PDL Abstract

Varuna: Scalable, Low-cost Training of Massive Deep Learning Models

EuroSys ’22, April 5-8, 2022, Rennes, France. BEST PAPER AWARD!

Sanjith Athlur†, Nitika Saran‡, Muthian Sivathanu*, Ramachandran Ramjee*, Nipun Kwatra*

† Carnegie Mellon University
‡ Cornell University
* Microsoft Research, Bangalore, India

Systems for training massive deep learning models (billions of parameters) today assume and require specialized "hyperclusters": hundreds or thousands of GPUs wired with specialized high-bandwidth interconnects such as NV-Link and Infiniband. Besides being expensive, such dependence on hyperclusters and custom high-speed inter-connects limits the size of such clusters, creating (a) scalability limits on job parallelism; (b) resource fragmentation across hyperclusters.

In this paper,we present Varuna a newsystem that enables training massive deep learning models on commodity networking. Varuna makes thrifty use of networking resources and automatically configures the user’s training job to efficiently use any given set of resources. Therefore, Varuna is able to leverage łlow-priority" VMs that cost about 5x cheaper than dedicated GPUs, thus significantly reducing the cost of training massive models.We demonstrate the efficacy of Varuna by training massive models, including a 200 billion parameter model, on 5x cheaper łspot VMs", while maintaining high training throughput. Varuna improves end-to-end training time for language models like BERT and GPT-2 by up to 18x compared to other model-parallel approaches and up to 26% compared to other pipeline parallel approaches on commodity VMs.

The code for Varuna is available at microsoft/varuna.