DesFaaS: Cross-Layer Joint Dynamic Deployment System for Serverless Stateful Functions

The on-demand resource model of serverless computing has driven its growing popularity. However, stateful applications require external mechanisms to manage their state, often through dynamic migration for resource allocation. This migration causes function locations to change dynamically, necessitating the scheduling of state data accordingly. Consequently, both stateful functions and their associated states must adapt efficiently to environmental changes-a co-adjustment relationship that is often overlooked or oversimplified in existing systems. Therefore, we design and build DesFaaS, a cross-layer joint dynamic deployment system, to provide an open source solution supporting real Kubernetes clusters for the runtime management of serverless stateful applications with variable locations. Specifically, first, we propose a cross-layer joint dynamic deployment framework, introducing three-layer hybrid migration media and designing a three-layer state management architecture. The designed automated management processes and interfaces support efficient function migration and state management under different load environments. Second, we propose an adaptive co-scheduling method for multi-function state data to optimize the access latency and resource utilization of state data in the system and support in-situ computing by collecting and analyzing the cost. Finally, we developed a prototype system, DesFaaS, and conducted real and simulated experiments, which demonstrated that DesFaaS has 19.36%, 39.06%, and 5.36% improvement in service performance, cost efficiency, and energy consumption compared with the state-of-the-art system.