Mitigating interference in cloud services by middleware reconfiguration

Abstract

Application performance has been and remains one of top five concerns since the inception of cloud computing. A primary determinant of application performance is multi- tenancy or sharing of hardware resources in clouds. While some hardware resources can be partitioned well among VMs (such as CPUs), many others cannot (such as memory band- width). In this paper, we focus on understanding the vari- ability in application performance on a cloud and explore ways for an end customer to deal with it. Based on rigor- ous experiments using CloudSuite, a popular Web2.0 bench- mark, running on EC2, we found that interference-induced performance degradation is a reality. On a private cloud testbed, we also observed that interference impacts the choice of best configuration values for applications and middleware. We posit that intelligent reconfiguration of application pa- rameters presents a way for an end customer to reduce the impact of interference. However, tuning the application to deal with interference is challenging because of two funda- mental reasons - the configuration depends on the nature and degree of interference and there are inter-parameter dependencies. We design and implement the IC2 system (Interference-aware Cloud application Configuration) to ad- dress the challenges of detection and mitigation of performance interference in clouds. Compared to an interference- agnostic configuration, the proposed solution provides up to 29% and 40% improvement in average response time on EC2 and a private cloud testbed respectively.