Towards Federated Foundation Models: Scalable Dataset Pipelines for Group-Structured Learning

We introduce a library, Dataset Grouper, to create large-scale group-structured (e.g., federated) datasets, enabling federated learning simulation at the scale of foundation models. This library allows the creation of group-structured versions of existing datasets based on user-specified partitions, and directly leads to a variety of useful heterogeneous datasets that can be plugged into existing software frameworks. Dataset Grouper offers three key advantages. First, it scales to settings where even a single group's dataset is too large to fit in memory. Second, it provides flexibility, both in choosing the base (non-partitioned) dataset and in defining partitions. Finally, it is framework-agnostic. We empirically demonstrate that Dataset Grouper allows for large-scale federated language modeling simulations on datasets that are orders of magnitude larger than in previous work. Our experimental results show that algorithms like FedAvg operate more as meta-learning methods than as empirical risk minimization methods at this scale, suggesting their utility in downstream personalization and task-specific adaptation.