RISCLESS: A Reinforcement Learning Strategy to Exploit Unused Cloud Resources

TL;DR

RISCLESS is a reinforcement learning strategy that optimizes the use of unused cloud resources, balancing SLA guarantees and cost reduction by intelligently allocating stable resources alongside volatile ones.

Contribution

It introduces a novel RL-based approach that dynamically allocates stable resources to exploit unused cloud capacity while maintaining SLA guarantees.

Findings

Increased profits by 15.9% on average.

Reduced SLA violation time by 36.7%.

Used 19.5% more ephemeral resources.

Abstract

One of the main objectives of Cloud Providers (CP) is to guarantee the Service-Level Agreement (SLA) of customers while reducing operating costs. To achieve this goal, CPs have built large-scale datacenters. This leads, however, to underutilized resources and an increase in costs. A way to improve the utilization of resources is to reclaim the unused parts and resell them at a lower price. Providing SLA guarantees to customers on reclaimed resources is a challenge due to their high volatility. Some state-of-the-art solutions consider keeping a proportion of resources free to absorb sudden variation in workloads. Others consider stable resources on top of the volatile ones to fill in for the lost resources. However, these strategies either reduce the amount of reclaimable resources or operate on less volatile ones such as Amazon Spot instance. In this paper, we proposed RISCLESS, a Reinforcement Learning strategy to exploit unused Cloud resources. Our approach consists of using a small proportion of stable on-demand resources alongside the ephemeral ones in order to guarantee customers SLA and reduce the overall costs. The approach decides when and how much stable resources to allocate in order to fulfill customers' demands. RISCLESS improved the CPs' profits by an average of 15.9% compared to state-of-the-art strategies. It also reduced the SLA violation time by an average of 36.7% while increasing the amount of used ephemeral resources by 19.5% on average