Elixir: An Agent for Supporting Elasticity in Docker Swarm

Abstract

Elixir is an autonomous agent that extends the capabilities of Docker Swarm in certain ways: (a) it supports monitoring of resources in real-time, (b) introduces a scheduler for balancing the workload among swarm nodes and, most importantly, (c) supports automatic scaling-up (or down) of worker nodes at run-time with no downtime (i.e. without stopping the system). The proposed scaling strategy is reactive and works by responding to static (pre-defined) thresholds applying on resource metrics (e.g. RAM, CPU). The experimental results demonstrate that Docker Swarm with Elixir responds to the increasing (or decreasing) resource demands of each application leading to significantly faster response times compared to its non-auto scaled counterpart, while maintaining optimal allocation of resources per application.