4,922 research outputs found
GEAMS: a Greedy Energy-Aware Multipath Stream-based Routing Protocol for WMSNs
Because sensor nodes operate on power limited batteries, sensor
functionalities have to be designed carefully. In particular, designing
energy-efficient packet forwarding is important to maximize the lifetime of the
network and to minimize the power usage at each node. This paper presents a
Geographic Energy-Aware Multipath Stream-based (GEAMS) routing protocol for
WMSNs. GEAMS routing decisions are made online, at each forwarding node in such
a way that there is no need to global topology knowledge and maintenance. GEAMS
routing protocol performs load-balancing to minimize energy consumption among
nodes using twofold policy: (1) smart greedy forwarding and (2) walking back
forwarding. Performances evaluations of GEAMS show that it can maximize the
network lifetime and guarantee quality of service for video stream transmission
in WMSNs
Split and Migrate: Resource-Driven Placement and Discovery of Microservices at the Edge
Microservices architectures combine the use of fine-grained and independently-scalable services with lightweight communication protocols, such as REST calls over HTTP. Microservices bring flexibility to the development and deployment of application back-ends in the cloud.
Applications such as collaborative editing tools require frequent interactions between the front-end running on users\u27 machines and a back-end formed of multiple microservices. User-perceived latencies depend on their connection to microservices, but also on the interaction patterns between these services and their databases. Placing services at the edge of the network, closer to the users, is necessary to reduce user-perceived latencies. It is however difficult to decide on the placement of complete stateful microservices at one specific core or edge location without trading between a latency reduction for some users and a latency increase for the others.
We present how to dynamically deploy microservices on a combination of core and edge resources to systematically reduce user-perceived latencies. Our approach enables the split of stateful microservices, and the placement of the resulting splits on appropriate core and edge sites. Koala, a decentralized and resource-driven service discovery middleware, enables REST calls to reach and use the appropriate split, with only minimal changes to a legacy microservices application. Locality awareness using network coordinates further enables to automatically migrate services split and follow the location of the users. We confirm the effectiveness of our approach with a full prototype and an application to ShareLatex, a microservices-based collaborative editing application
DALiuGE: A Graph Execution Framework for Harnessing the Astronomical Data Deluge
The Data Activated Liu Graph Engine - DALiuGE - is an execution framework for
processing large astronomical datasets at a scale required by the Square
Kilometre Array Phase 1 (SKA1). It includes an interface for expressing complex
data reduction pipelines consisting of both data sets and algorithmic
components and an implementation run-time to execute such pipelines on
distributed resources. By mapping the logical view of a pipeline to its
physical realisation, DALiuGE separates the concerns of multiple stakeholders,
allowing them to collectively optimise large-scale data processing solutions in
a coherent manner. The execution in DALiuGE is data-activated, where each
individual data item autonomously triggers the processing on itself. Such
decentralisation also makes the execution framework very scalable and flexible,
supporting pipeline sizes ranging from less than ten tasks running on a laptop
to tens of millions of concurrent tasks on the second fastest supercomputer in
the world. DALiuGE has been used in production for reducing interferometry data
sets from the Karl E. Jansky Very Large Array and the Mingantu Ultrawide
Spectral Radioheliograph; and is being developed as the execution framework
prototype for the Science Data Processor (SDP) consortium of the Square
Kilometre Array (SKA) telescope. This paper presents a technical overview of
DALiuGE and discusses case studies from the CHILES and MUSER projects that use
DALiuGE to execute production pipelines. In a companion paper, we provide
in-depth analysis of DALiuGE's scalability to very large numbers of tasks on
two supercomputing facilities.Comment: 31 pages, 12 figures, currently under review by Astronomy and
Computin
Using Process Mining and Model-driven Engineering to Enhance Security of Web Information Systems
Due to the development of Smart Cities and Internet of Things, there has been an increasing interest in the use of Web information systems in different areas and domains. Besides, the number of attacks received by this kind of systems is increasing continuously. Therefore, there is a need to strengthen their protection and security. In this paper, we propose a method based on Process Mining and Model- Driven Engineering to improve the security of Web information systems. Besides, this method has been applied to the SID Digital Library case study and some preliminary results to improve the security of this system are described
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