A Seer Knows Best: Optimized Object Storage Shuffling for Serverless Analytics

Serverless platforms offer high resource elasticity and pay-as-you-go billing, making them a compelling choice for data analytics. To craft a "pure" serverless solution, the common practice is to transfer intermediate data between serverless functions via serverless object storage (IBM COS; AWS S3). However, prior works have led to inconclusive results about the performance of object storage, since they have left large margin for optimization. To verify that object storage has been underrated, we design a novel shuffle manager for serverless data analytics termed Seer. Specifically, Seer dynamically chooses between two shuffle algorithms to maximize performance. The algorithm choice is based on some predictive models, and very importantly, without users having to specify intermediate data sizes at the time of the job submission. We integrate Seer with PyWren-IBM [31], a serverless analytics framework, and evaluate it against both serverful (e.g., Spark) and serverless systems (e.g., Google BigQuery). Our results certify that our new shuffle manager can deliver performance improvements over them.