Timothy Wood

George Washington University | GW · Department of Computer Science

Many emerging novel applications expect "near real-time" process- ing and responses, which can not be guaranteed by today’s Cloud and would require processing at the Edge. Serverless computing is a particularly promising architecture for edge environments since it offers to improve efficiency by precisely scaling resources to meet application needs...

Ensuring high availability (HA) for software-based networks is a critical design feature that will help the adoption of software-based network functions (NFs) in production networks. It is important for NFs to avoid outages and maintain mission-critical operations. However, HA support for NFs on the critical data path can result in unacceptable per...

Managing Network Function (NF) service chains requires careful system resource management. We propose NFVnice, a user space NF scheduling and service chain management framework to provide fair, efficient and dynamic resource scheduling capabilities on Network Function Virtualization (NFV) platforms. The NFVnice framework monitors load on a service...

In the future, computing will be immersed in the world around us -- from augmented reality to autonomous vehicles to the Internet of Things. Many of these smart devices will offer services that respond in real time to their physical surroundings, requiring complex processing with strict performance guarantees. Edge clouds promise a pervasive comput...

Ensuring high availability (HA) for software-based networks is a critical design feature that will help the adoption of software-based network functions (NFs) in production networks. It is important for NFs to avoid outages and maintain mission-critical operations. However, HA support for NFs on the critical data path can result in unacceptable per...

Existing network service chaining frameworks are based on a "packet-centric" model where each NF in a chain is given every packet for processing. This approach becomes both inefficient and inconvenient for more complex network functions that operate at higher levels of the protocol stack. We propose Microboxes, a novel service chaining abstraction...

Existing software dataplanes that run network functions inside VMs or containers can provide either performance (by dedicating CPU cores) or multiplexing (by context switching), but not both at once. Function-based dataplane architectures by replacing VMs and containers with function calls promise to achieve multiplexing and performance at the same...

Software-based network functions (NFs) have seen growing interest. Increasingly complex functionality is achieved by having multiple functions chained together to support the required network-resident services. Network Function Virtualization (NFV) platforms need to scale and achieve high performance, potentially utilizing multiple hosts in a clust...

Managing Network Function (NF) service chains requires careful system resource management. We propose NFVnice, a user space NF scheduling and service chain management framework to provide fair, efficient and dynamic resource scheduling capabilities on Network Function Virtualization (NFV) platforms. The NFVnice framework monitors load on a service...

Software Defined Networking (SDN) promises greater flexibility for directing packet flows, and Network Function Virtualization promises to enable dynamic management of software-based network functions. However, the current divide between an intelligent control plane and an overly simple, stateless data plane results in the inability to exploit the...

Application performance monitoring in large data centers relies on either deploying expensive and specialized hardware at fixed locations or heavily customizing applications and collecting logs spread across thousands of servers. Such an endeavor makes performance diagnosis a time-consuming task for cloud providers and a problem beyond the control...

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 flow-level performance guarantees will increase, even as the dive...

Network middleboxes are growing in number and diversity. Middleboxes have been deployed widely to complement the basic end-to-end functionality provided by the Internet Protocol suite that depends only on the minimal functionality of a best-effort network layer. The move from purpose-built hardware middleboxes to software appliances running in virt...

Software Defined Networking (SDN) promises greater flexibility for directing packet flows, and Network Function Virtualization promises to enable dynamic management of software-based network functions. However, the current divide between an intelligent control plane and an overly simple, stateless data plane results in the inability to exploit the...

Network Function Virtualization (NFV) promises to fundamentally change how we think of networks-changing them from pipes that transport data to processing pipelines that can efficiently transform that data as it moves between end points. This demo will present OpenNetVM, a highly efficient packet processing framework that greatly simplifies the dev...

Networks increasingly incorporate complex functionality, going beyond simple forwarding. Packet flows require processing through a complex set of services, that may often be provided in the cloud or on commercial off the shelf (COTS) hardware. This paper investigates the problem of scheduling network functions in different service chains, on a sing...

Network Function Virtualization promises to enable dynamic management of software-based network functions. We envision a dynamic and flexible network that can support a smarter data plane than just simple switches that forward packets. This network architecture supports complex stateful rourtng of flows where processing by network functions (NFs) c...

Multi-tier data-intensive applications are widely deployed in virtualized data centers for high scalability and reliability. As the response time is vital for user satisfaction, this requires achieving good performance at each tier of the applications in order to minimize the overall latency. However, in such virtualized environments, each tier (e....

The use of Network Function Virtualization to run network services in software enables Software Defined Networks to create a largely software-based network. We envision a dynamic and flexible network that can support a smarter data plane than just simple switches that forward packets. This network architecture needs to support complex stateful rout...

Virtualization technology and the ease with which virtual machines (VMs) can be migrated within the LAN have 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 resour...

Virtualization promised to dramatically increase server utilization levels, yet many data centers are still only lightly loaded. In some ways, big data applications are an ideal fit for using this residual capacity to perform meaningful work, but the high level of interference between interactive and batch processing workloads currently prevents th...

Communication networks are changing. They are becoming more and more ???software- based.??? Two trends reflect this: the use of software defined networking and the use of virtualization to exploit common off-the-shelf hardware to provide a wide array of network-resident functions. To truly achieve the vision shared by many service providers of a hi...

The integration of network function virtualization (NFV) and software defined networks (SDN) seeks to create a more flexible and dynamic software-based network environment. The line between entities involved in forwarding and those involved in more complex middle box functionality in the network is blurred by the use of high-performance virtualized...

NetVM brings virtualization to the Network by enabling high bandwidth network functions to operate at near line speed, while taking advantage of the flexibility and customization of low cost commodity servers. NetVM allows customizable data plane processing capabilities such as firewalls, proxies, and routers to be embedded within virtual machines,...

In cloud data centers, more and more services are deployed across multiple tiers to increase flexibility and scalability. However, this makes it difficult for the cloud provider to identify which tier of the application is the bottleneck and how to resolve performance problems. Existing solutions approach this problem by constantly monitoring eithe...

Methods and apparatus to migrate virtual machines between distributive computing networks across a network are disclosed. A disclosed example method includes establishing a data link across a network between a first distributive computing network and a second distributive computing network, the first distributive computing network including a virtu...

Data center servers are typically overprovisioned, leaving spare memory and CPU capacity idle to handle unpredictable workload bursts by the virtual machines running on them [1, 2, 3]. While this allows for fast hotspot mitigation, it is also wasteful. Unfortunately, making use of spare capacity without impacting active applications is particularly...

Cloud data centers are difficult to manage because providers have no knowledge of what applications are being run by customers or how they interact. As a consequence, current clouds provide minimal automated management functionality, passing the problem on to users who have access to even fewer tools since they lack insight into the underlying infr...

Application and OS-level caches are crucial for hiding I/O latency and improving application performance. However, caches are designed to greedily consume memory, which can cause memory-hogging problems in a virtualized data centers since the hypervisor cannot tell for what a virtual machine uses its memory. A group of virtual machines may contain...

A revolution is beginning in communication networks with the adoption of network function virtualization, which allows network services to be run on common off-the-shelf hardware—even in virtual machines—to increase flexibility and lower cost. An exciting prospect for cloud users is that these software-based network services can be merged with comp...

Web services, large and small, use in-memory caches like memcached to lower database loads and quickly respond to user requests. These cache clusters are typically provisioned to support peak load, both in terms of request processing capabilities and cache storage size. This kind of worst-case provisioning can be very expensive (e.g., Facebook repo...

The success of cloud computing builds largely upon on-demand supply of virtual machines (VMs) that provide the abstraction of a physical machine on shared resources. Unfortunately, despite recent advances in virtu-alization technology, there still exists an unpredictable performance gap between the real and desired performance. The main contributin...

Virtualization promised to dramatically increase server utilization levels, yet many data centers are still only lightly loaded. In some ways, big data applications are an ideal fit for using this residual capacity to perform meaningful work, but the high level of interference between interactive and batch processing workloads currently prevents th...

The high cost of provisioning resources to meet peak application demands has led to the widespread adoption of pay-as-you-go cloud computing services to handle workload fluctuations. Some enterprises with existing IT infrastructure employ a hybrid cloud model where the enterprise uses its own private resources for the majority of its computing, but...

NetVM brings virtualization to the Network by enabling high bandwidth network functions to operate at near line speed, while taking advantage of the flexibility and customization of low cost commodity servers. NetVM allows customizable data plane processing capabilities such as firewalls, proxies, and routers to be embedded within virtual machines,...

Data center servers are typically overprovisioned, leaving spare memory and CPU capacity idle to handle unpredictable workload bursts by the virtual machines running on them. While this allows for fast hotspot mitigation, it is also wasteful. Unfortunately, making use of spare capacity without impacting active applications is particularly difficult...

Virtualized environments are attractive because they simplify cluster management, while facilitating cost-effective workload consolidation. As a result, virtual machines in public clouds or private data centers, have become the norm for running transactional applications like web services and virtual desktops. On the other hand, batch workloads lik...

This paper presents a novel approach to improve firewall performance using data mining techniques. A traditional packet filtering firewall compares a packet against each filtering rule until a match is found. The filtering rules are stored as a rule list. Therefore, the time required to process a packet depends linearly on the number of filtering r...

Virtualization has become a popular way to make more efficient use of server resources within both private data centers and public cloud platforms. While recent advances in CPU architectures and new virtualization techniques have reduced the performance cost of using virtualization, overheads still exist, particularly when multiple virtual machines...

Today's businesses have a wealth of options available to them for running their applications. They can use proprietary infrastructures, private data centers, co-location facilities, or public clouds. Applications can be deployed on native hardware or virtualization can be used to improve consolidation and manageability. Public cloud platforms are g...

Cloud computing platforms such as Amazon EC2 provide customers with flexible, on-demand resources at low cost. However, while existing offerings are useful for providing basic computation and storage resources, they have not provided the transparency, security and network controls that many enterprise customers would like. While cloud computing has...

Virtual Desktop Infrastructures (VDIs) are gaining popularity in cloud computing by allowing companies to deploy their office environments in a virtualized setting instead of relying on physical desktop machines. Consolidating many users into a VDI environment can significantly lower IT management expenses and enables new features such as "availabl...

Enterprises with existing IT infrastructure are beginning to employ a hybrid cloud model where the enterprise uses its own private resources for the majority of its computing, but then "bursts" into the cloud when local resources are insufficient. However, current approaches to cloud bursting cannot be effectively automated because they heavily rel...

Content-based page sharing is a technique often used in virtualized environments to reduce server memory requirements. Many systems have been proposed to capture the benefits of page sharing. However, there have been few analyses of page sharing in general, both considering its real-world utility and typical sources of sharing potential. We provide...

The rising complexity of distributed server applications in Internet data centers has made the tasks of modeling and analyzing their behavior increasingly difficult. This article presents Modellus, a novel system for automated modeling of complex web-based data center applications using methods from queuing theory, data mining, and machine learning...

Disaster Recovery (DR) is a desirable feature for all enterprises, and a crucial one for many. However, adoption of DR remains limited due to the stark tradeoffs it imposes. To recover an application to the point of crash, one is limited by financial considerations, substantial application overhead, or minimal geographical separation between the pr...

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...

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...

Web applications have evolved from serving static content to dynamically generating Web pages. Web 2.0 applications include JavaScript and AJAX technologies that manage increasingly complex interactions between the client and the Web server. Traditional benchmarks rely on browser emulators that mimic the basic network functionality of real Web brow...

The high replication cost of Byzantine fault-tolerance (BFT) methods has been a major barrier to their widespread adoption in commercial distributed applications. We present ZZ, a new approach that reduces the replication cost of BFT services from 2f+1 to practically f+1. The key insight in ZZ is to use f+1 execution replicas in the normal case and...

Cloud computing platforms are growing from clusters of machines within a data center to networks of data centers with resources spread across the globe. Virtual machine migration within the LAN has changed the scale of resource management from allocating re-sources on a single server to manipulating pools of resources within a data center. We expec...

Many businesses rely on Disaster Recovery (DR) services to prevent either manmade or natural disasters from causing expensive service disruptions. Unfortunately, current DR services come either at very high cost, or with only weak guarantees about the amount of data lost or time required to restart operation after a failure. In this work, we argue...

Virtualization can provide significant benefits in data centers by enabling dynamic virtual machine resizing and migration to eliminate hotspots. We present Sandpiper, a system that automates the task of monitoring and detecting hotspots, determining a new mapping of physical to virtual resources, resizing virtual machines to their new allocations,...

Many data center virtualization solutions, such as VMware ESX, employ content-based page sharing to consolidate the resources of multiple servers. Page sharing identifies virtual machine memory pages with identical content and consolidates them into a single shared page. This technique, implemented at the host level, applies only between VMs placed...

Many data center virtualization solutions, such as VMware ESX, employ content-based page sharing to consolidate the resources of multiple servers. Page sharing identifies virtual machine memory pages with identical content and consolidates them into a single shared page. This technique, implemented at the host level, applies only between VMs placed...

Many data center virtualization solutions, such as VMware ESX, employ content-based page sharing to consolidate the resources of multiple servers. Page sharing identifies virtual machine memory pages with identical content and consolidates them into a single shared page. This technique, implemented at the host level, applies only between VMs placed...

Dynamic capacity provisioning is a useful technique for handling the multi-time-scale variations seen in Internet workloads. In this article, we propose a novel dynamic provisioning technique for multi-tier Internet applications that employs (1) a flexible queuing model to determine how much of the resources to allocate to each tier of the applicat...

Next Generation Data Centers are transforming labor-inten- sive, hard-coded systems into shared, virtualized, automated, and fully managed adaptive infrastructures. Virtualization technologies promise great opportunities for reducing energy and hardware costs through server consolidation. However, to safely transition an application running nativel...

HP Laboratories HPL-2008-122 virtualization, application resource usage, benchmarking, modeling, automation, performance models, regression-based approach Next Generation Data Centers (NGDC) are transforming labor-intensive, hard-coded, siloed systems into shared, virtualized, automated, and fully managed adaptive infrastructures. Virtualization te...

Virtualization can provide significant benefits in data centers by enabling virtual machine migration to eliminate hotspots. We present Sandpiper, a system that automates the task of mon- itoring and detecting hotspots, determining a new mapping of physical to virtual resources and initiating the necessary mi- grations. Sandpiper implements a black...