1,579 research outputs found
Programming distributed and adaptable autonomous components--the GCM/ProActive framework
International audienceComponent-oriented software has become a useful tool to build larger and more complex systems by describing the application in terms of encapsulated, loosely coupled entities called components. At the same time, asynchronous programming patterns allow for the development of efficient distributed applications. While several component models and frameworks have been proposed, most of them tightly integrate the component model with the middleware they run upon. This intertwining is generally implicit and not discussed, leading to entangled, hard to maintain code. This article describes our efforts in the development of the GCM/ProActive framework for providing distributed and adaptable autonomous components. GCM/ProActive integrates a component model designed for execution on large-scale environments, with a programming model based on active objects allowing a high degree of distribution and concurrency. This new integrated model provides a more powerful development, composition, and execution environment than other distributed component frameworks. We illustrate that GCM/ProActive is particularly adapted to the programming of autonomic component systems, and to the integration into a service-oriented environment
Middleware-based Database Replication: The Gaps between Theory and Practice
The need for high availability and performance in data management systems has
been fueling a long running interest in database replication from both academia
and industry. However, academic groups often attack replication problems in
isolation, overlooking the need for completeness in their solutions, while
commercial teams take a holistic approach that often misses opportunities for
fundamental innovation. This has created over time a gap between academic
research and industrial practice.
This paper aims to characterize the gap along three axes: performance,
availability, and administration. We build on our own experience developing and
deploying replication systems in commercial and academic settings, as well as
on a large body of prior related work. We sift through representative examples
from the last decade of open-source, academic, and commercial database
replication systems and combine this material with case studies from real
systems deployed at Fortune 500 customers. We propose two agendas, one for
academic research and one for industrial R&D, which we believe can bridge the
gap within 5-10 years. This way, we hope to both motivate and help researchers
in making the theory and practice of middleware-based database replication more
relevant to each other.Comment: 14 pages. Appears in Proc. ACM SIGMOD International Conference on
Management of Data, Vancouver, Canada, June 200
Enabling the Autonomic Management of Federated Identity Providers
The autonomic management of federated authorization infrastructures (federations) is seen as a means for improving the monitoring and use of a service provider’s resources. However, federations are comprised of independent management domains with varying scopes of control and data ownership. The focus of this paper is on the autonomic management of federated identity providers by service providers located in other domains, when the identity providers have been diagnosed as the source of abuse. In particular, we describe how an autonomic controller, external to the domain of the identity provider, exercises control over the issuing of privilege attributes. The paper presents a conceptual design and implementation of an effector for an identity provider that is capable of enabling cross-domain autonomic management. The implementation of an effector for a SimpleSAMLphp identity provider is evaluated by demonstrating how an autonomic controller, together with the effector, is capable of responding to malicious abuse
A Middleware Framework for Constraint-Based Deployment and Autonomic Management of Distributed Applications
We propose a middleware framework for deployment and subsequent autonomic
management of component-based distributed applications. An initial deployment
goal is specified using a declarative constraint language, expressing
constraints over aspects such as component-host mappings and component
interconnection topology. A constraint solver is used to find a configuration
that satisfies the goal, and the configuration is deployed automatically. The
deployed application is instrumented to allow subsequent autonomic management.
If, during execution, the manager detects that the original goal is no longer
being met, the satisfy/deploy process can be repeated automatically in order to
generate a revised deployment that does meet the goal.Comment: Submitted to Middleware 0
Towards Autonomic Service Provisioning Systems
This paper discusses our experience in building SPIRE, an autonomic system
for service provision. The architecture consists of a set of hosted Web
Services subject to QoS constraints, and a certain number of servers used to
run session-based traffic. Customers pay for having their jobs run, but require
in turn certain quality guarantees: there are different SLAs specifying charges
for running jobs and penalties for failing to meet promised performance
metrics. The system is driven by an utility function, aiming at optimizing the
average earned revenue per unit time. Demand and performance statistics are
collected, while traffic parameters are estimated in order to make dynamic
decisions concerning server allocation and admission control. Different utility
functions are introduced and a number of experiments aiming at testing their
performance are discussed. Results show that revenues can be dramatically
improved by imposing suitable conditions for accepting incoming traffic; the
proposed system performs well under different traffic settings, and it
successfully adapts to changes in the operating environment.Comment: 11 pages, 9 Figures,
http://www.wipo.int/pctdb/en/wo.jsp?WO=201002636
A Framework for Constraint-Based Deployment and Autonomic Management of Distributed Applications
We propose a framework for deployment and subsequent autonomic management of
component-based distributed applications. An initial deployment goal is
specified using a declarative constraint language, expressing constraints over
aspects such as component-host mappings and component interconnection topology.
A constraint solver is used to find a configuration that satisfies the goal,
and the configuration is deployed automatically. The deployed application is
instrumented to allow subsequent autonomic management. If, during execution,
the manager detects that the original goal is no longer being met, the
satisfy/deploy process can be repeated automatically in order to generate a
revised deployment that does meet the goal.Comment: Submitted to ICAC-0
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