Estimating Function Completion Time Distribution in Open Source FaaS

Function as a Service (FaaS) is the newest stage of application virtualization. Several public cloud providers offer FaaS solutions, however, the open source community also embraced this technology. In this paper we introduce a Python based function run-time, applicable in open source FaaS platforms for latency sensitive compute intensive applications that reduces the maximum completion times by taking into account the number of CPU cores. We also present our simulator that estimates the distribution of the completion times for compute intensive functions, when our proposed function run-time is in use. We present the results of our simulator by using two compute intensive functions. We also show a scenario when the user function is not purely compute intensive.