5,423 research outputs found
On the Verge of One Petabyte - the Story Behind the BaBar Database System
The BaBar database has pioneered the use of a commercial ODBMS within the HEP
community. The unique object-oriented architecture of Objectivity/DB has made
it possible to manage over 700 terabytes of production data generated since
May'99, making the BaBar database the world's largest known database. The
ongoing development includes new features, addressing the ever-increasing
luminosity of the detector as well as other changing physics requirements.
Significant efforts are focused on reducing space requirements and operational
costs. The paper discusses our experience with developing a large scale
database system, emphasizing universal aspects which may be applied to any
large scale system, independently of underlying technology used.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 6 pages. PSN MOKT01
Energy-aware Load Balancing Policies for the Cloud Ecosystem
The energy consumption of computer and communication systems does not scale
linearly with the workload. A system uses a significant amount of energy even
when idle or lightly loaded. A widely reported solution to resource management
in large data centers is to concentrate the load on a subset of servers and,
whenever possible, switch the rest of the servers to one of the possible sleep
states. We propose a reformulation of the traditional concept of load balancing
aiming to optimize the energy consumption of a large-scale system: {\it
distribute the workload evenly to the smallest set of servers operating at an
optimal energy level, while observing QoS constraints, such as the response
time.} Our model applies to clustered systems; the model also requires that the
demand for system resources to increase at a bounded rate in each reallocation
interval. In this paper we report the VM migration costs for application
scaling.Comment: 10 Page
Exact Solutions for M/M/c/Setup Queues
Recently multiserver queues with setup times have been extensively studied
because they have applications in power-saving data centers. The most
challenging model is the M/M//Setup queue where a server is turned off when
it is idle and is turned on if there are some waiting jobs. Recently, Gandhi et
al.~(SIGMETRICS 2013, QUESTA 2014) present the recursive renewal reward
approach as a new mathematical tool to analyze the model. In this paper, we
derive exact solutions for the same model using two alternative methodologies:
generating function approach and matrix analytic method. The former yields
several theoretical insights into the systems while the latter provides an
exact recursive algorithm to calculate the joint stationary distribution and
then some performance measures so as to give new application insights.Comment: Submitted for revie
Farm-level data integration: future problems and consequences for public and private structures
One of the outcomes of the EC-FP7 project “Future Farm” was showing the need of INTEGRATION, something that PROGIS has been doing for 15 years. Within the whole sector agriculture–forestry-environment-risk management there is an enormous need for integration that is not available yet, because of on side the existing admin-sector-structures plus on the other side diverse public and/or private interests with opposite directions and in many cases the not streamlined interest of ALL involved parties. On the other hand we have the nature that is fully integrated and should be managed by us! Nothing happens without being related to something else within the nature. We have to be more aware of this and have also to understand that ICT will be the driver of integration as data and based on it these information is necessary and urgently needed for public and for private structures. We can do it separately, doing things in parallel and multiple times with multiple costs and reduced results. The other option is to cooperate on an integrative model!Commons, farm management, valuation of land, ICT, Farm Management,
QuLa: service selection and forwarding table population in service-centric networking using real-life topologies
The amount of services located in the network has drastically increased over the last decade which is why more and more datacenters are located at the network edge, closer to the users. In the current Internet it is up to the client to select a destination using a resolution service (Domain Name System, Content Delivery Networks ...). In the last few years, research on Information-Centric Networking (ICN) suggests to put this selection responsibility at the network components; routers find the closest copy of a content object using the content name as input.
We extend the principle of ICN to services; service routers forward requests to service instances located in datacenters spread across the network edge. To solve this problem, we first present a service selection algorithm based on both server and network metrics. Next, we describe a method to reduce the state required in service routers while minimizing the performance loss caused by this data reduction. Simulation results based on real-life networks show that we are able to find a near-optimal load distribution with only minimal state required in the service routers
The Clarens Web Service Framework for Distributed Scientific Analysis in Grid Projects
Large scientific collaborations are moving towards service oriented architecutres for implementation and deployment of globally distributed systems. Clarens is a high performance, easy to deploy Web Service framework that supports the construction of such globally distributed systems. This paper discusses some of the core functionality of Clarens that the authors believe is important for building distributed systems based on Web Services that support scientific analysis
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