composer.datasets.build_streaming_c4_dataloader(global_batch_size, remote='s3://mosaicml-internal-dataset-c4/mds/2/', local='/tmp/mds-cache/mds-c4/', split='train', shuffle=True, drop_last=True, tokenizer_name='bert-base-uncased', max_seq_len=512, group_method='truncate', mlm=False, mlm_probability=0.15, predownload=100000, keep_zip=None, download_retry=2, download_timeout=60, validate_hash=None, shuffle_seed=None, num_canonical_nodes=None, **dataloader_kwargs)[source]#

Builds a DataSpec for the StreamingC4 (Colossal Cleaned Common Crawl) dataset.

  • global_batch_size (int) โ€“ Global batch size.

  • remote (str) โ€“ Remote directory (S3 or local filesystem) where dataset is stored. Default: 's3://mosaicml-internal-dataset-c4/mds/2/'

  • local (str) โ€“ Local filesystem directory where dataset is cached during operation. Default: '/tmp/mds-cache/mds-c4/'

  • split (str) โ€“ What split of the dataset to use. Either 'train' or 'val'. Default: 'train'.

  • shuffle (bool) โ€“ whether to shuffle the dataset. Default: True.

  • drop_last (bool) โ€“ whether to drop last samples. Default: True.

  • tokenizer_name (str) โ€“ The name of the HuggingFace tokenizer to preprocess text with. Default: 'bert-base-uncased'.

  • max_seq_len (int) โ€“ The max sequence length of each token sample. Default: 512.

  • group_method (str) โ€“ How to group text samples into token samples. Currently only truncate is supported.

  • mlm (bool) โ€“ Whether or not to use masked language modeling. Default: False.

  • mlm_probability (float) โ€“ If mlm==True, the probability that tokens are masked. Default: 0.15.

  • predownload (int, optional) โ€“ Target number of samples ahead to download the shards of while iterating. Defaults to 100_000.

  • keep_zip (bool, optional) โ€“ Whether to keep or delete the compressed file when decompressing downloaded shards. If set to None, keep iff remote is local. Defaults to None.

  • download_retry (int) โ€“ Number of download re-attempts before giving up. Defaults to 2.

  • download_timeout (float) โ€“ Number of seconds to wait for a shard to download before raising an exception. Defaults to 60.

  • validate_hash (str, optional) โ€“ Optional hash or checksum algorithm to use to validate shards. Defaults to None.

  • shuffle_seed (int, optional) โ€“ Seed for shuffling, or None for random seed. Defaults to None.

  • num_canonical_nodes (int, optional) โ€“ Canonical number of nodes for shuffling with resumption. Defaults to None, which is interpreted as the number of nodes of the initial run.

  • **dataloader_kwargs (Dict[str, Any]) โ€“ Additional settings for the dataloader (e.g. num_workers, etc.)