Virtualizing resources for easy pooling and accounting, as well as for rapid provisioning and release, is essential for the effective management of modern data centers. Although the compute and storage resources can be virtualized quite effectively, a comprehensive solution for network virtualization has yet to be developed. Our analysis of the requirements for a comprehensive network virtualization solution identified two complimentary steps of ultimate importance. One is specifying the network-related requirements, another is carrying out the requirements of multiple independent tenants in an efficient and scalable manner. We introduce a novel intent-based modeling abstraction for specifying the network as a policy governed service and present an efficient network virtualization architecture, Distributed Overlay Virtual Ethernet network (DOVE), realizing the proposed abstraction. We describe the working prototype of DOVE architecture and report the results of the extensive simulation-based performance study, demonstrating the scalability and the efficiency of the solution.

The authors consider elastic multi-VM workloads corresponding to multi-tier application and study the fundamental problems of VM placement optimization, subject to policy constraints, elasticity requirements, and performance SLAs. Numerous algorithmic and architecture proposals appeared recently in the area of resource provisioning in IaaS. The chapter provides a comprehensive review of related work in this field and presents the authors’ recent scientific findings in this area obtained in the framework of an EU funded project, RESERVOIR. The chapter discusses horizontal elasticity support in IaaS, its relationship to SLA protection, VM placement optimization and efficient capacity management to improve cost-efficiency of cloud providers. Elastic services comprise multiple virtualized resources that can be added and deleted on demand to match variability in the workload. A Service owner profiles the service to determine its most appropriate sizing under different workload conditions. This variable sizing is formalized through a service level agreement (SLA) between the service owner and the cloud provider. The Cloud provider obtains maximum benefit when it succeeds to fully allocate the resource set demanded by the elastic service subject to its SLA. Failure to do so may result in SLA breach and financial losses to the provider. The chapter defines a novel combinatorial optimization problem called elastic services placement problem to maximize the provider’s benefit from SLA compliant placement. It demonstrates the feasibility of our approach through a simulation study, showing that we are capable of consistently obtaining good solutions in a time efficient manner. In addition, we discuss how resource utilization level can be improved through an advanced capacity management leveraging elastic workload resource consumption variability.

Networking is currently a field of innovation and massive changes driven by several factors, the most prominent of which is the shift to cloud computing. It is already widely understood that networking requirements of cloud computing infrastructures differ from anything that the established networking technologies can offer. We present Distributed Overlay Virtual nEtwork (DOVE), an architecture based on a novel network abstraction allowing to define provider-tenant contracts at application level. DOVE network abstraction is decoupled from the particulars of the physical infrastructure design. Still, it captures the network functionality that matters: connectivity, security, performance, etc. DOVE architecture allows cloud providers to consolidate multiple abstractly defined networks on large scale commodity physical infrastructures, utilizing the advantages of specialized hardware appliances, and delegating full control to their tenants that now can manage and administer their virtual networks.

Server virtualization has brought about tremendous value to a modern computing landscape and in particular to data center and cloud infrastructures. Virtual server deployments have become ubiquitous in many development and production sites, in cloud infrastructures and in disaster recovery solutions. Network connectivity is a vital aspect of modern computing. In this work we explore the new requirements the server virtualization brings to the networking world and show how these requirements are different from those of a physical server connectivity. We then describe the Distributed Overlay Virtual Ethernet (DOVE) network architecture for building virtual networks infrastructure. We show how host-based overlays answer the novel networking requirements and describe a working example of their usage for network virtualization. We discuss the benefits and the drawbacks of the method, outline options for its efficient implementation, and show what additional work is required in order to base DCN virtualization on overlays.

Current cloud infrastructures have opaque service offerings where customers cannot monitor the underlying physical infrastructure. This situation raises concerns for meeting compliance obligations by critical business applications with data location constraints that are deployed in a Cloud. When federated cloud infrastructures span across different countries where data can migrate from one country to another, it should be possible for data owners to monitor the location of their data. This paper shows how an existing federated Cloud monitoring infrastructure can be used for data location monitoring without compromising Cloud isolation. In the proposed approach collaboration is required between the cloud infrastructure provider (IP) and the user of the cloud, the service provider (SP): the IP monitors the virtual machines (VM) on the SP's behalf and makes the infrastructure level monitoring information available to him. With the monitoring information the SP can create the audit logs required for compliance auditing. The proposed logging architecture is validated by an e-Government case study with legal data location constraints.

As cloud computing becomes more predominant, the problem of scalability has become critical for cloud computing providers. The cloud paradigm is attractive because it offers a dramatic reduction in capital and operation expenses for consumers.