The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Policies have been identified as one possible way to specify to management systems the operational constraints of a system or systems being managed. Such policies, often characterized as event-triggered condition actions rules, are frequently defined via policy languages and or user interface tools in order to simplify their expression and understanding by system administrators. The underlying assumption...
Quality of individual services is substantial to guarantee high performance and availability of overall composite service oriented systems. This requires the process of diagnosing service quality degradation and responding to it in a timely and non-stopping manner. This paper presents a modeling-based approach to coordinate the process of Web service management, configuring parameters or invoking...
Several approaches have been proposed to introduce self-management capabilities for Web service compositions.However, most of these works are limited as they are not extensible, i.e., new self-adaptation features cannot be supported, and even if that is possible then still this cannot be done dynamically while the composite services are running.In addition, many of these works are not based on the...
In this paper we investigate the formalisation of distributed and long-running stateful systems using our normative temporal specification framework. We analyse aspects of a component-oriented Grid system, and the benefits of having a logic-based tool to perform automated and safe dynamic reconfiguration of its components. We describe which parts of this Grid system are involved in the reconfiguration...
It is well recognized that debugging or testing a distributed system is a great challenge. FiLM is a runtime monitoring tool that can monitor the execution of distributed applications against LTL specifications on finite traces. Implemented within the online predicate checking infrastructure D3S, FiLM models the execution of distributed applications as a trace of consistent global snapshots with global...
Static analysis is one of the most popular approaches of software analysis. As more and more software protects their code by transformation or encryption, then releases them at runtime dynamically, it is hard to statically analyze these protected executables because of the failure of disassembling. In this paper, we propose a novel and general technique to reconstruct binary files for static analysis...
Dynamic program monitoring has been applied in software-intensive systems to detect runtime constraint violations and trigger system recovery actions. Uncontrolled monitoring activities may, however, delay detection of a violation for an unbounded time and, worse, affect the original system's schedulability. In this paper, we introduce the concept of predictable monitoring, which demands a bound on...
Although distributed object systems, including RMI and CORBA, enable object-oriented programs to be easily distributed across a network, achieving acceptable performance usually requires client-specific optimization of server interfaces, making such systems difficult to maintain and evolve. Automatic optimization techniques, including Batched Futures and Communication Restructuring, do not work as...
Wireless sensor network coverage completeness is an important Quality of Service measure. It is frequently assumed that events occurring in the sensor field will always be detected. However, this is not necessary the case, particularly if there are holes in the sensor network coverage. This paper introduces a novel method for detection and relative localization of sensor network coverage holes in...
The online detection of anomalies is a vital task in data centers, potentially incurring high personnel costs. Causes of anomalies range from hardware/software failures, to resource over- or under-provisioning, to application misbehaviors. This paper develops new methods and an associated utility for online anomaly detection, termed EbAT, entropy based anomaly tester, which can efficiently detect...
Monitoring the preservation of security and dependability (S&D) properties during the operation of systems at runtime is an important verification measure that can increase system resilience. However it does not always provide sufficient scope for taking control actions against violations as it only detects problems after they occur. In this paper, we describe a proactive monitoring approach that...
Research literature has argued the need for a methodology to measure security assurance levels of a system as vital in order to maintain and improve the overall system security. Building on our close examination of the existing approaches for IT Information assurance, this paper proposes a risk-based security assurance metrics and aggregation techniques to be incorporated in a methodology for the...
Programmers hoping to exploit multi-core processors must split their applications into threads suitable for independent, concurrent execution. The lock-based concurrency of many existing languages is clumsy and error prone - a barrier to writing fast and correct concurrent code. The Actor model exudes concurrency - each entity in the model (an Actor) executes concurrently. Interaction is restricted...
In open systems, certain unfavorable situations due to unanticipated user behavior may be seen, which results in a violation of cross-cutting policy. This paper proposes a runtime monitoring method to check such problems. Since there is a large gap, a certain link is needed between the policy and runtime execution method. We employ a two-step checking approach; an offline symptom checking and a runtime...
As modern supercomputing systems reach the peta-flop performance range, they grow in both size and complexity. This makes them increasingly vulnerable to failures from a variety of causes. Checkpointing is a popular technique for tolerating such failures, enabling applications to periodically save their state and restart computation after a failure. Although a many automated system-level checkpointing...
Lightweight fault-localization techniques use program coverage to isolate the parts of the code that are most suspicious of being faulty. In this paper, we present the results of a study of three types of program coverage-statements, branches, and data dependencies-to compare their effectiveness in localizing faults. The study shows that no single coverage type performs best for all faults-different...
An Organic Computing system has the ability to autonomously (re-)organize and adapt itself. Such a system exhibits so called self-x properties (e.g. self-healing) and is therefore more dependable as e.g. some failures can be compensated. Furthermore, it is easier to maintain as it automatically configures itself and more convenient to use because of its automatic adaptation to new situations. Design...
Evaluation of runtime object states against the model-level states defined in a state model is critical to state based test automation. This paper presents a state mapping framework to support the automated state-based test execution process. The framework automatically keeps track of runtime object states and maps these states to model-level abstract states. It also includes a comparator to determine...
We present a middleware platform for assembling pervasive applications that demand fault-tolerance and adaptivity in distributed, dynamic environments. Unlike typical adaptive middleware approaches, in which sophisticated component model semantics are embedded into an existing, underlying platform (e.g., CORBA, COM, EJB), we propose a platform that imposes minimal constraints for greater flexibility...
For a system of distributed processes, correctness can be ensured by (statically) checking whether their composition satisfies properties of interest. However, Web services are distributed processes that dynamically discover properties of other Web services. Since the overall system may not be available statically and since each business process is supposed to be relatively simple, we propose to use...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.