Ah, standalone orchestrators. If you want to work on more complex serverless applications, the industry standard is to rent some tenant space for an orchestrator to handle crashes, retries, and exactly-once execution going according to plan. However, the cost of renting the space for a standalone orchestrator works against the efficiency and frugality of serverless, and when a controller like this is logically centralized, it limits how many application patterns it can support without extensive modification. Unum’s authors wonder if decentralizing the FaaS control structure can 1) accommodate the broad needs of complex serverless applications with minimal modification and 2) present a serverless computing schema for developers that actually is closer to the price point that providers claim it is. In this paper, they present the Unum system, a serverless library that bakes orchestration directly into instrumentation, rather than renting out space for an orchestrator whose application pattern coverage is pretty narrow. The authors also evaluated how Unum does with performance and cost of use as compared to traditional standalone orchestrators. Areas for future development of particular interest include developing a tracing system for Unum, adapting Unum for less statically defined control structures, and further investigation into how Unum can scale without issues.
Presenter: Sarah Abowitz