1,255 research outputs found
Designing Monitoring Systems for Continuous Certification of Cloud Services: Deriving Meta-requirements and Design Guidelines
Continuous service certification (CSC) involves the consistently gathering and assessing certification-relevant information about cloud service operations to validate whether they continue to adhere to certification criteria. Previous research has proposed test-based CSC methodologies that directly assess the components of cloud service infrastructures. However, test-based certification requires that certification authorities can access the cloud infrastructure, which various issues may limit. To address these challenges, cloud service providers need to conduct monitoring-based CSC; that is, monitor their cloud service infrastructure to gather certification-relevant data by themselves and then provide these data to certification authorities. Nevertheless, we need to better understand how to design monitoring systems to enable cloud service providers to perform such monitoring. By taking a design science perspective, we derive universal meta-requirements and design guidelines for CSC monitoring systems based on findings from five expert focus group interviews with 33 cloud experts and 10 one-to-one interviews with cloud customers. With this study, we expand the current knowledge base regarding CSC and monitoring-based CSC. Our derived design guidelines contribute to the development of CSC monitoring systems and enable monitoring-based CSC that overcomes issues of prior test-based approaches
From Facility to Application Sensor Data: Modular, Continuous and Holistic Monitoring with DCDB
Today's HPC installations are highly-complex systems, and their complexity
will only increase as we move to exascale and beyond. At each layer, from
facilities to systems, from runtimes to applications, a wide range of tuning
decisions must be made in order to achieve efficient operation. This, however,
requires systematic and continuous monitoring of system and user data. While
many insular solutions exist, a system for holistic and facility-wide
monitoring is still lacking in the current HPC ecosystem. In this paper we
introduce DCDB, a comprehensive monitoring system capable of integrating data
from all system levels. It is designed as a modular and highly-scalable
framework based on a plugin infrastructure. All monitored data is aggregated at
a distributed noSQL data store for analysis and cross-system correlation. We
demonstrate the performance and scalability of DCDB, and describe two use cases
in the area of energy management and characterization.Comment: Accepted at the The International Conference for High Performance
Computing, Networking, Storage, and Analysis (SC) 201
Executable formal specifications of complex distributed systems with CoreASM
Formal specifications play a crucial role in the design of reliable complex software systems. Executable formal specifications allow the designer to attain early validation and verification of design using static analysis techniques and accurate simulation of the runtime behavior of the system-to-be. With increasing complexity of software-intensive computer-based systems and the challenges of validation and verification of abstract software models prior to coding, the need for interactive software tools supporting executable formal specifications is even more evident. In this paper, we discuss how CoreASM, an environment for writing and running executable specifications according to the ASM method, provides flexibility and manages the complexity by using an innovative extensible language architecture
Orchestrator conversation : distributed management of cloud applications
Managing cloud applications is complex, and the current state of the art is not addressing this issue. The ever-growing software ecosystem continues to increase the knowledge required to manage cloud applications at a time when there is already an IT skills shortage. Solving this issue requires capturing IT operation knowledge in software so that this knowledge can be reused by system administrators who do not have it. The presented research tackles this issue by introducing a new and fundamentally different way to approach cloud application management: a hierarchical collection of independent software agents, collectively managing the cloud application. Each agent encapsulates knowledge of how to manage specific parts of the cloud application, is driven by sending and receiving cloud models, and collaborates with other agents by communicating using conversations. The entirety of communication and collaboration in this collection is called the orchestrator conversation. A thorough evaluation shows the orchestrator conversation makes it possible to encapsulate IT operations knowledge that current solutions cannot, reduces the complexity of managing a cloud application, and happens inherently concurrent. The evaluation also shows that the conversation figures out how to deploy a single big data cluster in less than 100 milliseconds, which scales linearly to less than 10 seconds for 100 clusters, resulting in a minimal overhead compared with the deployment time of at least 20 minutes with the state of the art
Towards engineering ontologies for cognitive profiling of agents on the semantic web
Research shows that most agent-based collaborations
suffer from lack of flexibility. This is due to the fact that
most agent-based applications assume pre-defined
knowledge of agents’ capabilities and/or neglect basic
cognitive and interactional requirements in multi-agent
collaboration. The highlight of this paper is that it brings
cognitive models (inspired from cognitive sciences and HCI)
proposing architectural and knowledge-based requirements
for agents to structure ontological models for cognitive
profiling in order to increase cognitive awareness between
themselves, which in turn promotes flexibility, reusability
and predictability of agent behavior; thus contributing
towards minimizing cognitive overload incurred on humans.
The semantic web is used as an action mediating space,
where shared knowledge base in the form of ontological
models provides affordances for improving cognitive
awareness
A unified approach to the development and usage of mobile agents
Mobile agents are an interesting approach to the development of distributed systems. By moving freely accross the network, they allow for the distribution of computation as well as gathering and filtering of information in an autonomous way. Over the last decade, the agent research community has decidedly achieved tremendous results.
However, the community was not able to provide easy to use toolkits to make this paradigm available to a broader audience. By embracing simplicity during the creation of a formal model and a reference implementation to create and execute instances of that model, our aim is to enable a wide audience – even non-experts – to create, adapt and use mobile agents. The proposed model allows for the creation of agents by combining atomic, self-contained building blocks and we provide an approachable, easy to use graphical editor for the creation
of model instances. In two evaluations, we could reinforce our believes that, with the achieved results, we could reach our aims
Méta-modélisation de l'adaptation dynamique du contrôle des systèmes multi-agents
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal
Simulating social relations in multi-agent systems
Open distributed systems are comprised of a large number of heterogeneous nodes with disparate requirements and objectives, a number of which may not conform to the system specification. This thesis argues that activity in such systems can be regulated by using distributed mechanisms inspired by social science theories regarding similarity /kinship, trust, reputation, recommendation and economics. This makes it possible to create scalable and robust agent societies which can adapt to overcome structural impediments and provide inherent defence against malicious and incompetent action, without detriment to system functionality and performance.
In particular this thesis describes:
• an agent based simulation and animation platform (PreSage), which offers the agent developer and society designer a suite of powerful tools for creating, simulating and visualising agent societies from both a local and global perspective.
• a social information dissemination system (SID) based on principles of self organisation which personalises recommendation and directs information dissemination.
• a computational socio-cognitive and economic framework (CScEF) which integrates and extends socio-cognitive theories of trust, reputation and recommendation with basic economic theory.
• results from two simulation studies investigating the performance of SID and the CScEF.
The results show the production of a generic, reusable and scalable platform for developing and animating agent societies, and its contribution to the community as an open source tool. Secondly specific results, regarding the application of SID and CScEF, show that revealing outcomes of using socio-technical mechanisms to condition agent interactions can be demonstrated and identified by using Presage.Open Acces
Contributions to Edge Computing
Efforts related to Internet of Things (IoT), Cyber-Physical Systems (CPS), Machine to Machine (M2M) technologies, Industrial Internet, and Smart Cities aim to improve society through the coordination of distributed devices and analysis of resulting data. By the year 2020 there will be an estimated 50 billion network connected devices globally and 43 trillion gigabytes of electronic data. Current practices of moving data directly from end-devices to remote and potentially distant cloud computing services will not be sufficient to manage future device and data growth.
Edge Computing is the migration of computational functionality to sources of data generation. The importance of edge computing increases with the size and complexity of devices and resulting data. In addition, the coordination of global edge-to-edge communications, shared resources, high-level application scheduling, monitoring, measurement, and Quality of Service (QoS) enforcement will be critical to address the rapid growth of connected devices and associated data.
We present a new distributed agent-based framework designed to address the challenges of edge computing. This actor-model framework implementation is designed to manage large numbers of geographically distributed services, comprised from heterogeneous resources and communication protocols, in support of low-latency real-time streaming applications. As part of this framework, an application description language was developed and implemented. Using the application description language a number of high-order management modules were implemented including solutions for resource and workload comparison, performance observation, scheduling, and provisioning. A number of hypothetical and real-world use cases are described to support the framework implementation
RIXA - Explaining Artificial Intelligence in Natural Language
Natural language is the instinctive form of communication humans use among each other. Recently large language
models have drastically improved and made natural language
interfaces viable for all kinds of applications. We argue that
the use of natural language is a great tool to make explainable
artificial intelligence (XAI) accessible to end users. We present
our concept and work in progress implementation of a new kind
of XAI dashboard that uses a natural language chat. We specify 5
design goals for the dashboard and show the current state of our
implementation. The natural language chat is the main form of
interaction for our new dashboard. Through it the user should be
able to control all important aspects of our dashboard. We also
define success metrics we want to use to evaluate our work. Most
importantly we want to conduct user studies because we deem
them to be the best method of evaluation for end-user-centered
application
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