separate out train and eval dataset streaming

This commit is contained in:
Dan Saunders
2025-08-20 05:17:05 +00:00
parent 10335d5df9
commit 2176962231
4 changed files with 135 additions and 64 deletions

View File

@@ -44,6 +44,48 @@ from axolotl.utils.trainer import (
LOG = get_logger(__name__)
def _is_streaming_enabled_for_split(
cfg: DictDefault, split: Literal["train", "test"]
) -> bool:
"""Check if streaming is enabled for a specific split."""
if split == "test":
# For eval datasets, check eval_streaming first, then fall back to streaming
eval_streaming = cfg.get("eval_streaming")
if eval_streaming is not None:
return eval_streaming
# Fall back to main streaming setting
streaming = cfg.get("streaming")
if streaming is True:
return True
# Check if pretraining dataset exists (defaults to streaming)
has_pretraining = cfg.get("pretraining_dataset") is not None
streaming_default_for_pretraining = has_pretraining and streaming is None
return streaming_default_for_pretraining
def _get_streaming_config_for_split(
cfg: DictDefault, split: Literal["train", "test"]
) -> DictDefault:
"""Get a modified config object with split-specific streaming settings."""
if split != "test":
return cfg
# Override with eval-specific configs if they exist
streaming_cfg = DictDefault(cfg)
eval_strategy = cfg.get("eval_streaming_dataset_mixing_strategy")
eval_weights = cfg.get("eval_streaming_mixing_weights")
if eval_strategy is not None:
streaming_cfg["streaming_dataset_mixing_strategy"] = eval_strategy
if eval_weights is not None:
streaming_cfg["streaming_mixing_weights"] = eval_weights
return streaming_cfg
@retry_on_request_exceptions(max_retries=3, delay=5)
def prepare_datasets(
cfg: DictDefault,
@@ -267,10 +309,14 @@ def _load_tokenized_prepared_datasets(
datasets_configs = cfg.datasets if split == "train" else cfg.test_datasets
prompters: list[Prompter | None] = []
# For streaming datasets, skip caching and load raw datasets directly
if cfg.streaming:
# Check if streaming is enabled for this split
use_streaming = _is_streaming_enabled_for_split(cfg, split)
if use_streaming:
# For streaming datasets, skip caching and load raw datasets directly
streaming_cfg = _get_streaming_config_for_split(cfg, split)
dataset, prompters = _load_raw_datasets(
cfg,
streaming_cfg,
datasets_configs,
tokenizer,
split,

View File

@@ -550,10 +550,7 @@ def merge_datasets(
return ds
return ds.shuffle(seed=cfg.seed)
# Check if we have any IterableDatasets
has_iterable = any(isinstance(ds, IterableDataset) for ds in datasets)
if has_iterable:
if any(isinstance(ds, IterableDataset) for ds in datasets):
LOG.info("Merging streaming datasets...")
merged_dataset = _merge_streaming_datasets(datasets, cfg)
else:

View File

@@ -935,7 +935,13 @@ class AxolotlInputConfig(
streaming: bool | None = Field(
default=None,
json_schema_extra={
"description": "Whether to use streaming datasets (IterableDataset) for processing large datasets that don't fit in memory. When True, data is loaded on-demand during training without upfront preprocessing. Requires max_steps to be set. Pre-training datasets default to streaming unless explicitly set to False."
"description": "Whether to use streaming datasets (IterableDataset) for training datasets. When True, data is loaded on-demand during training without upfront preprocessing. Requires max_steps to be set. Pre-training datasets default to streaming unless explicitly set to False."
},
)
eval_streaming: bool | None = Field(
default=None,
json_schema_extra={
"description": "Whether to use streaming datasets for evaluation datasets. If not set, falls back to the 'streaming' setting. Useful for streaming large training data while keeping smaller eval datasets in memory."
},
)
streaming_dataset_mixing_strategy: str | None = Field(
@@ -950,6 +956,18 @@ class AxolotlInputConfig(
"description": "Weights for weighted mixing strategy when using multiple streaming datasets. Must sum to 1.0 and have same length as datasets list. Only used when streaming_dataset_mixing_strategy='weighted'."
},
)
eval_streaming_dataset_mixing_strategy: str | None = Field(
default=None,
json_schema_extra={
"description": "Strategy for mixing multiple streaming evaluation datasets. If not set, falls back to streaming_dataset_mixing_strategy. Options: 'round_robin', 'weighted', 'random'."
},
)
eval_streaming_mixing_weights: list[float] | None = Field(
default=None,
json_schema_extra={
"description": "Weights for weighted mixing strategy for evaluation datasets. Must sum to 1.0 and have same length as evaluation datasets list."
},
)
# INTERNALS - document for now, generally not set externally
is_preprocess: bool | None = None

View File

@@ -1388,20 +1388,29 @@ class GRPOVllmValidationMixin:
class StreamingValidationMixin:
"""Validation methods related to streaming datasets."""
@model_validator(mode="after")
def check_streaming_requires_max_steps(self):
"""Ensure max_steps is set when using streaming datasets."""
# Check if streaming is explicitly enabled
streaming_enabled = getattr(self, "streaming", None) is True
def _is_streaming_enabled(self, context: str = "train") -> bool:
"""Check if streaming is enabled for a given context (train or eval)."""
if context == "eval":
eval_streaming = getattr(self, "eval_streaming", None)
if eval_streaming is not None:
return eval_streaming
# Fall back to main streaming setting
streaming = getattr(self, "streaming", None)
if streaming is True:
return True
# Check if pretraining dataset exists (defaults to streaming)
has_pretraining = getattr(self, "pretraining_dataset", None) is not None
streaming_default_for_pretraining = (
has_pretraining and getattr(self, "streaming", None) is None
)
streaming_default_for_pretraining = has_pretraining and streaming is None
# If streaming is enabled (explicitly or by default for pretraining)
if streaming_enabled or streaming_default_for_pretraining:
return streaming_default_for_pretraining
@model_validator(mode="after")
def check_streaming_requires_max_steps(self):
"""Ensure max_steps is set when using streaming datasets."""
# Check if streaming is enabled for training datasets
if self._is_streaming_enabled("train"):
max_steps = getattr(self, "max_steps", None)
if not max_steps:
raise ValueError("max_steps must be set when using streaming datasets")
@@ -1411,17 +1420,8 @@ class StreamingValidationMixin:
@model_validator(mode="after")
def check_streaming_validation_splits_conflict(self):
"""Ensure validation splits are not used with streaming datasets."""
# Check if streaming is explicitly enabled
streaming_enabled = getattr(self, "streaming", None) is True
# Check if pretraining dataset exists (defaults to streaming)
has_pretraining = getattr(self, "pretraining_dataset", None) is not None
streaming_default_for_pretraining = (
has_pretraining and getattr(self, "streaming", None) is None
)
# If streaming is enabled (explicitly or by default for pretraining)
if streaming_enabled or streaming_default_for_pretraining:
# Check if streaming is enabled for training datasets
if self._is_streaming_enabled("train"):
val_set_size = getattr(self, "val_set_size", 0.0)
if val_set_size and val_set_size > 0:
raise ValueError(
@@ -1433,17 +1433,8 @@ class StreamingValidationMixin:
@model_validator(mode="after")
def check_streaming_preprocessing_conflict(self):
"""Ensure preprocessing is not enabled with streaming datasets."""
# Check if streaming is explicitly enabled
streaming_enabled = getattr(self, "streaming", None) is True
# Check if pretraining dataset exists (defaults to streaming)
has_pretraining = getattr(self, "pretraining_dataset", None) is not None
streaming_default_for_pretraining = (
has_pretraining and getattr(self, "streaming", None) is None
)
# If streaming is enabled (explicitly or by default for pretraining)
if streaming_enabled or streaming_default_for_pretraining:
# Check if streaming is enabled for training or eval datasets
if self._is_streaming_enabled("train") or self._is_streaming_enabled("eval"):
if os.environ.get("AXOLOTL_IS_PREPROCESS") == "1":
raise ValueError("preprocess is not supported for streaming datasets")
@@ -1452,17 +1443,8 @@ class StreamingValidationMixin:
@model_validator(mode="after")
def check_streaming_skip_prepare_dataset(self):
"""Ensure skip_prepare_dataset is set for streaming datasets."""
# Check if streaming is explicitly enabled
streaming_enabled = getattr(self, "streaming", None) is True
# Check if pretraining dataset exists (defaults to streaming)
has_pretraining = getattr(self, "pretraining_dataset", None) is not None
streaming_default_for_pretraining = (
has_pretraining and getattr(self, "streaming", None) is None
)
# If streaming is enabled (explicitly or by default for pretraining)
if streaming_enabled or streaming_default_for_pretraining:
# Check if streaming is enabled for training or eval datasets
if self._is_streaming_enabled("train") or self._is_streaming_enabled("eval"):
skip_prepare = getattr(self, "skip_prepare_dataset", None)
if skip_prepare is False:
LOG.warning(
@@ -1476,45 +1458,73 @@ class StreamingValidationMixin:
@model_validator(mode="after")
def check_streaming_mixing_weights(self):
"""Validate streaming_mixing_weights configuration."""
valid_strategies = ["round_robin", "weighted", "random"]
# Check main strategy and weights
strategy = getattr(self, "streaming_dataset_mixing_strategy", "round_robin")
weights = getattr(self, "streaming_mixing_weights", None)
self._validate_streaming_strategy_and_weights(
strategy,
weights,
"streaming_dataset_mixing_strategy",
"streaming_mixing_weights",
valid_strategies,
)
# Validate strategy values
valid_strategies = ["round_robin", "weighted", "random"]
# Check eval-specific strategy and weights
eval_strategy = getattr(self, "eval_streaming_dataset_mixing_strategy", None)
eval_weights = getattr(self, "eval_streaming_mixing_weights", None)
if eval_strategy is not None:
self._validate_streaming_strategy_and_weights(
eval_strategy,
eval_weights,
"eval_streaming_dataset_mixing_strategy",
"eval_streaming_mixing_weights",
valid_strategies,
)
elif eval_weights is not None:
LOG.warning(
"eval_streaming_mixing_weights provided but eval_streaming_dataset_mixing_strategy is not set. "
"Weights will be ignored unless eval_streaming_dataset_mixing_strategy='weighted'."
)
return self
def _validate_streaming_strategy_and_weights(
self, strategy, weights, strategy_field, weights_field, valid_strategies
):
"""Helper method to validate strategy and weights pair."""
if strategy not in valid_strategies:
raise ValueError(
f"streaming_dataset_mixing_strategy must be one of {valid_strategies}, "
f"{strategy_field} must be one of {valid_strategies}, "
f"got '{strategy}'"
)
if strategy == "weighted":
if weights is None:
raise ValueError(
"streaming_mixing_weights must be provided when "
"streaming_dataset_mixing_strategy='weighted'"
f"{weights_field} must be provided when "
f"{strategy_field}='weighted'"
)
if not isinstance(weights, list) or not all(
isinstance(w, (int, float)) for w in weights
):
raise ValueError("streaming_mixing_weights must be a list of numbers")
raise ValueError(f"{weights_field} must be a list of numbers")
if any(w < 0 for w in weights):
raise ValueError("streaming_mixing_weights must be non-negative")
raise ValueError(f"{weights_field} must be non-negative")
if abs(sum(weights) - 1.0) > 1e-6:
raise ValueError(
f"streaming_mixing_weights must sum to 1.0, got {sum(weights)}"
)
raise ValueError(f"{weights_field} must sum to 1.0, got {sum(weights)}")
elif weights is not None and strategy != "weighted":
LOG.warning(
f"streaming_mixing_weights provided but strategy is '{strategy}'. "
f"{weights_field} provided but {strategy_field} is '{strategy}'. "
"Weights will be ignored."
)
return self
# pylint: disable=too-many-ancestors
class ValidationMixin(