FnSched: An Efficient Scheduler for Serverless Functions

An imminent challenge in the serverless computing landscape is the escalating cost of infrastructure needed to handle the growing traffic at scale. This work presents FnSched, a function-level scheduler designed to minimize provider resource costs while meeting customer performance requirements. FnSched works by carefully regulating the resource usage of colocated functions on each invoker, and autoscaling capacity by concentrating load on few invokers in response to varying traffic. We implement a prototype of FnSched and show that, compared to existing baselines, FnSched significantly improves resource efficiency, by as much as 36%-55%, while providing acceptable application latency.