[RLlib; Offline RL] - Enable reading old-stack SampleBatch data in new stack Offline RL.

rllib/BUILD

@@ -1867,6 +1867,7 @@ py_test(
     srcs = ["offline/tests/test_offline_data.py"],
     data = [
         "tests/data/cartpole/cartpole-v1_large",
+        "tests/data/cartpole/large.json",
     ],
 )
 

rllib/algorithms/algorithm_config.py

@@ -437,6 +437,7 @@ def __init__(self, algo_class: Optional[type] = None):
         self.input_read_method_kwargs = {}
         self.input_read_schema = {}
         self.input_read_episodes = False
+        self.input_read_sample_batches = False
         self.input_compress_columns = [Columns.OBS, Columns.NEXT_OBS]
         self.input_spaces_jsonable = True
         self.map_batches_kwargs = {}
@@ -2403,6 +2404,7 @@ def offline_data(
         input_read_method_kwargs: Optional[Dict] = NotProvided,
         input_read_schema: Optional[Dict[str, str]] = NotProvided,
         input_read_episodes: Optional[bool] = NotProvided,
+        input_read_sample_batches: Optional[bool] = NotProvided,
         input_compress_columns: Optional[List[str]] = NotProvided,
         map_batches_kwargs: Optional[Dict] = NotProvided,
         iter_batches_kwargs: Optional[Dict] = NotProvided,
@@ -2464,8 +2466,19 @@ def offline_data(
                 inside of RLlib's schema. The other format is a columnar format and is
                 agnostic to the RL framework used. Use the latter format, if you are
                 unsure when to use the data or in which RL framework. The default is
-                to read column data, i.e. `False`. See also `output_write_episodes`
-                to define the output data format when recording.
+                to read column data, i.e. `False`. `input_read_episodes` and
+                `inpuit_read_sample_batches` cannot be `True` at the same time. See
+                also `output_write_episodes` to define the output data format when
+                recording.
+            input_read_sample_batches: Whether offline data is stored in RLlib's old
+                stack `SampleBatch` type. This is usually the case for older data
+                recorded with RLlib in JSON line format. Reading in `SampleBatch`
+                data needs extra transforms and might not concatenate episode chunks
+                contained in different `SampleBatch`es in the data. If possible avoid
+                to read `SampleBatch`es and convert them in a controlled form into
+                RLlib`s `EpisodeType`s (i.e. `SingleAgentEpisode` or
+                `MultiAgentEpisode`). The default is `False`. `input_read_episodes`
+                and `inpuit_read_sample_batches` cannot be `True` at the same time.
             input_compress_columns: What input columns are compressed with LZ4 in the
                 input data. If data is stored in `RLlib`'s `SingleAgentEpisode` (
                 `MultiAgentEpisode` not supported, yet). Note,
@@ -2565,6 +2578,8 @@ def offline_data(
             self.input_read_schema = input_read_schema
         if input_read_episodes is not NotProvided:
             self.input_read_episodes = input_read_episodes
+        if input_read_sample_batches is not NotProvided:
+            self.input_read_sample_batches = input_read_sample_batches
         if input_compress_columns is not NotProvided:
             self.input_compress_columns = input_compress_columns
         if map_batches_kwargs is not NotProvided:

rllib/algorithms/marwil/marwil_offline_prelearner.py

@@ -26,6 +26,15 @@ def __call__(self, batch: Dict[str, np.ndarray]) -> Dict[str, MultiAgentBatch]:
         # If we directly read in episodes we just convert to list.
         if self.input_read_episodes:
             episodes = batch["item"].tolist()
+        # Else, if we have old stack `SampleBatch`es.
+        elif self.input_read_sample_batches:
+            episodes = OfflinePreLearner._map_sample_batch_to_episode(
+                self._is_multi_agent,
+                batch,
+                finalize=False,
+                schema=SCHEMA | self.config.input_read_schema,
+                input_compress_columns=self.config.input_compress_columns,
+            )["episodes"]
         # Otherwise we ap the batch to episodes.
         else:
             # Map the batch to episodes.

rllib/offline/offline_data.py

@@ -4,6 +4,7 @@
 
 from ray.rllib.algorithms.algorithm_config import AlgorithmConfig
 from ray.rllib.core import COMPONENT_RL_MODULE
+from ray.rllib.env import INPUT_ENV_SPACES
 from ray.rllib.offline.offline_prelearner import OfflinePreLearner
 from ray.rllib.utils.annotations import (
     ExperimentalAPI,
@@ -24,7 +25,7 @@ def __init__(self, config: AlgorithmConfig):
         self.path = (
             config.input_ if isinstance(config.input_, list) else Path(config.input_)
         )
-        # Use `read_json` as default data read method.
+        # Use `read_parquet` as default data read method.
         self.data_read_method = config.input_read_method
         # Override default arguments for the data read method.
         self.data_read_method_kwargs = (
@@ -72,12 +73,13 @@ def sample(
             # TODO (simon, sven): The iterator depends on the `num_samples`, i.e.abs
             # sampling later with a different batch size would need a
             # reinstantiation of the iterator.
+
             self.batch_iterator = self.data.map_batches(
                 self.prelearner_class,
                 fn_constructor_kwargs={
                     "config": self.config,
                     "learner": self.learner_handles[0],
-                    "spaces": self.spaces["__env__"],
+                    "spaces": self.spaces[INPUT_ENV_SPACES],
                 },
                 batch_size=num_samples,
                 **self.map_batches_kwargs,

rllib/offline/offline_prelearner.py

@@ -90,6 +90,7 @@ def __init__(
 
         self.config = config
         self.input_read_episodes = self.config.input_read_episodes
+        self.input_read_sample_batches = self.config.input_read_sample_batches
         # We need this learner to run the learner connector pipeline.
         # If it is a `Learner` instance, the `Learner` is local.
         if isinstance(learner, Learner):
@@ -144,7 +145,16 @@ def __call__(self, batch: Dict[str, np.ndarray]) -> Dict[str, List[EpisodeType]]
         # If we directly read in episodes we just convert to list.
         if self.input_read_episodes:
             episodes = batch["item"].tolist()
-        # Otherwise we ap the batch to episodes.
+        # Else, if we have old stack `SampleBatch`es.
+        elif self.input_read_sample_batches:
+            episodes = OfflinePreLearner._map_sample_batch_to_episode(
+                self._is_multi_agent,
+                batch,
+                finalize=False,
+                schema=SCHEMA | self.config.input_read_schema,
+                input_compress_columns=self.config.input_compress_columns,
+            )["episodes"]
+        # Otherwise we map the batch to episodes.
         else:
             episodes = self._map_to_episodes(
                 self._is_multi_agent,
@@ -227,7 +237,7 @@ def _should_module_be_updated(self, module_id, multi_agent_batch=None):
     @staticmethod
     def _map_to_episodes(
         is_multi_agent: bool,
-        batch: Dict[str, np.ndarray],
+        batch: Dict[str, Union[list, np.ndarray]],
         schema: Dict[str, str] = SCHEMA,
         finalize: bool = False,
         input_compress_columns: Optional[List[str]] = None,
@@ -271,7 +281,7 @@ def convert(sample, space):
 
             if is_multi_agent:
                 # TODO (simon): Add support for multi-agent episodes.
-                pass
+                NotImplementedError
             else:
                 # Build a single-agent episode with a single row of the batch.
                 episode = SingleAgentEpisode(
@@ -288,7 +298,7 @@ def convert(sample, space):
                             unpack_if_needed(batch[schema[Columns.NEXT_OBS]][i]),
                             observation_space,
                         )
-                        if Columns.NEXT_OBS in input_compress_columns
+                        if Columns.OBS in input_compress_columns
                         else convert(
                             batch[schema[Columns.NEXT_OBS]][i], observation_space
                         ),
@@ -334,7 +344,11 @@ def convert(sample, space):
                             else v[i]
                         ]
                         for k, v in batch.items()
-                        if (k not in schema and k not in schema.values())
+                        if (
+                            k not in schema
+                            and k not in schema.values()
+                            and k not in ["dones", "agent_index", "type"]
+                        )
                     },
                     len_lookback_buffer=0,
                 )
@@ -344,3 +358,111 @@ def convert(sample, space):
             episodes.append(episode)
         # Note, `map_batches` expects a `Dict` as return value.
         return {"episodes": episodes}
+
+    def _map_sample_batch_to_episode(
+        is_multi_agent: bool,
+        batch: Dict[str, Union[list, np.ndarray]],
+        schema: Dict[str, str] = SCHEMA,
+        finalize: bool = False,
+        input_compress_columns: Optional[List[str]] = None,
+    ) -> Dict[str, List[EpisodeType]]:
+        """Maps an old stack `SampleBatch` to new stack episodes."""
+
+        # Set `input_compress_columns` to an empty `list` if `None`.
+        input_compress_columns = input_compress_columns or []
+
+        # TODO (simon): CHeck, if needed. It could possibly happen that a batch contains
+        #   data from different episodes. Merging and resplitting the batch would then
+        # be the solution.
+        # Check, if batch comes actually from multiple episodes.
+        # episode_begin_indices = np.where(np.diff(np.hstack(batch["eps_id"])) != 0) + 1
+
+        # Define a container to collect episodes.
+        episodes = []
+        # Loop over `SampleBatch`es in the `ray.data` batch (a dict).
+        for i, obs in enumerate(batch[schema[Columns.OBS]]):
+
+            # If multi-agent we need to extract the agent ID.
+            # TODO (simon): Check, what happens with the module ID.
+            if is_multi_agent:
+                agent_id = (
+                    # The old stack uses "agent_index" instead of "agent_id".
+                    batch[schema["agent_index"]][i][0]
+                    if schema["agent_index"] in batch
+                    else None
+                )
+            else:
+                agent_id = None
+
+            if is_multi_agent:
+                # TODO (simon): Add support for multi-agent episodes.
+                NotImplementedError
+            else:
+                # Unpack observations, if needed.
+                obs = (
+                    unpack_if_needed(obs.tolist())
+                    if schema[Columns.OBS] in input_compress_columns
+                    else obs.tolist()
+                )
+                # Append the last `new_obs` to get the correct length of observations.
+                obs.append(
+                    unpack_if_needed(batch[schema[Columns.NEXT_OBS]][i][-1])
+                    if schema[Columns.OBS] in input_compress_columns
+                    else batch[schema[Columns.NEXT_OBS]][i][-1]
+                )
+                # Create a `SingleAgentEpisode`.
+                episode = SingleAgentEpisode(
+                    id_=batch[schema[Columns.EPS_ID]][i][0],
+                    agent_id=agent_id,
+                    observations=obs,
+                    infos=(
+                        batch[schema[Columns.INFOS]][i]
+                        if schema[Columns.INFOS] in batch
+                        else [{}] * len(obs)
+                    ),
+                    # Actions might be (a) serialized. We unserialize them here.
+                    actions=(
+                        unpack_if_needed(batch[schema[Columns.ACTIONS]][i])
+                        if Columns.ACTIONS in input_compress_columns
+                        else batch[schema[Columns.ACTIONS]][i]
+                    ),
+                    rewards=batch[schema[Columns.REWARDS]][i],
+                    terminated=(
+                        any(batch[schema[Columns.TERMINATEDS]][i])
+                        if schema[Columns.TERMINATEDS] in batch
+                        else any(batch["dones"][i])
+                    ),
+                    truncated=(
+                        any(batch[schema[Columns.TRUNCATEDS]][i])
+                        if schema[Columns.TRUNCATEDS] in batch
+                        else False
+                    ),
+                    # TODO (simon): Results in zero-length episodes in connector.
+                    # t_started=batch[Columns.T if Columns.T in batch else
+                    # "unroll_id"][i][0],
+                    # TODO (simon): Single-dimensional columns are not supported.
+                    # Extra model outputs might be serialized. We unserialize them here
+                    # if needed.
+                    # TODO (simon): Check, if we need here also reconversion from
+                    # JSONable in case of composite spaces.
+                    extra_model_outputs={
+                        k: unpack_if_needed(v[i])
+                        if k in input_compress_columns
+                        else v[i]
+                        for k, v in batch.items()
+                        if (
+                            k not in schema
+                            and k not in schema.values()
+                            and k not in ["dones", "agent_index", "type"]
+                        )
+                    },
+                    len_lookback_buffer=0,
+                )
+                # Finalize, if necessary.
+                # TODO (simon, sven): Check, if we should convert all data to lists
+                # before. Right now only obs are lists.
+                if finalize:
+                    episode.finalize()
+                episodes.append(episode)
+        # Note, `map_batches` expects a `Dict` as return value.
+        return {"episodes": episodes}

rllib/offline/tests/test_offline_data.py

@@ -46,6 +46,26 @@ def test_offline_convert_to_episodes(self):
         self.assertTrue(len(episodes) == 10)
         self.assertTrue(isinstance(episodes[0], SingleAgentEpisode))
 
+    def test_offline_convert_from_old_sample_batch_to_episodes(self):
+
+        base_path = Path(__file__).parents[2]
+        sample_batch_data_path = base_path / "tests/data/cartpole/large.json"
+        config = AlgorithmConfig().offline_data(
+            input_=["local://" + sample_batch_data_path.as_posix()],
+            input_read_method="read_json",
+            input_read_sample_batches=True,
+        )
+
+        offline_data = OfflineData(config)
+
+        batch = offline_data.data.take_batch(batch_size=10)
+        episodes = OfflinePreLearner._map_sample_batch_to_episode(False, batch)[
+            "episodes"
+        ]
+
+        self.assertTrue(len(episodes) == 10)
+        self.assertTrue(isinstance(episodes[0], SingleAgentEpisode))
+
     def test_sample(self):
 
         config = AlgorithmConfig().offline_data(input_=[self.data_path])

rllib/tuned_examples/bc/cartpole_bc.py

@@ -1,11 +1,11 @@
 from pathlib import Path
 
+from ray.air.constants import TRAINING_ITERATION
 from ray.rllib.algorithms.bc import BCConfig
 from ray.rllib.utils.metrics import (
     ENV_RUNNER_RESULTS,
     EPISODE_RETURN_MEAN,
     EVALUATION_RESULTS,
-    TRAINING_ITERATION_TIMER,
 )
 from ray.rllib.utils.test_utils import (
     add_rllib_example_script_args,
@@ -75,7 +75,7 @@
 
 stop = {
     f"{EVALUATION_RESULTS}/{ENV_RUNNER_RESULTS}/{EPISODE_RETURN_MEAN}": 120.0,
-    TRAINING_ITERATION_TIMER: 350.0,
+    TRAINING_ITERATION: 350,
 }
 
 if __name__ == "__main__":

rllib/tuned_examples/bc/pendulum_bc.py

@@ -1,11 +1,11 @@
 from pathlib import Path
 
+from ray.air.constants import TRAINING_ITERATION
 from ray.rllib.algorithms.bc import BCConfig
 from ray.rllib.utils.metrics import (
     ENV_RUNNER_RESULTS,
     EPISODE_RETURN_MEAN,
     EVALUATION_RESULTS,
-    TRAINING_ITERATION_TIMER,
 )
 from ray.rllib.utils.test_utils import (
     add_rllib_example_script_args,
@@ -61,7 +61,7 @@
 
 stop = {
     f"{EVALUATION_RESULTS}/{ENV_RUNNER_RESULTS}/{EPISODE_RETURN_MEAN}": -200.0,
-    TRAINING_ITERATION_TIMER: 350.0,
+    TRAINING_ITERATION: 350,
 }
 
 if __name__ == "__main__":