WebGraphMix

Official code release for Hubs or Fringes? Pretraining Data Selection via Web Graph Centrality [Paper][Project Page].

WebGraphMix uses structural centrality scores over the Common Crawl host-level web graph to construct pretraining mixtures of central vs. peripheral documents. This repository contains the graph pipeline, importance-sampling scripts, and a slim DataComp-LM (DCLM) fork for training and evaluation at 400M and 1B scales.

• HuggingFace (centrality scores): PrincetonPLI/cc-centrality-scores
• HuggingFace (1B checkpoints): PrincetonPLI/WebGraphMix-openlm-1B
• Base corpus: WebOrganizer/Corpus-200B
• WebOrganizer 1B baseline weights: download from the WebOrganizer HuggingFace collection

Quick start: evaluate a checkpoint

# 1. Setup
conda env create -f environment.yml
conda activate webgraphmix
cd dclm && pip install -e . && cd ..

# 2. Download a pretrained 1B checkpoint
./experiments/artifacts/download.sh checkpoints

# 3. Evaluate default model on DCLM CORE v2 (23 tasks)
export REPO_ROOT=$(pwd)
./experiments/eval/mmlu_and_lowvar.sh                    # betweenness_alpha0.5
# ./experiments/eval/mmlu_and_lowvar.sh random_selection  # other HF checkpoints

# 4. Aggregate scores into a comparison sheet
cd dclm/exp_data/evals && python benchmark_score_comparison.py

Environment variables

Variable	Default	Purpose
REPO_ROOT	repo root	Code and centrality scores
DATA_ROOT	$REPO_ROOT/corpus_200b	Corpus-200B local copy
HF_HOME	~/.cache/huggingface	Tokenizer and HF models

Path helpers live in lib/paths.py and are used across the pipeline scripts.

Full reproduction pipeline

Prerequisites

1. Corpus-200B (~hundreds of GB): download from WebOrganizer/Corpus-200B into $DATA_ROOT.
2. DCLM-fasttext quality scores: included in Corpus-200B as scores_dclm-fasttext/ shards, or regenerate via dclm/baselines/.
3. GPU: centrality computation needs GPUs with cuGraph; or download precomputed scores (recommended).

Step-by-step

1. Download CC host graph          python pipeline/graph/download_host_graph.py
2. Build corpus host graph         python pipeline/graph/build_host_graph.py
3. Compute centrality (optional)   python pipeline/graph/centrality/compute_{katz,betweenness,eigenvector}.py
                                   OR: ./experiments/artifacts/download.sh centrality
4. Generate annotations            python pipeline/annotations/centrality_topk.py --centrality-metric betweenness
5. Importance-sample documents     ./pipeline/sampling/run_sampling_job.sh  (see script for env vars)
6. Tokenize + shuffle              dclm/rust_processing/tokshuf-rs/run_rust_tokenizer.sh
7. Register dataset JSON           dclm/exp_data/datasets/tokenized/ (examples included)
8. Train OpenLM                    ./experiments/train/betweenness_50top.sh
9. Evaluate                        ./experiments/eval/mmlu_and_lowvar.sh
10. Convert to HF (optional)        python dclm/convert_openlm_to_hf_1b.py

Headline 1B experiments (Table 1)

Method	HF checkpoint / model JSON	Train script	Dataset JSON
Random baseline	random_selection	experiments/train/random.sh	baseline_random_corpus_32b.json
Quality (DCLM-fasttext)	dclm_fasttext_only	experiments/train/quality.sh	quality_only_dclmfilter_corpus_32b.json
WebGraphMix (50/50 betweenness)	betweenness_alpha0.5	experiments/train/betweenness_50top.sh	betweenness_50top_corpus_32b.json
WebGraphMix+ (multiply 50top)	betweenness_alpha0.5_mult_div_dclm_fasttext	experiments/train/multiply_betweenness_50top.sh	centrality_dclmfilter_multiply/regular_bottomk/betweenness_50top_corpus_32b.json

Training uses torchrun -m training.train with scale 1b_1x_fast (~28B tokens). See dclm/training/configs/ for 400M (411m_1x) settings.

Repository layout

WebGraphMix/
├── lib/
│   └── paths.py                    # Central path configuration (REPO_ROOT, DATA_ROOT, etc.)
├── pipeline/
│   ├── graph/
│   │   ├── download_host_graph.py  # Download CC host-graph shards
│   │   ├── build_host_graph.py     # Intersect CC graph with corpus hosts
│   │   ├── check_corpus_overlap.py
│   │   ├── doc_counts_by_host.py
│   │   ├── data/commoncrawl/       # CC graph path index files (small; large downloads gitignored)
│   │   └── centrality/             # GPU centrality scripts + precomputed scores (HF)
│   ├── annotations/                # Per-document annotation generation
│   └── sampling/
│       ├── select_training_data.py # Importance-based document sampling
│       └── run_sampling_job.sh
├── experiments/
│   ├── train/                      # Headline 1B training launchers
│   ├── eval/                       # DCLM CORE v2 evaluation
│   └── artifacts/                  # HuggingFace download/upload helpers
└── dclm/                           # DCLM fork: training, eval, tokshuf-rs

Precomputed artifacts (HuggingFace)

Download instead of recomputing:

./experiments/artifacts/download.sh all

Artifact	Size (approx.)	Contents
Centrality scores	~1.8 GB	host_graph_scores_{betweenness,katz,eigenvector}_*.json
1B checkpoints	~17 GB each	random, quality, betweenness 50/50, multiply 50/50

To upload (maintainers):

./experiments/artifacts/upload.sh all

Known issues

• tokshuf local cells: Create a temp directory (e.g. tokshuf_tmp/) via LOCAL_CELL_DIR; do not commit these directories.

Citation

@article{badoni2026webgraphmix,
  title={Hubs or Fringes: Pretraining Data Selection via Web Graph Centrality},
  author={Badoni, Vedant and Chen, Danqi and Wang, Xinyi},
  year={2026}
}

License

The dclm/ subdirectory follows the DCLM license. WebGraphMix-specific scripts are released under the same terms unless otherwise noted.