Serverless execution of scientific workflows: Experiments with HyperFlow, AWS Lambda and Google Cloud Functions 

Malawski, Maciej; Gajek, Adam; Zima, Adam; Balis, Bartosz; Figiela, Kamil

Scientific workflows consisting of a high number of interdependent tasks represent an important class of complex scientific applications. Recently, a new type of serverless infrastructures has emerged, represented by such services as Google Cloud Functions and AWS Lambda, also referred to as the Function-as-a-Service model. In this paper we take a look at such serverless infrastructures, which are designed mainly for processing background tasks of Web and Internet of Things applications, or event-driven stream processing. We evaluate their applicability to more compute- and data-intensive scientific workflows and discuss possible ways to repurpose serverless architectures for execution of scientific workflows. We have developed prototype workflow executor functions using AWS Lambda and Google Cloud Functions, coupled with the HyperFlow workflow engine. These functions can run workflow tasks in AWS and Google infrastructures, and feature such capabilities as data staging to/from S3 or Google Cloud Storage and execution of custom application binaries. We have successfully deployed and executed the Montage astronomy workflow, often used as a benchmark, and we report on initial results of its performance evaluation. Our findings indicate that the simple mode of operation makes this approach easy to use, although there are costs involved in preparing portable application binaries for execution in a remote environment.While our solution is an early prototype, we find the presented approach highly promising. We also discuss possible future steps related to execution of scientific workflows in serverless infrastructures. Finally, we perform a cost analysis and discuss implications with regard to resource management for scientific applications in general.