Tom Christian

SoftUDC: a software-based data center for utility computing

Utility computing aims to aggregate server, network, and storage systems into a single, centrally managed pool of resources. SoftUDC, a virtual machine monitor, lets applications and administrative domains share physical resources while maintaining full functional isolation.

1000 islands: an integrated approach to resource management for virtualized data centers

Recent advances in hardware and software virtualization offer unprecedented management capabilities for the mapping of virtual resources to physical resources. It is highly desirable to further create a “service hosting abstraction” that allows application owners to focus on service level objectives (SLOs) for their applications. This calls for a resource management solution that achieves the SLOs for many applications in response to changing data center conditions and hides the complexity from both application owners and data center operators. In this paper, we describe an automated capacity and workload management system that integrates multiple resource controllers at three different scopes and time scales. Simulation and experimental results confirm that such an integrated solution ensures efficient and effective use of data center resources while reducing service level violations for high priority applications.

Capacity planning and power management to exploit sustainable energy

This paper describes an approach for designing a power management plan that matches the supply of power with the demand for power in data centers. Power may come from the grid, from local renewable sources, and possibly from energy storage subsystems. The supply of renewable power is often time-varying in a manner that depends on the source that provides the power, the location of power generators, and the weather conditions. The demand for power is mainly determined by the time-varying workloads hosted in the data center and the power management policies implemented by the data center. A case study demonstrates how our approach can be used to design a plan for realistic and complex data center workloads. The study considers a data centers deployment in two geographic locations with different supplies of power. Our approach offers greater precision than other planning methods that do not take into account time-varying power supply and demand and data center power management policies.

Towards the design and operation of net-zero energy data centers

Reduction of resource consumption in data centers is becoming a growing concern for data center designers, operators and users. Accordingly, interest in the use of renewable energy to provide some portion of a data centers overall energy usage is also growing. One key concern is that the amount of renewable energy necessary to satisfy a typical data centers power consumption can lead to prohibitively high capital costs for the power generation and delivery infrastructure, particularly if on-site renewables are used. In this paper, we introduce a method to operate a data center with renewable energy that minimizes dependence on grid power while minimizing capital cost. We achieve this by integrating data center demand with the availability of resource supplies during operation. We discuss results from the deployment of our method in a production data center.

Profiling Sustainability of Data Centers

Todays data centers consume vast amounts of energy, leading to high operational costs, excessive water consumption, and significant greenhouse gas emissions. With the approach of micro grids, an opportunity exists to reduce the environmental impact and cost of power in data centers. To realize this, demand side power consumption needs to be understood and co-managed from the perspectives of both supply and demand. We present an approach to achieve this via data center power profiling and demonstrate its applicability for an enterprise data center.

Quantifying the sustainability impact of data center availability

Data center availability is critical considering the explosive growth in Internet services and peoples dependence on them. Furthermore, in recent years, sustainability has become important. However, data center designers have little information on the sustainability impact of data center availability architectures. In this paper, we present an approach to estimate the sustainability impact of such architectures. Availability is computed using Stochastic Petri Net (SPN) models while an exergy-based lifecycle assessment (LCA) approach is used for quantifying sustainability impact. The approach is demonstrated on real life data center power infrastructure architectures. Five different architectures are considered and initial results show that quantification of sustainability impact provides important information to a data center designer in evaluating availability architecture choices.

ASTRO: A tool for dependability evaluation of Data Center infrastructures

The advent of cloud computing has demanded more computational resources from data centers in order to provide high-availability services required in this new paradigm. To support data center dependability evaluation, this paper presents a tool, namely, ASTRO, which adopts a hybrid modeling approach, that includes Reliability Block Diagrams (RBD), Stochastic Petri Nets (SPN) and Data Center High-Level models. In addition, this tool also provides a prominent functionality in which an evaluation result can be reused in other models. ASTRO Tool also permits a hierarchical modeling, supporting the piecewise approach proposed by the methodology in which the tool is inserted.

Assessing ICT's Environmental Impact

Accurately quantifying information and communications technologys footprint is a critical first step toward reducing its environmental burden.

Water efficiency management in datacenters: Metrics and methodology

The demand for data center solutions with lower total cost of ownership and lower complexity of management is driving the creation of next generation datacenters. The information technology industry is in the midst of a transformation to lower the cost of operation through consolidation and better utilization of critical data center resources. Successful consolidation necessitates increasing utilization of capital intensive “always-on” data center infrastructure, reduction in the recurring cost of power and management of physical resources like water. A 1MW data center operating with water-cooled chillers and cooling towers can consume 18,000 gallons per day to dissipate heat generated by IT equipment. However, this water demand can be mitigated by appropriate use of air-cooled chillers or free cooling strategies that rely on local weather patterns. Water demand can also fluctuate with seasons and vary across geographies. Water efficiency, like energy efficiency is a key metric to evaluate sustainability of the IT ecosystem. In this paper, we propose a procedure for calculation of water efficiency of a datacenter and provide guidance for a management system that can optimize IT performance while managing the tradeoffs between water and energy efficiency in conventional datacenters.

Design of Farm Waste-Driven Supply Side Infrastructure for Data Centers

In this paper, we design a supply-side infrastructure for data centers that runs primarily on energy from digested farm waste. Although the information technology and livestock industries may seem completely disjoint, they have complementary characteristics that we exploit for mutual benefit. In particular, the farm waste fuels a combined heat and power system. The data center consumes the power, and its waste heat feeds back into the combined system. We propose a resource management system to manage the resource flows and effluents, and evaluate the direct and indirect economic benefits. As an example, we explain how a hypothetical farm of 10,000 dairy cows could fulfill the power requirements of a 1MW data center.