On the Benefit of Virtualization: Strategies for Flexible Server Allocation

TL;DR

This paper explores how network virtualization enables dynamic server allocation strategies that improve Quality-of-Service by adapting to changing demand and request origins, demonstrating significant benefits especially in moderately dynamic environments.

Contribution

It introduces online and offline algorithms for flexible server placement, quantifies the advantages over static systems, and analyzes the impact of demand variability on performance.

Findings

Flexible server allocation significantly reduces latency.

Dynamic strategies outperform static ones in moderate-demand scenarios.

Simulation confirms substantial benefits of virtualization-based resource management.

Abstract

Virtualization technology facilitates a dynamic, demand-driven allocation and migration of servers. This paper studies how the flexibility offered by network virtualization can be used to improve Quality-of-Service parameters such as latency, while taking into account allocation costs. A generic use case is considered where both the overall demand issued for a certain service (for example, an SAP application in the cloud, or a gaming application) as well as the origins of the requests change over time (e.g., due to time zone effects or due to user mobility), and we present online and optimal offline strategies to compute the number and location of the servers implementing this service. These algorithms also allow us to study the fundamental benefits of dynamic resource allocation compared to static systems. Our simulation results confirm our expectations that the gain of flexible server allocation is particularly high in scenarios with moderate dynamics.