synced the weights.
if logger.isEnabledFor(logging.DEBUG):
def check_sync(item):
weights = ray.get(
[w.get_weights.remote() for w in workers.remote_workers()]
)
sums = []
for w in weights:
acc = 0
for p in w.values():
for k, v in p.items():
acc += v.sum()
sums.append(float(acc))
logger.debug("The worker weight sums are {}".format(sums))
assert len(set(sums)) == 1, sums
train_op = train_op.for_each(check_sync)
return StandardMetricsReporting(train_op, workers, config)
def execution_plan(workers: WorkerSet,
config: TrainerConfigDict) -> LocalIterator[dict]:
"""Execution plan of the DQN algorithm. Defines the distributed dataflow.
Args:
workers (WorkerSet): The WorkerSet for training the Polic(y/ies)
of the Trainer.
config (TrainerConfigDict): The trainer's configuration dict.
Returns:
LocalIterator[dict]: A local iterator over training metrics.
"""
if config.get("prioritized_replay"):
prio_args = {
"prioritized_replay_alpha": config["prioritized_replay_alpha"],
"prioritized_replay_beta": config["prioritized_replay_beta"],
"prioritized_replay_eps": config["prioritized_replay_eps"],
}
else:
prio_args = {}
local_replay_buffer = LocalReplayBuffer(
num_shards=1,
learning_starts=config["learning_starts"],
buffer_size=config["buffer_size"],
replay_batch_size=config["train_batch_size"],
replay_mode=config["multiagent"]["replay_mode"],
replay_sequence_length=config.get("replay_sequence_length", 1),
replay_burn_in=config.get("burn_in", 0),
replay_zero_init_states=config.get("zero_init_states", True),
**prio_args)
rollouts = ParallelRollouts(workers, mode="bulk_sync")
# We execute the following steps concurrently:
# (1) Generate rollouts and store them in our local replay buffer. Calling
# next() on store_op drives this.
store_op = rollouts.for_each(
StoreToReplayBuffer(local_buffer=local_replay_buffer))
def update_prio(item):
samples, info_dict = item
if config.get("prioritized_replay"):
prio_dict = {}
for policy_id, info in info_dict.items():
# TODO(sven): This is currently structured differently for
# torch/tf. Clean up these results/info dicts across
# policies (note: fixing this in torch_policy.py will
# break e.g. DDPPO!).
td_error = info.get("td_error",
info[LEARNER_STATS_KEY].get("td_error"))
prio_dict[policy_id] = (samples.policy_batches[policy_id].data.
get("batch_indexes"), td_error)
local_replay_buffer.update_priorities(prio_dict)
return info_dict
# (2) Read and train on experiences from the replay buffer. Every batch
# returned from the LocalReplay() iterator is passed to TrainOneStep to
# take a SGD step, and then we decide whether to update the target network.
post_fn = config.get("before_learn_on_batch") or (lambda b, *a: b)
if config["simple_optimizer"]:
train_step_op = TrainOneStep(workers)
else:
train_step_op = TrainTFMultiGPU(
workers=workers,
sgd_minibatch_size=config["train_batch_size"],
num_sgd_iter=1,
num_gpus=config["num_gpus"],
shuffle_sequences=True,
_fake_gpus=config["_fake_gpus"],
framework=config.get("framework"))
replay_op = Replay(local_buffer=local_replay_buffer) \
.for_each(lambda x: post_fn(x, workers, config)) \
.for_each(train_step_op) \
.for_each(update_prio) \
.for_each(UpdateTargetNetwork(
workers, config["target_network_update_freq"]))
# Alternate deterministically between (1) and (2). Only return the output
# of (2) since training metrics are not available until (2) runs.
train_op = Concurrently([store_op, replay_op],
mode="round_robin",
output_indexes=[1],
round_robin_weights=calculate_rr_weights(config))
return StandardMetricsReporting(train_op, workers, config)
def execution_plan(workers: WorkerSet, config: dict,
**kwargs) -> LocalIterator[dict]:
assert (
len(kwargs) == 0
), "Apex execution_plan does NOT take any additional parameters"
# Create a number of replay buffer actors.
num_replay_buffer_shards = config["optimizer"][
"num_replay_buffer_shards"]
replay_actor_args = [
num_replay_buffer_shards,
config["learning_starts"],
config["buffer_size"],
config["train_batch_size"],
config["prioritized_replay_alpha"],
config["prioritized_replay_beta"],
config["prioritized_replay_eps"],
config["multiagent"]["replay_mode"],
config.get("replay_sequence_length", 1),
]
# Place all replay buffer shards on the same node as the learner
# (driver process that runs this execution plan).
if config["replay_buffer_shards_colocated_with_driver"]:
replay_actors = create_colocated_actors(
actor_specs=[
# (class, args, kwargs={}, count)
(ReplayActor, replay_actor_args, {},
num_replay_buffer_shards)
],
node=platform.node(), # localhost
)[0] # [0]=only one item in `actor_specs`.
# Place replay buffer shards on any node(s).
else:
replay_actors = [
ReplayActor(*replay_actor_args)
for _ in range(num_replay_buffer_shards)
]
# Start the learner thread.
learner_thread = LearnerThread(workers.local_worker())
learner_thread.start()
# Update experience priorities post learning.
def update_prio_and_stats(item: Tuple[ActorHandle, dict, int]) -> None:
actor, prio_dict, count = item
if config.get("prioritized_replay"):
actor.update_priorities.remote(prio_dict)
metrics = _get_shared_metrics()
# Manually update the steps trained counter since the learner
# thread is executing outside the pipeline.
metrics.counters[STEPS_TRAINED_THIS_ITER_COUNTER] = count
metrics.counters[STEPS_TRAINED_COUNTER] += count
metrics.timers["learner_dequeue"] = learner_thread.queue_timer
metrics.timers["learner_grad"] = learner_thread.grad_timer
metrics.timers["learner_overall"] = learner_thread.overall_timer
# We execute the following steps concurrently:
# (1) Generate rollouts and store them in one of our replay buffer
# actors. Update the weights of the worker that generated the batch.
rollouts = ParallelRollouts(workers, mode="async", num_async=2)
store_op = rollouts.for_each(StoreToReplayBuffer(actors=replay_actors))
# Only need to update workers if there are remote workers.
if workers.remote_workers():
store_op = store_op.zip_with_source_actor().for_each(
UpdateWorkerWeights(
learner_thread,
workers,
max_weight_sync_delay=(
config["optimizer"]["max_weight_sync_delay"]),
))
# (2) Read experiences from one of the replay buffer actors and send
# to the learner thread via its in-queue.
post_fn = config.get("before_learn_on_batch") or (lambda b, *a: b)
replay_op = (Replay(
actors=replay_actors, num_async=4).for_each(lambda x: post_fn(
x, workers, config)).zip_with_source_actor().for_each(
Enqueue(learner_thread.inqueue)))
# (3) Get priorities back from learner thread and apply them to the
# replay buffer actors.
update_op = (Dequeue(learner_thread.outqueue,
check=learner_thread.is_alive).for_each(
update_prio_and_stats).for_each(
UpdateTargetNetwork(
workers,
config["target_network_update_freq"],
by_steps_trained=True)))
if config["training_intensity"]:
# Execute (1), (2) with a fixed intensity ratio.
rr_weights = calculate_rr_weights(config) + ["*"]
merged_op = Concurrently(
[store_op, replay_op, update_op],
mode="round_robin",
output_indexes=[2],
round_robin_weights=rr_weights,
)
else:
# Execute (1), (2), (3) asynchronously as fast as possible. Only
# output items from (3) since metrics aren't available before
# then.
merged_op = Concurrently([store_op, replay_op, update_op],
mode="async",
output_indexes=[2])
# Add in extra replay and learner metrics to the training result.
def add_apex_metrics(result: dict) -> dict:
replay_stats = ray.get(replay_actors[0].stats.remote(
config["optimizer"].get("debug")))
exploration_infos = workers.foreach_policy_to_train(
lambda p, _: p.get_exploration_state())
result["info"].update({
"exploration_infos":
exploration_infos,
"learner_queue":
learner_thread.learner_queue_size.stats(),
LEARNER_INFO:
copy.deepcopy(learner_thread.learner_info),
"replay_shard_0":
replay_stats,
})
return result
# Only report metrics from the workers with the lowest 1/3 of
# epsilons.
selected_workers = workers.remote_workers(
)[-len(workers.remote_workers()) // 3:]
return StandardMetricsReporting(
merged_op, workers, config,
selected_workers=selected_workers).for_each(add_apex_metrics)
def execution_plan(workers, config):
if config.get("prioritized_replay"):
prio_args = {
"prioritized_replay_alpha": config["prioritized_replay_alpha"],
"prioritized_replay_beta": config["prioritized_replay_beta"],
"prioritized_replay_eps": config["prioritized_replay_eps"],
}
else:
prio_args = {}
local_replay_buffer = LocalReplayBuffer(
num_shards=1,
learning_starts=config["learning_starts"],
buffer_size=config["buffer_size"],
replay_batch_size=config["train_batch_size"],
replay_mode=config["multiagent"]["replay_mode"],
replay_sequence_length=config.get("replay_sequence_length", 1),
replay_burn_in=config.get("burn_in", 0),
replay_zero_init_states=config.get("zero_init_states", True),
**prio_args)
global replay_buffer
replay_buffer = local_replay_buffer
def update_prio(item):
samples, info_dict = item
if config.get("prioritized_replay"):
prio_dict = {}
for policy_id, info in info_dict.items():
# TODO(sven): This is currently structured differently for
# torch/tf. Clean up these results/info dicts across
# policies (note: fixing this in torch_policy.py will
# break e.g. DDPPO!).
td_error = info.get("td_error",
info[LEARNER_STATS_KEY].get("td_error"))
samples.policy_batches[policy_id].set_get_interceptor(None)
prio_dict[policy_id] = (samples.policy_batches[policy_id]
.get("batch_indexes"), td_error)
local_replay_buffer.update_priorities(prio_dict)
return info_dict
# (2) Read and train on experiences from the replay buffer. Every batch
# returned from the LocalReplay() iterator is passed to TrainOneStep to
# take a SGD step, and then we decide whether to update the target network.
post_fn = config.get("before_learn_on_batch") or (lambda b, *a: b)
if config["simple_optimizer"]:
train_step_op = TrainOneStep(workers)
else:
train_step_op = MultiGPUTrainOneStep(
workers=workers,
sgd_minibatch_size=config["train_batch_size"],
num_sgd_iter=1,
num_gpus=config["num_gpus"],
shuffle_sequences=True,
_fake_gpus=config["_fake_gpus"],
framework=config.get("framework"))
replay_op = Replay(local_buffer=local_replay_buffer) \
.for_each(lambda x: post_fn(x, workers, config)) \
.for_each(train_step_op) \
.for_each(update_prio) \
.for_each(UpdateTargetNetwork(
workers, config["target_network_update_freq"]))
return StandardMetricsReporting(
replay_op, workers, config, by_steps_trained=True)
def execution_plan(workers: WorkerSet, config: TrainerConfigDict,
**kwargs) -> LocalIterator[dict]:
"""Execution plan of the DQN algorithm. Defines the distributed dataflow.
Args:
trainer (Trainer): The Trainer object creating the execution plan.
workers (WorkerSet): The WorkerSet for training the Polic(y/ies)
of the Trainer.
config (TrainerConfigDict): The trainer's configuration dict.
Returns:
LocalIterator[dict]: A local iterator over training metrics.
"""
assert "local_replay_buffer" in kwargs, (
"GenericOffPolicyTrainer execution plan requires a "
"local replay buffer.")
# Assign to Trainer, so we can store the MultiAgentReplayBuffer's
# data when we save checkpoints.
local_replay_buffer = kwargs["local_replay_buffer"]
rollouts = ParallelRollouts(workers, mode="bulk_sync")
# We execute the following steps concurrently:
# (1) Generate rollouts and store them in our local replay buffer. Calling
# next() on store_op drives this.
store_op = rollouts.for_each(
StoreToReplayBuffer(local_buffer=local_replay_buffer))
def update_prio(item):
samples, info_dict = item
if config.get("prioritized_replay"):
prio_dict = {}
for policy_id, info in info_dict.items():
# TODO(sven): This is currently structured differently for
# torch/tf. Clean up these results/info dicts across
# policies (note: fixing this in torch_policy.py will
# break e.g. DDPPO!).
td_error = info.get("td_error",
info[LEARNER_STATS_KEY].get("td_error"))
samples.policy_batches[policy_id].set_get_interceptor(None)
batch_indices = samples.policy_batches[policy_id].get(
"batch_indexes")
# In case the buffer stores sequences, TD-error could already
# be calculated per sequence chunk.
if len(batch_indices) != len(td_error):
T = local_replay_buffer.replay_sequence_length
assert len(batch_indices) > len(
td_error) and len(batch_indices) % T == 0
batch_indices = batch_indices.reshape([-1, T])[:, 0]
assert len(batch_indices) == len(td_error)
prio_dict[policy_id] = (batch_indices, td_error)
local_replay_buffer.update_priorities(prio_dict)
return info_dict
# (2) Read and train on experiences from the replay buffer. Every batch
# returned from the LocalReplay() iterator is passed to TrainOneStep to
# take a SGD step, and then we decide whether to update the target network.
post_fn = config.get("before_learn_on_batch") or (lambda b, *a: b)
if config["simple_optimizer"]:
train_step_op = TrainOneStep(workers)
else:
train_step_op = MultiGPUTrainOneStep(
workers=workers,
sgd_minibatch_size=config["train_batch_size"],
num_sgd_iter=1,
num_gpus=config["num_gpus"],
shuffle_sequences=True,
_fake_gpus=config["_fake_gpus"],
framework=config.get("framework"))
replay_op = Replay(local_buffer=local_replay_buffer) \
.for_each(lambda x: post_fn(x, workers, config)) \
.for_each(train_step_op) \
.for_each(update_prio) \
.for_each(UpdateTargetNetwork(
workers, config["target_network_update_freq"]))
# Alternate deterministically between (1) and (2). Only return the output
# of (2) since training metrics are not available until (2) runs.
train_op = Concurrently([store_op, replay_op],
mode="round_robin",
output_indexes=[1],
round_robin_weights=calculate_rr_weights(config))
return StandardMetricsReporting(train_op, workers, config)
def execution_plan(workers, config):
# Create a number of replay buffer actors.
# TODO(ekl) support batch replay options
num_replay_buffer_shards = config["optimizer"]["num_replay_buffer_shards"]
replay_actors = create_colocated(ReplayActor, [
num_replay_buffer_shards,
config["learning_starts"],
config["buffer_size"],
config["train_batch_size"],
config["prioritized_replay_alpha"],
config["prioritized_replay_beta"],
config["prioritized_replay_eps"],
], num_replay_buffer_shards)
# Update experience priorities post learning.
def update_prio_and_stats(item):
actor, prio_dict, count = item
actor.update_priorities.remote(prio_dict)
metrics = LocalIterator.get_metrics()
# Manually update the steps trained counter since the learner thread
# is executing outside the pipeline.
metrics.counters[STEPS_TRAINED_COUNTER] += count
metrics.timers["learner_dequeue"] = learner_thread.queue_timer
metrics.timers["learner_grad"] = learner_thread.grad_timer
metrics.timers["learner_overall"] = learner_thread.overall_timer
# Update worker weights as they finish generating experiences.
class UpdateWorkerWeights:
def __init__(self, learner_thread, workers, max_weight_sync_delay):
self.learner_thread = learner_thread
self.workers = workers
self.steps_since_update = collections.defaultdict(int)
self.max_weight_sync_delay = max_weight_sync_delay
self.weights = None
def __call__(self, item):
actor, batch = item
self.steps_since_update[actor] += batch.count
if self.steps_since_update[actor] >= self.max_weight_sync_delay:
# Note that it's important to pull new weights once
# updated to avoid excessive correlation between actors.
if self.weights is None or self.learner_thread.weights_updated:
self.learner_thread.weights_updated = False
self.weights = ray.put(
self.workers.local_worker().get_weights())
actor.set_weights.remote(self.weights)
self.steps_since_update[actor] = 0
# Update metrics.
metrics = LocalIterator.get_metrics()
metrics.counters["num_weight_syncs"] += 1
# Start the learner thread.
learner_thread = LearnerThread(workers.local_worker())
learner_thread.start()
# We execute the following steps concurrently:
# (1) Generate rollouts and store them in our replay buffer actors. Update
# the weights of the worker that generated the batch.
rollouts = ParallelRollouts(workers, mode="async", async_queue_depth=2)
store_op = rollouts \
.for_each(StoreToReplayActors(replay_actors)) \
.zip_with_source_actor() \
.for_each(UpdateWorkerWeights(
learner_thread, workers,
max_weight_sync_delay=config["optimizer"]["max_weight_sync_delay"])
)
# (2) Read experiences from the replay buffer actors and send to the
# learner thread via its in-queue.
replay_op = ParallelReplay(replay_actors, async_queue_depth=4) \
.zip_with_source_actor() \
.for_each(Enqueue(learner_thread.inqueue))
# (3) Get priorities back from learner thread and apply them to the
# replay buffer actors.
update_op = Dequeue(
learner_thread.outqueue, check=learner_thread.is_alive) \
.for_each(update_prio_and_stats) \
.for_each(UpdateTargetNetwork(
workers, config["target_network_update_freq"],
by_steps_trained=True))
# Execute (1), (2), (3) asynchronously as fast as possible.
merged_op = Concurrently([store_op, replay_op, update_op], mode="async")
return StandardMetricsReporting(merged_op, workers, config)
