520,885 research outputs found
C2MS: Dynamic Monitoring and Management of Cloud Infrastructures
Server clustering is a common design principle employed by many organisations
who require high availability, scalability and easier management of their
infrastructure. Servers are typically clustered according to the service they
provide whether it be the application(s) installed, the role of the server or
server accessibility for example. In order to optimize performance, manage load
and maintain availability, servers may migrate from one cluster group to
another making it difficult for server monitoring tools to continuously monitor
these dynamically changing groups. Server monitoring tools are usually
statically configured and with any change of group membership requires manual
reconfiguration; an unreasonable task to undertake on large-scale cloud
infrastructures.
In this paper we present the Cloudlet Control and Management System (C2MS); a
system for monitoring and controlling dynamic groups of physical or virtual
servers within cloud infrastructures. The C2MS extends Ganglia - an open source
scalable system performance monitoring tool - by allowing system administrators
to define, monitor and modify server groups without the need for server
reconfiguration. In turn administrators can easily monitor group and individual
server metrics on large-scale dynamic cloud infrastructures where roles of
servers may change frequently. Furthermore, we complement group monitoring with
a control element allowing administrator-specified actions to be performed over
servers within service groups as well as introduce further customized
monitoring metrics. This paper outlines the design, implementation and
evaluation of the C2MS.Comment: Proceedings of the The 5th IEEE International Conference on Cloud
Computing Technology and Science (CloudCom 2013), 8 page
A Change Support Model for Distributed Collaborative Work
Distributed collaborative software development tends to make artifacts and
decisions inconsistent and uncertain. We try to solve this problem by providing
an information repository to reflect the state of works precisely, by managing
the states of artifacts/products made through collaborative work, and the
states of decisions made through communications. In this paper, we propose
models and a tool to construct the artifact-related part of the information
repository, and explain the way to use the repository to resolve
inconsistencies caused by concurrent changes of artifacts. We first show the
model and the tool to generate the dependency relationships among UML model
elements as content of the information repository. Next, we present the model
and the method to generate change support workflows from the information
repository. These workflows give us the way to efficiently modify the
change-related artifacts for each change request. Finally, we define
inconsistency patterns that enable us to be aware of the possibility of
inconsistency occurrences. By combining this mechanism with version control
systems, we can make changes safely. Our models and tool are useful in the
maintenance phase to perform changes safely and efficiently.Comment: 10 pages, 13 figures, 4 table
Source File Set Search for Clone-and-Own Reuse Analysis
Clone-and-own approach is a natural way of source code reuse for software
developers. To assess how known bugs and security vulnerabilities of a cloned
component affect an application, developers and security analysts need to
identify an original version of the component and understand how the cloned
component is different from the original one. Although developers may record
the original version information in a version control system and/or directory
names, such information is often either unavailable or incomplete. In this
research, we propose a code search method that takes as input a set of source
files and extracts all the components including similar files from a software
ecosystem (i.e., a collection of existing versions of software packages). Our
method employs an efficient file similarity computation using b-bit minwise
hashing technique. We use an aggregated file similarity for ranking components.
To evaluate the effectiveness of this tool, we analyzed 75 cloned components in
Firefox and Android source code. The tool took about two hours to report the
original components from 10 million files in Debian GNU/Linux packages. Recall
of the top-five components in the extracted lists is 0.907, while recall of a
baseline using SHA-1 file hash is 0.773, according to the ground truth recorded
in the source code repositories.Comment: 14th International Conference on Mining Software Repositorie
Collaborative support for distributed design
A number of large integrated projects have been funded by the European Commission within both FP5 and FP6 that have aimed to develop distributed design solutions within the shipbuilding industry. VRShips-ROPAX was funded within FP5 and aimed to develop a platform to support distributed through-life design of a ROPAX (roll-on passenger) ferry. VIRTUE is an FP6 funded project that aims to integrate distributed virtual basins within a platform that allows a holistic Computational Fluid Dynamics (CFD) analysis of a ship to be undertaken. Finally, SAFEDOR is also an FP6 funded project that allows designers to perform distributed Risk-Based Design (RBD) and simulation of different types of vessels. The projects have a number of commonalities: the designers are either organisationally or geographically distributed; a large amount of the design and analysis work requires the use of computers, and the designers are expected to collaborate - sharing design tasks and data. In each case a Virtual Integration Platform (VIP) has been developed, building on and sharing ideas between the projects with the aim of providing collaborative support for distributed design. In each of these projects the University of Strathclyde has been primarily responsible for the development of the associated VIP. This paper describes each project in terms of their differing collaborative support requirements, and discusses the associated VIP in terms of the manner that collaborative support has been provided
Simulation System for the Wendelstein 7-X Safety Control System
The Wendelstein 7-X (W7-X) Safety Instrumented System (SIS) ensures personal
safety and investment protection. The development and implementation of the SIS
are based on the international safety standard for the process industry sector,
IEC 61511. The SIS exhibits a distributed and hierarchical organized
architecture consisting of a central Safety System (cSS) on the top and many
local Safety Systems (lSS) at the bottom. Each technical component or
diagnostic system potentially hazardous for the staff or for the device is
equipped with an lSS. The cSS is part of the central control system of W7-X.
Whereas the lSSs are responsible for the safety of each individual component,
the cSS ensures safety of the whole W7-X device. For every operation phase of
the W7-X experiment hard- and software updates for the SIS are mandatory. New
components with additional lSS functionality and additional safety signals have
to be integrated. Already established safety functions must be adapted and new
safety functions have to be integrated into the cSS. Finally, the safety
programs of the central and local safety systems have to be verified for every
development stage and validated against the safety requirement specification.
This contribution focuses on the application of a model based simulation system
for the whole SIS of W7-X. A brief introduction into the development process of
the SIS and its technical realization will be give followed by a description of
the design and implementation of the SIS simulation system using the framework
SIMIT (Siemens). Finally, first application experiences of this simulation
system for the preparation of the SIS for the upcoming operation phase OP 1.2b
of W7-X will be discussed
Beyond Reuse Distance Analysis: Dynamic Analysis for Characterization of Data Locality Potential
Emerging computer architectures will feature drastically decreased flops/byte
(ratio of peak processing rate to memory bandwidth) as highlighted by recent
studies on Exascale architectural trends. Further, flops are getting cheaper
while the energy cost of data movement is increasingly dominant. The
understanding and characterization of data locality properties of computations
is critical in order to guide efforts to enhance data locality. Reuse distance
analysis of memory address traces is a valuable tool to perform data locality
characterization of programs. A single reuse distance analysis can be used to
estimate the number of cache misses in a fully associative LRU cache of any
size, thereby providing estimates on the minimum bandwidth requirements at
different levels of the memory hierarchy to avoid being bandwidth bound.
However, such an analysis only holds for the particular execution order that
produced the trace. It cannot estimate potential improvement in data locality
through dependence preserving transformations that change the execution
schedule of the operations in the computation. In this article, we develop a
novel dynamic analysis approach to characterize the inherent locality
properties of a computation and thereby assess the potential for data locality
enhancement via dependence preserving transformations. The execution trace of a
code is analyzed to extract a computational directed acyclic graph (CDAG) of
the data dependences. The CDAG is then partitioned into convex subsets, and the
convex partitioning is used to reorder the operations in the execution trace to
enhance data locality. The approach enables us to go beyond reuse distance
analysis of a single specific order of execution of the operations of a
computation in characterization of its data locality properties. It can serve a
valuable role in identifying promising code regions for manual transformation,
as well as assessing the effectiveness of compiler transformations for data
locality enhancement. We demonstrate the effectiveness of the approach using a
number of benchmarks, including case studies where the potential shown by the
analysis is exploited to achieve lower data movement costs and better
performance.Comment: Transaction on Architecture and Code Optimization (2014
Virtue integrated platform : holistic support for distributed ship hydrodynamic design
Ship hydrodynamic design today is often still done in a sequential approach. Tools used for the different aspects of CFD (Computational Fluid Dynamics) simulation (e.g. wave resistance, cavitation, seakeeping, and manoeuvring), and even for the different levels of detail within a single aspect, are often poorly integrated. VIRTUE (the VIRtual Tank Utility in Europe) project has the objective to develop a platform that will enable various distributed CFD and design applications to be integrated so that they may operate in a unified and holistic manner. This paper presents an overview of the VIRTUE Integrated Platform (VIP), e.g. research background, objectives, current work, user requirements, system architecture, its implementation, evaluation, and current development and future work
An artefact repository to support distributed software engineering
The Open Source Component Artefact Repository (OSCAR)
system is a component of the GENESIS platform designed to
non-invasively inter-operate with work-flow management systems, development tools and existing repository systems to support a distributed software engineering team working collaboratively. Every artefact possesses a collection of associated meta-data, both standard and domain-specific presented as an XML document. Within OSCAR, artefacts are made aware of changes to related artefacts using notifications, allowing them to modify their own meta-data actively in contrast to other software repositories where users must perform all and any modifications, however trivial.
This recording of events, including user interactions provides a complete picture of an artefact's life from creation to (eventual) retirement with the intention of supporting collaboration both amongst the members of the software engineering team and agents acting on their behalf
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