In real-world machine learning (ML) pipelines, datasets are continuously growing. Models must incorporate this new training data to improve generalization and adapt to potential distribution shifts. The cost of model retraining is proportional to how frequently the model is retrained and how much data it is trained on, which makes the naive approach of retraining from scratch each time impractical. We present Modyn, a data-centric end-to-end machine learning platform. Modyn's ML pipeline abstraction enables users to declaratively describe policies for continuously training a model on a growing dataset. Modyn pipelines allow users to apply data selection policies (to reduce the number of data points) and triggering policies (to reduce the number of trainings). Modyn executes and orchestrates these continuous ML training pipelines. The system is open-source and comes with an ecosystem of benchmark datasets, models, and tooling. We formally discuss how to measure the performance of ML pipelines by introducing the concept of composite models, enabling fair comparison of pipelines with different data selection and triggering policies. We empirically analyze how various data selection and triggering policies impact model accuracy, and also show that Modyn enables high throughput training with sample-level data selection.

GPUs are critical for maximizing the throughput-per-Watt of deep neural network (DNN) applications. However, DNN applications often underutilize GPUs, even when using large batch sizes and eliminating input data processing or communication stalls. DNN workloads consist of data-dependent operators, with different compute and memory requirements. While an operator may saturate GPU compute units or memory bandwidth, it often leaves other GPU resources idle. Despite the prevalence of GPU sharing techniques, current approaches are not sufficiently fine-grained or interference-aware to maximize GPU utilization while minimizing interference at the granularity of 10s of μs. We propose Orion, a system that transparently intercepts GPU kernel launches from multiple clients sharing a GPU. Orion schedules work on the GPU at the granularity of individual operators and minimizes interference by taking into account each operator's compute and memory requirements. We integrate Orion in PyTorch and demonstrate its benefits in various DNN workload collocation use cases. Orion significantly improves tail latency compared to state-of-the-art baselines for a high-priority inference job while collocating best-effort inference jobs to increase per-GPU request throughput by up to 7.3×, or while collocating DNN training, saving up to 1.49× in training costs compared to dedicated GPU allocation.