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ray/python/ray/rllib/test/test_optimizers.py
T
Eric Liang 6bb1103930 [rllib] Avoid sample wastage with bad PPO configurations (#3552)
## What do these changes do?

Previously we logged a warning if the PPO configuration would waste many samples. However, this didn't apply in the case of long episodes in `complete_episodes` batch mode, and also the amount of waste is up to 2x in common cases.

This pr:
- Estimates the number of sampling tasks needed to avoid over-sampling.
- Collects all sample results and never discards any. In principle this can degrade performance at large scale if certain machines are slower. Add a config flag to enable this legacy behavior.

## Related issue number

Closes: https://github.com/ray-project/ray/issues/3549
2018-12-20 10:50:44 -08:00

240 lines
8.1 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import gym
import numpy as np
import tensorflow as tf
import time
import unittest
import ray
from ray.rllib.agents.ppo import PPOAgent
from ray.rllib.agents.ppo.ppo_policy_graph import PPOPolicyGraph
from ray.rllib.evaluation import SampleBatch
from ray.rllib.evaluation.policy_evaluator import PolicyEvaluator
from ray.rllib.optimizers import AsyncGradientsOptimizer, AsyncSamplesOptimizer
from ray.rllib.test.mock_evaluator import _MockEvaluator
class AsyncOptimizerTest(unittest.TestCase):
def tearDown(self):
ray.shutdown()
def testBasic(self):
ray.init(num_cpus=4)
local = _MockEvaluator()
remotes = ray.remote(_MockEvaluator)
remote_evaluators = [remotes.remote() for i in range(5)]
test_optimizer = AsyncGradientsOptimizer(local, remote_evaluators,
{"grads_per_step": 10})
test_optimizer.step()
self.assertTrue(all(local.get_weights() == 0))
class PPOCollectTest(unittest.TestCase):
def tearDown(self):
ray.shutdown()
def testPPOSampleWaste(self):
ray.init(num_cpus=4)
# Check we at least collect the initial wave of samples
ppo = PPOAgent(
env="CartPole-v0",
config={
"sample_batch_size": 200,
"train_batch_size": 128,
"num_workers": 3,
})
ppo.train()
self.assertEqual(ppo.optimizer.num_steps_sampled, 600)
ppo.stop()
# Check we collect at least the specified amount of samples
ppo = PPOAgent(
env="CartPole-v0",
config={
"sample_batch_size": 200,
"train_batch_size": 900,
"num_workers": 3,
})
ppo.train()
self.assertEqual(ppo.optimizer.num_steps_sampled, 1000)
ppo.stop()
# Check in vectorized mode
ppo = PPOAgent(
env="CartPole-v0",
config={
"sample_batch_size": 200,
"num_envs_per_worker": 2,
"train_batch_size": 900,
"num_workers": 3,
})
ppo.train()
self.assertEqual(ppo.optimizer.num_steps_sampled, 1200)
ppo.stop()
# Check legacy mode
ppo = PPOAgent(
env="CartPole-v0",
config={
"sample_batch_size": 200,
"train_batch_size": 128,
"num_workers": 3,
"straggler_mitigation": True,
})
ppo.train()
self.assertEqual(ppo.optimizer.num_steps_sampled, 200)
ppo.stop()
class SampleBatchTest(unittest.TestCase):
def testConcat(self):
b1 = SampleBatch({"a": np.array([1, 2, 3]), "b": np.array([4, 5, 6])})
b2 = SampleBatch({"a": np.array([1]), "b": np.array([4])})
b3 = SampleBatch({"a": np.array([1]), "b": np.array([5])})
b12 = b1.concat(b2)
self.assertEqual(b12["a"].tolist(), [1, 2, 3, 1])
self.assertEqual(b12["b"].tolist(), [4, 5, 6, 4])
b = SampleBatch.concat_samples([b1, b2, b3])
self.assertEqual(b["a"].tolist(), [1, 2, 3, 1, 1])
self.assertEqual(b["b"].tolist(), [4, 5, 6, 4, 5])
class AsyncSamplesOptimizerTest(unittest.TestCase):
@classmethod
def tearDownClass(cls):
ray.shutdown()
@classmethod
def setUpClass(cls):
ray.init(num_cpus=8)
def testSimple(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(local, remotes, {})
self._wait_for(optimizer, 1000, 1000)
def testMultiGPU(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(local, remotes, {
"num_gpus": 2,
"_fake_gpus": True
})
self._wait_for(optimizer, 1000, 1000)
def testMultiGPUParallelLoad(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(local, remotes, {
"num_gpus": 2,
"num_data_loader_buffers": 2,
"_fake_gpus": True
})
self._wait_for(optimizer, 1000, 1000)
def testMultiplePasses(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"minibatch_buffer_size": 10,
"num_sgd_iter": 10,
"sample_batch_size": 10,
"train_batch_size": 50,
})
self._wait_for(optimizer, 1000, 10000)
self.assertLess(optimizer.stats()["num_steps_sampled"], 5000)
self.assertGreater(optimizer.stats()["num_steps_trained"], 8000)
def testReplay(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"replay_buffer_num_slots": 100,
"replay_proportion": 10,
"sample_batch_size": 10,
"train_batch_size": 10,
})
self._wait_for(optimizer, 1000, 1000)
self.assertLess(optimizer.stats()["num_steps_sampled"], 5000)
self.assertGreater(optimizer.stats()["num_steps_replayed"], 8000)
self.assertGreater(optimizer.stats()["num_steps_trained"], 8000)
def testReplayAndMultiplePasses(self):
local, remotes = self._make_evs()
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"minibatch_buffer_size": 10,
"num_sgd_iter": 10,
"replay_buffer_num_slots": 100,
"replay_proportion": 10,
"sample_batch_size": 10,
"train_batch_size": 10,
})
self._wait_for(optimizer, 1000, 1000)
self.assertLess(optimizer.stats()["num_steps_sampled"], 5000)
self.assertGreater(optimizer.stats()["num_steps_replayed"], 8000)
self.assertGreater(optimizer.stats()["num_steps_trained"], 40000)
def testRejectBadConfigs(self):
local, remotes = self._make_evs()
self.assertRaises(
ValueError, lambda: AsyncSamplesOptimizer(
local, remotes,
{"num_data_loader_buffers": 2, "minibatch_buffer_size": 4}))
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"num_gpus": 2,
"train_batch_size": 100,
"sample_batch_size": 50,
"_fake_gpus": True
})
self._wait_for(optimizer, 1000, 1000)
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"num_gpus": 2,
"train_batch_size": 100,
"sample_batch_size": 25,
"_fake_gpus": True
})
self._wait_for(optimizer, 1000, 1000)
optimizer = AsyncSamplesOptimizer(
local, remotes, {
"num_gpus": 2,
"train_batch_size": 100,
"sample_batch_size": 74,
"_fake_gpus": True
})
self._wait_for(optimizer, 1000, 1000)
def _make_evs(self):
def make_sess():
return tf.Session(config=tf.ConfigProto(device_count={"CPU": 2}))
local = PolicyEvaluator(
env_creator=lambda _: gym.make("CartPole-v0"),
policy_graph=PPOPolicyGraph,
tf_session_creator=make_sess)
remotes = [
PolicyEvaluator.as_remote().remote(
env_creator=lambda _: gym.make("CartPole-v0"),
policy_graph=PPOPolicyGraph,
tf_session_creator=make_sess)
]
return local, remotes
def _wait_for(self, optimizer, num_steps_sampled, num_steps_trained):
start = time.time()
while time.time() - start < 30:
optimizer.step()
if optimizer.num_steps_sampled > num_steps_sampled and \
optimizer.num_steps_trained > num_steps_trained:
print("OK", optimizer.stats())
return
raise AssertionError("TIMED OUT", optimizer.stats())
if __name__ == '__main__':
unittest.main(verbosity=2)