CWASI: A WebAssembly Runtime Shim for Inter-Function Communication in the Serverless Edge-Cloud Continuum

2023-12-06

IFIP International Information Security Conference

AI Summary

To address high latency and network overhead caused by frequent inter-function data exchange relying on remote storage in edge–cloud serverless continua, this paper proposes Shim, a location-aware WebAssembly runtime. Shim introduces a novel tri-modal communication model—local, proximal, and remote—and is the first OCI-compliant WASI runtime to enable dynamic, adaptive communication-path selection and transparent optimization. By deeply integrating function hosting mechanisms with location-aware routing, Shim achieves up to 95% reduction in inter-function communication latency and a 30× throughput improvement in co-located deployments. These gains significantly alleviate cross-layer network dependency and transmission overhead. The work establishes a new paradigm for efficient data exchange in serverless architectures operating across edge and cloud environments.

Technology Category

• Machine Learning: Learning on the Edge & Model Compression
• Multiagent Systems: Agent Communication
• Planning, Routing, and Scheduling: Planning with Language Models

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Economics, Online Markets and Human Computation: The sharing economy

Abstract

Serverless Computing brings advantages to the Edge-Cloud contin-uum, like simplified programming and infrastructure management. In composed workflows, where serverless functions need to exchange data constantly, serverless platforms rely on remote services such as object storage and key-value stores as a common approach to exchange data. In WebAssembly, functions leverage WebAssembly System Interface to connect to the network and exchange data via remote services. As a consequence, co-located serverless functions need remote services to exchange data, increasing latency and adding network overhead. To mitigate this problem, in this paper, we intro-duce CWASI: a WebAssembly OCI-compliant runtime shim that determines the best inter-function data exchange approach based on the serverless function locality. CWASI introduces a three-mode communication model for the Serverless Edge-Cloud continuum. This communication model enables CWASI Shim to optimize inter-function communication for co-located functions by leveraging the function host mechanisms. Experimental results show that CWASI reduces the communication latency between the co-located serverless functions by up to 95% and increases the communication throughput by up to 30x.

Problem

• Reduces latency in serverless inter-function communication
• Eliminates remote service dependency for co-located functions
• Optimizes data exchange in Edge-Cloud continuum workflows

Innovation

• WebAssembly OCI-compliant runtime shim
• Three-mode communication model
• Optimizes inter-function communication locality