20,185 research outputs found
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A survey on online monitoring approaches of computer-based systems
This report surveys forms of online data collection that are in current use (as well as being the subject of research to adapt them to changing technology and demands), and can be used as inputs to assessment of dependability and resilience, although they are not primarily meant for this use
Detecting and Refactoring Operational Smells within the Domain Name System
The Domain Name System (DNS) is one of the most important components of the
Internet infrastructure. DNS relies on a delegation-based architecture, where
resolution of names to their IP addresses requires resolving the names of the
servers responsible for those names. The recursive structures of the inter
dependencies that exist between name servers associated with each zone are
called dependency graphs. System administrators' operational decisions have far
reaching effects on the DNSs qualities. They need to be soundly made to create
a balance between the availability, security and resilience of the system. We
utilize dependency graphs to identify, detect and catalogue operational bad
smells. Our method deals with smells on a high-level of abstraction using a
consistent taxonomy and reusable vocabulary, defined by a DNS Operational
Model. The method will be used to build a diagnostic advisory tool that will
detect configuration changes that might decrease the robustness or security
posture of domain names before they become into production.Comment: In Proceedings GaM 2015, arXiv:1504.0244
InterCloud: Utility-Oriented Federation of Cloud Computing Environments for Scaling of Application Services
Cloud computing providers have setup several data centers at different
geographical locations over the Internet in order to optimally serve needs of
their customers around the world. However, existing systems do not support
mechanisms and policies for dynamically coordinating load distribution among
different Cloud-based data centers in order to determine optimal location for
hosting application services to achieve reasonable QoS levels. Further, the
Cloud computing providers are unable to predict geographic distribution of
users consuming their services, hence the load coordination must happen
automatically, and distribution of services must change in response to changes
in the load. To counter this problem, we advocate creation of federated Cloud
computing environment (InterCloud) that facilitates just-in-time,
opportunistic, and scalable provisioning of application services, consistently
achieving QoS targets under variable workload, resource and network conditions.
The overall goal is to create a computing environment that supports dynamic
expansion or contraction of capabilities (VMs, services, storage, and database)
for handling sudden variations in service demands.
This paper presents vision, challenges, and architectural elements of
InterCloud for utility-oriented federation of Cloud computing environments. The
proposed InterCloud environment supports scaling of applications across
multiple vendor clouds. We have validated our approach by conducting a set of
rigorous performance evaluation study using the CloudSim toolkit. The results
demonstrate that federated Cloud computing model has immense potential as it
offers significant performance gains as regards to response time and cost
saving under dynamic workload scenarios.Comment: 20 pages, 4 figures, 3 tables, conference pape
Re-designing Dynamic Content Delivery in the Light of a Virtualized Infrastructure
We explore the opportunities and design options enabled by novel SDN and NFV
technologies, by re-designing a dynamic Content Delivery Network (CDN) service.
Our system, named MOSTO, provides performance levels comparable to that of a
regular CDN, but does not require the deployment of a large distributed
infrastructure. In the process of designing the system, we identify relevant
functions that could be integrated in the future Internet infrastructure. Such
functions greatly simplify the design and effectiveness of services such as
MOSTO. We demonstrate our system using a mixture of simulation, emulation,
testbed experiments and by realizing a proof-of-concept deployment in a
planet-wide commercial cloud system.Comment: Extended version of the paper accepted for publication in JSAC
special issue on Emerging Technologies in Software-Driven Communication -
November 201
A Case Study for Business Integration as a Service
This paper presents Business Integration as a Service (BIaaS) to allow two services to work together in the Cloud to achieve a streamline process. We illustrate this integration using two services; Return on Investment (ROI) Measurement as a Service (RMaaS) and Risk Analysis as a Service (RAaaS) in the case study at the University of Southampton. The case study demonstrates the cost-savings and the risk analysis achieved, so two services can work as a single service. Advanced techniques are used to demonstrate statistical services and 3D Visualisation services under the remit of RMaaS and Monte Carlo Simulation as a Service behind the design of RAaaS. Computational results are presented with their implications discussed. Different types of risks associated with Cloud adoption can be calculated easily, rapidly and accurately with the use of BIaaS. This case study confirms the benefits of BIaaS adoption, including cost reduction and improvements in efficiency and risk analysis. Implementation of BIaaS in other organisations is also discussed. Important data arising from the integration of RMaaS and RAaaS are useful for management and stakeholders of University of Southampton
Using Quantitative Methods as Support for Audit of the Distributed Informatics Systems
This paper highlights some issues regarding how an indicators system must be developed and used in an audit process. Distributed systems are presented from de points of view of their main properties, architectures, applications, software quality characteristics and the scope of audit process in such systems. The audit process is defined in accordance to standard ISO 19011 and the main characteristics of this process are highlighted. Before using quantitative methods in audit processes, the framework in which the indicators are built must be defined. There are presented types of indicators used in audit process and classes of measurement scale. An audit process is carried out on different levels and support indicators must be in accordance to audit object. The paper presents some requirements of the indicators depending on the level of audit.Quantitative Methods, Audit Process, Distributed Informatics System
Smart Asset Management for Electric Utilities: Big Data and Future
This paper discusses about future challenges in terms of big data and new
technologies. Utilities have been collecting data in large amounts but they are
hardly utilized because they are huge in amount and also there is uncertainty
associated with it. Condition monitoring of assets collects large amounts of
data during daily operations. The question arises "How to extract information
from large chunk of data?" The concept of "rich data and poor information" is
being challenged by big data analytics with advent of machine learning
techniques. Along with technological advancements like Internet of Things
(IoT), big data analytics will play an important role for electric utilities.
In this paper, challenges are answered by pathways and guidelines to make the
current asset management practices smarter for the future.Comment: 13 pages, 3 figures, Proceedings of 12th World Congress on
Engineering Asset Management (WCEAM) 201
An analysis of the adoption of OSS by local public administrations: Evidence from the Emilia-Romagna Region of Italy
The wide diffusion of open source software (OSS) is driving discussion among scholars on a set of issues, including its adoption by public administrations (PA). Previous works only discussed one or a few factors that drive the decision to adopt OSS and did not addressed the potential benefits in terms of e-government that OSS may bring to PA. Our paper attempts to fill these gaps. The analysis is based on the Emilia-Romagna region of Italy and studies the adoption of software (both proprietary and open source) by local PA. The results show there is increased adoption of OSS in several different domains of application, both servers and desktop clients. Among the motivations to adopt OSS, only dependence on software suppliers seems to be important. Its adoption also positively affects the variety and extent of interactivity of local public e-services.open source software; public administration; online public services; empirical research
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