No abstract

Virtual machine technology and the ease with which VMs can be migrated within the LAN, has changed the scope of resource management from allocating resources on a single server to manipulating pools of resources within a data center. We expect WAN migration of virtual machines to likewise transform the scope of provisioning compute resources from a single data center to multiple data centers spread across the country or around the world. In this paper we present the CloudNet architecure as a cloud framework consisting of cloud computing platforms linked with a VPN based network infrastructure to provide seamless and secure connectivity between enterprise and cloud data center sites. To realize our vision of efficiently pooling geographically distributed data center resources, CloudNet provides optimized support for live WAN migration of virtual machines. Specifically, we present a set of optimizations that minimize the cost of transferring storage and virtual machine memory during migrations over low bandwidth and high latency Internet links. We evaluate our system on an operational cloud platform distributed across the continental US. During simultaneous migrations of four VMs between data centers in Texas and Illinois, CloudNet's optimizations reduce memory migration time by 65% and lower bandwidth consumption for the storage and memory transfer by 19GB, a 50% reduction.

etworks have traditionally been composed of interconnected hardware such as routers, switches, and firewalls. Employing purposebuilt hardware appliances, managed through distributed protocols, has allowed networks to achieve high performance and reliability, but it comes at the cost of limited flexibility. This tradition has mostly continued, with such purpose-specific hardware systems being deployed even for typical software functions such as proxies, firewalls, and caches, because of the desire to have a high-performance data plane. This limits the flexibility of network functions, has high cost, and makes it difficult to deploy services dynamically.Cloud data centers have increased their efficiency and flexibility by employing virtualization techniques that allow convenient (often centralized) management of dynamically created server instances. With the adoption of software defined Nnetworking (SDN) and network function virtualization (NFV), a similar revolution is happening in both wide area networks and data center networks. SDN provides a logically centralized control plane that can flexibly direct packet flows between network devices based on programmable policies [1-3]. NFV transforms networks from hardware appliances with customized application-specific integrated circuits (ASICs) into software running in VMs (VMs) on common off-the-shelf (COTS) hardware to increase flexibility and lower cost [4-6]. Together, SDN and NFV offer the potential to radically alter how networks are deployed and managed.By moving to a software-based environment, NFV makes network services easy to deploy, and allows them to be more powerful and flexible, enabling more complex topologies and feature-rich network resident functions compared to hardware-based implementations. Unfortunately, the performance limitations of commodity hardware and the overhead of server virtualization platforms have prevented high-performance network processing to fully transition away from hardware-based routers and middleboxes. In this article we describe how a carefully designed NFV architecture can overcome these virtualization-layer overheads through zero-copy packet data transfer, non-uniform memory access (NUMA)-aware scheduling, and lockless data structures. Our approach exploits advances in multi-core CPUs and modern network interface cards (NICs) to enable a truly flexible, VM-based networking platform that can process packets at line rates.SDN has already impacted how networks are deployed and managed, but current approaches do not fully exploit the benefits of an NFV-based infrastructure. SDN controllers still assume they are interacting with simple hardware devices that are incapable of making decisions on their own. The reality is that increasing deployments of middleboxes and NFV-based services means that not only will flow management become more complex, but also that data plane elements will want to make dynamic decisions about how packets are directed. The ability to dynamically steer flows through selected service functions is a key ...

No abstract

The combination of Network Function Virtualization (NFV) and Software Defined Networking (SDN) allows flows to be flexibly steered through efficient processing pipelines. As deployment of NFV becomes more prevalent, the need to provide fine-grained customization of service chains and flowlevel performance guarantees will increase, even as the diversity of Network Functions (NFs) rises. Existing NFV approaches typically route wide classes of traffic through preconfigured service chains. While this aggregation improves efficiency, it prevents flexibly steering and managing performance of flows at a fine granularity. To provide both efficiency and flexibility, we present Flurries, an NFV platform designed to support large numbers of short-lived lightweight NFs, potentially running a unique NF for each flow. Flurries maintains a pool of Docker container NFs-several thousand on each host-and resets NF memory state between flows for fast reuse. Flurries uses a hybrid of polling and interrupts to improve throughput and latency while allowing multiple NFs to efficiently share CPU cores. By assigning each NF an individual flow or a small set of flows, it becomes possible to dynamically manage the QoS and service chain functionality for flows at a very fine granularity. Our Flurries prototype demonstrates the potential for this approach to run as many as 80,000 Flurry NFs during a one second interval, while forwarding over 30Gbps of traffic, dramatically increasing data plane customizability.