ray/rllib/algorithms/tests/test_worker_failures.py

732 lines
26 KiB
Python

from collections import defaultdict
import gym
import numpy as np
import time
import unittest
import ray
from ray.rllib.algorithms.pg import PG, PGConfig
from ray.rllib.algorithms.registry import get_algorithm_class
from ray.rllib.env.multi_agent_env import make_multi_agent
from ray.rllib.examples.env.random_env import RandomEnv
from ray.rllib.policy.policy import PolicySpec
from ray.rllib.utils.test_utils import framework_iterator
from ray.tune.registry import register_env
@ray.remote
class Counter:
"""Remote counter service that survives restarts."""
def __init__(self):
self.reset()
def _key(self, eval, worker_index, vector_index):
return f"{eval}:{worker_index}:{vector_index}"
def increment(self, eval, worker_index, vector_index):
self.counter[self._key(eval, worker_index, vector_index)] += 1
def get(self, eval, worker_index, vector_index):
return self.counter[self._key(eval, worker_index, vector_index)]
def reset(self):
self.counter = defaultdict(int)
class FaultInjectEnv(gym.Env):
"""Env that fails upon calling `step()`, but only for some remote worker indices.
The worker indices that should produce the failure (a ValueError) can be
provided by a list (of ints) under the "bad_indices" key in the env's
config.
Examples:
>>> from ray.rllib.env.env_context import EnvContext
>>> # This env will fail for workers 1 and 2 (not for the local worker
>>> # or any others with an index != [1|2]).
>>> bad_env = FaultInjectEnv(
... EnvContext(
... {"bad_indices": [1, 2]},
... worker_index=1,
... num_workers=3,
.. )
... )
>>> from ray.rllib.env.env_context import EnvContext
>>> # This env will fail only on the first evaluation worker, not on the first
>>> # regular rollout worker.
>>> bad_env = FaultInjectEnv(
... EnvContext(
... {"bad_indices": [1], "eval_only": True},
... worker_index=2,
... num_workers=5,
... )
... )
"""
def __init__(self, config):
# Use RandomEnv to control episode length if needed.
self.env = RandomEnv(config)
self._skip_env_checking = True
self.action_space = self.env.action_space
self.observation_space = self.env.observation_space
self.config = config
# External counter service.
if "counter" in config:
self.counter = ray.get_actor(config["counter"])
else:
self.counter = None
if config.get("init_delay", 0) > 0.0:
# Simulate an initialization delay.
time.sleep(config.get("init_delay"))
def _increment_count(self):
if self.counter:
eval = self.config.get("evaluation", False)
worker_index = self.config.worker_index
vector_index = self.config.vector_index
ray.wait([self.counter.increment.remote(eval, worker_index, vector_index)])
def _get_count(self):
if self.counter:
eval = self.config.get("evaluation", False)
worker_index = self.config.worker_index
vector_index = self.config.vector_index
return ray.get(self.counter.get.remote(eval, worker_index, vector_index))
return -1
def _maybe_raise_error(self):
# Do not raise simulated error if this worker is not bad.
if self.config.worker_index not in self.config.get("bad_indices", []):
return
# Do not raise simulated error if recreated worker can not fail,
# and this is a recreated worker.
if (
not self.config.get("recreated_worker_can_fail", False)
and self.config.recreated_worker
):
return
if self.counter:
count = self._get_count()
if self.config.get(
"failure_start_count", -1
) >= 0 and count < self.config.get("failure_start_count"):
return
if self.config.get(
"failure_stop_count", -1
) >= 0 and count >= self.config.get("failure_stop_count"):
return
raise ValueError(
"This is a simulated error from "
f"{'eval-' if self.config.get('evaluation', False) else ''}"
f"worker-idx={self.config.worker_index}!"
)
def reset(self):
self._increment_count()
self._maybe_raise_error()
return self.env.reset()
def step(self, action):
self._increment_count()
self._maybe_raise_error()
return self.env.step(action)
def is_recreated(w):
return w.apply.remote(
lambda w: w.recreated_worker or w.env_context.recreated_worker
)
class TestWorkerFailure(unittest.TestCase):
@classmethod
def setUpClass(cls) -> None:
ray.init()
register_env("fault_env", lambda c: FaultInjectEnv(c))
register_env(
"multi-agent-fault_env", lambda c: make_multi_agent(FaultInjectEnv)(c)
)
@classmethod
def tearDownClass(cls) -> None:
ray.shutdown()
def _do_test_fault_ignore(self, algo: str, config: dict, fail_eval: bool = False):
algo_cls = get_algorithm_class(algo)
# Test fault handling
config["num_workers"] = 2
config["ignore_worker_failures"] = True
# Make worker idx=1 fail. Other workers will be ok.
config["env_config"] = {"bad_indices": [1]}
if fail_eval:
config["evaluation_num_workers"] = 2
config["evaluation_interval"] = 1
config["evaluation_config"] = {
"ignore_worker_failures": True,
"env_config": {
# Make worker idx=1 fail. Other workers will be ok.
"bad_indices": [1],
"evaluation": True,
},
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
algo = algo_cls(config=config, env="fault_env")
result = algo.train()
# Both rollout workers are healthy.
self.assertTrue(result["num_healthy_workers"] == 1)
if fail_eval:
# One of the eval workers failed.
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 1)
algo.stop()
def _do_test_fault_fatal(self, alg, config, fail_eval=False):
agent_cls = get_algorithm_class(alg)
# Test raises real error when out of workers.
config["num_workers"] = 2
config["ignore_worker_failures"] = False
# Make both worker idx=1 and 2 fail.
config["env_config"] = {"bad_indices": [1, 2]}
if fail_eval:
config["evaluation_num_workers"] = 2
config["evaluation_interval"] = 1
config["evaluation_config"] = {
"ignore_worker_failures": False,
# Make eval worker (index 1) fail.
"env_config": {
"bad_indices": [1],
"evaluation": True,
},
}
for _ in framework_iterator(config, frameworks=("torch", "tf")):
a = agent_cls(config=config, env="fault_env")
self.assertRaises(Exception, lambda: a.train())
a.stop()
def test_fatal(self):
# Test the case where all workers fail (w/o recovery).
self._do_test_fault_fatal("PG", {"optimizer": {}})
def test_async_grads(self):
self._do_test_fault_ignore("A3C", {"optimizer": {"grads_per_step": 1}})
def test_async_replay(self):
self._do_test_fault_ignore(
"APEX",
{
"num_gpus": 0,
"min_sample_timesteps_per_iteration": 1000,
"min_time_s_per_iteration": 1,
"explore": False,
"learning_starts": 1000,
"target_network_update_freq": 100,
"optimizer": {
"num_replay_buffer_shards": 1,
},
},
)
def test_async_samples(self):
self._do_test_fault_ignore("IMPALA", {"num_gpus": 0})
def test_sync_replay(self):
self._do_test_fault_ignore("DQN", {"min_sample_timesteps_per_iteration": 1})
def test_multi_g_p_u(self):
self._do_test_fault_ignore(
"PPO",
{
"num_sgd_iter": 1,
"train_batch_size": 10,
"rollout_fragment_length": 10,
"sgd_minibatch_size": 1,
},
)
def test_sync_samples(self):
self._do_test_fault_ignore("PG", {"optimizer": {}})
def test_async_sampling_option(self):
self._do_test_fault_ignore("PG", {"optimizer": {}, "sample_async": True})
def test_eval_workers_failing_ignore(self):
# Test the case where one eval worker fails, but we chose to ignore.
self._do_test_fault_ignore(
"PG",
config={"model": {"fcnet_hiddens": [4]}},
fail_eval=True,
)
def test_eval_workers_failing_fatal(self):
# Test the case where all eval workers fail (w/o recovery).
self._do_test_fault_fatal(
"PG",
config={"model": {"fcnet_hiddens": [4]}},
fail_eval=True,
)
def test_workers_fatal_but_recover(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_workers_fatal_but_recover"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 2,
# Worker fault tolerance.
"ignore_worker_failures": False, # Do not ignore
"recreate_failed_workers": True, # But recover.
"model": {"fcnet_hiddens": [4]},
"env_config": {
# Make both worker idx=1 and 2 fail.
"bad_indices": [1, 2],
# Env throws error between steps 100 and 102.
"failure_start_count": 100,
"failure_stop_count": 102,
"counter": COUNTER_NAME,
},
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="fault_env")
# Before train loop, workers are fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
result = a.train()
self.assertEqual(result["num_healthy_workers"], 2)
# Workers are re-created.
self.assertEqual(result["num_recreated_workers"], 2)
self.assertTrue(
all(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
def test_eval_workers_fault_but_recover(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_eval_workers_fault_but_recover"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 2,
# Worker fault tolerance.
"ignore_worker_failures": True, # Ignore failure.
"recreate_failed_workers": True, # And recover.
"model": {"fcnet_hiddens": [4]},
# 2 eval workers.
"evaluation_num_workers": 2,
"evaluation_interval": 1,
"evaluation_config": {
"env_config": {
"evaluation": True,
"p_done": 0.0,
"max_episode_len": 20,
# Make both eval workers fail.
"bad_indices": [1, 2],
# Env throws error between steps 10 and 12.
"failure_start_count": 10,
"failure_stop_count": 12,
"counter": COUNTER_NAME,
}
},
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="fault_env")
# Before train loop, workers are fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
# Eval workers are also fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[
is_recreated(worker)
for worker in a.evaluation_workers.remote_workers()
]
)
)
)
result = a.train()
self.assertEqual(result["num_healthy_workers"], 2)
# Nothing happens to worker. They are still not re-created.
self.assertEqual(result["num_recreated_workers"], 0)
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
self.assertEqual(result["evaluation"]["num_healthy_workers"], 2)
# But all the eval workers are re-created.
self.assertEqual(result["evaluation"]["num_recreated_workers"], 2)
self.assertTrue(
all(
ray.get(
[
is_recreated(worker)
for worker in a.evaluation_workers.remote_workers()
]
)
)
)
def test_eval_workers_fault_but_restore_env(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_eval_workers_fault_but_restore_env"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 2,
# Worker fault tolerance.
"ignore_worker_failures": True,
"recreate_failed_workers": True,
"model": {"fcnet_hiddens": [4]},
"env_config": {
# Make both worker idx=1 and 2 fail.
"bad_indices": [1, 2],
# Env throws error before step 2.
"failure_stop_count": 2,
"counter": COUNTER_NAME,
},
# 2 eval workers.
"evaluation_num_workers": 2,
"evaluation_interval": 1,
"evaluation_config": {
"ignore_worker_failures": True,
"recreate_failed_workers": True,
# Now instead of recreating failed workers,
# we want to recreate the failed sub env instead.
"restart_failed_sub_environments": True,
"env_config": {
"evaluation": True,
# Make eval worker (index 1) fail.
"bad_indices": [1],
},
},
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="fault_env")
# Before train loop, workers are fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
result = a.train()
self.assertTrue(result["num_healthy_workers"] == 2)
# Workers are re-created.
self.assertEqual(result["num_recreated_workers"], 2)
self.assertTrue(
all(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 2)
# However eval worker is not, since we want to restart
# individual env.
self.assertEqual(result["evaluation"]["num_recreated_workers"], 0)
self.assertTrue(
not any(
ray.get(
[
is_recreated(worker)
for worker in a.evaluation_workers.remote_workers()
]
)
)
)
# This should also work several times.
result = a.train()
self.assertTrue(result["num_healthy_workers"] == 2)
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 2)
a.stop()
def test_multi_agent_env_eval_workers_fault_but_restore_env(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_multi_agent_env_eval_workers_fault_but_restore_env"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 2,
"model": {"fcnet_hiddens": [4]},
# Workers do not fault and no fault tolerance.
"env_config": {},
"multiagent": {
"policies": {
"main_agent": PolicySpec(),
},
"policies_to_train": ["main_agent"],
"policy_mapping_fn": lambda _: "main_agent",
},
# 2 eval workers.
"evaluation_num_workers": 2,
"evaluation_interval": 1,
"evaluation_config": {
# Now instead of recreating failed workers,
# we want to recreate the failed sub env instead.
"restart_failed_sub_environments": True,
"env_config": {
"evaluation": True,
"p_done": 0.0,
"max_episode_len": 20,
# Make eval worker (index 1) fail.
"bad_indices": [1],
"counter": COUNTER_NAME,
"failure_start_count": 10,
"failure_stop_count": 12,
},
},
"disable_env_checking": True,
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="multi-agent-fault_env")
result = a.train()
self.assertTrue(result["num_healthy_workers"] == 2)
self.assertEqual(result["num_faulty_episodes"], 0)
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 2)
self.assertEqual(result["evaluation"]["num_recreated_workers"], 0)
# There should be a faulty episode.
self.assertEqual(result["evaluation"]["num_faulty_episodes"], 2)
# This should also work several times.
result = a.train()
self.assertTrue(result["num_healthy_workers"] == 2)
self.assertEqual(result["num_faulty_episodes"], 0)
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 2)
self.assertEqual(result["evaluation"]["num_recreated_workers"], 0)
# There shouldn't be any faulty episode anymore.
self.assertEqual(result["evaluation"]["num_faulty_episodes"], 0)
a.stop()
def test_long_failure_period_restore_env(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_long_failure_period_restore_env"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 1,
"create_env_on_driver": False,
# Worker fault tolerance.
"recreate_failed_workers": True, # Restore failed workers.
"restart_failed_sub_environments": True, # And create failed envs.
"model": {"fcnet_hiddens": [4]},
"env_config": {
"p_done": 0.0,
"max_episode_len": 100,
"bad_indices": [1],
# Env throws error between steps 50 and 150.
"failure_start_count": 30,
"failure_stop_count": 80,
"counter": COUNTER_NAME,
},
# 2 eval workers.
"evaluation_num_workers": 1,
"evaluation_interval": 1,
"evaluation_config": {
"env_config": {
"evaluation": True,
}
},
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="fault_env")
# Before train loop, workers are fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
# Eval workers are also fresh and not recreated.
self.assertTrue(
not any(
ray.get(
[
is_recreated(worker)
for worker in a.evaluation_workers.remote_workers()
]
)
)
)
result = a.train()
# Should see a lot of faulty episodes.
self.assertGreaterEqual(result["num_faulty_episodes"], 50)
self.assertGreaterEqual(result["evaluation"]["num_faulty_episodes"], 50)
self.assertTrue(result["num_healthy_workers"] == 1)
# All workers are still not restored, since env are restored.
self.assertTrue(
not any(
ray.get(
[is_recreated(worker) for worker in a.workers.remote_workers()]
)
)
)
self.assertTrue(result["evaluation"]["num_healthy_workers"] == 1)
# All eval workers are still not restored, since env are recreated.
self.assertTrue(
not any(
ray.get(
[
is_recreated(worker)
for worker in a.evaluation_workers.remote_workers()
]
)
)
)
def test_env_wait_time_workers_restore_env(self):
# Counter that will survive restarts.
COUNTER_NAME = "test_env_wait_time_workers_restore_env"
counter = Counter.options(name=COUNTER_NAME).remote()
config = {
"num_workers": 1,
# Worker fault tolerance.
"ignore_worker_failures": False, # Do not ignore
"recreate_failed_workers": True, # But recover.
"restart_failed_sub_environments": True,
"model": {"fcnet_hiddens": [4]},
"rollout_fragment_length": 10,
"train_batch_size": 10,
"env_config": {
"p_done": 0.0,
"max_episode_len": 10,
"init_delay": 10, # 10 sec init delay.
# Make both worker idx=1 and 2 fail.
"bad_indices": [1],
# Env throws error between steps 100 and 102.
"failure_start_count": 7,
"failure_stop_count": 8,
"counter": COUNTER_NAME,
},
# Use EMA PerfStat.
# Really large coeff to show the difference in env_wait_time_ms.
# Pretty much consider the last 2 data points.
"sampler_perf_stats_ema_coef": 0.5,
# Important, don't smooth over all the episodes,
# otherwise we don't see latency spike.
"metrics_num_episodes_for_smoothing": 1,
}
for _ in framework_iterator(config, frameworks=("tf2", "torch")):
# Reset interaciton counter.
ray.wait([counter.reset.remote()])
a = PG(config=config, env="fault_env")
# Had to restore env during this iteration.
result = a.train()
self.assertEqual(result["num_faulty_episodes"], 1)
time_with_restore = result["sampler_perf"]["mean_env_wait_ms"]
# Doesn't have to restore env during this iteration.
result = a.train()
# Still only 1 faulty episode.
self.assertEqual(result["num_faulty_episodes"], 0)
time_without_restore = result["sampler_perf"]["mean_env_wait_ms"]
# wait time with restore is at least 2 times wait time without restore.
self.assertGreater(time_with_restore, 2 * time_without_restore)
def test_eval_workers_on_infinite_episodes(self):
"""Tests whether eval workers warn appropriately after some episode timeout."""
# Create infinitely running episodes, but with horizon setting (RLlib will
# auto-terminate the episode). However, in the eval workers, don't set a
# horizon -> Expect warning and no proper evaluation results.
config = (
PGConfig()
.rollouts(num_rollout_workers=2, horizon=100)
.reporting(metrics_episode_collection_timeout_s=5.0)
.environment(env=RandomEnv, env_config={"p_done": 0.0})
.evaluation(
evaluation_num_workers=2,
evaluation_interval=1,
evaluation_sample_timeout_s=5.0,
evaluation_config={
"horizon": None,
},
)
)
algo = config.build()
results = algo.train()
self.assertTrue(np.isnan(results["evaluation"]["episode_reward_mean"]))
if __name__ == "__main__":
import sys
import pytest
sys.exit(pytest.main(["-v", __file__]))