Characterization of Software Aging Effects in Elastic Storage Mechanisms for Private Clouds

Cloud computing systems fundamentally provide access to large pools of data and computational resources. Eucalyptus is a software framework used to implement private and hybrid-style Infrastructure as a Service clouds. It implements the Amazon Web Service (AWS) API, allowing interoperability with other AWS-based services. Elastic block storage (EBS) is a technology which provides flexible allocation of remote storage volumes to the virtual machines running in a cloud computing environment. Eucalyptus interacts with many software components to provide EBS features to the virtual machines: KVM hypervisor and Eucalyptus Node Controller (NC) are among those components. This work investigates the software aging effects in a Eucalyptus environment, considering workloads composed of intensive requests for attaching remote storage volumes to virtual machines. The results evidenced that memory leaks in Node Controller and the high CPU utilization by the KVM process are strongly correlated. The experimental analysis also show how much the aging effects are related to the performance degradation of a virtualized web server running on this infrastructure.