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.
Analyses of the interactions among quality requirements (QRs) have often found that optimizing on one QR will cause serious problems with other QRs. As just one relevant example, one large project had an Integrated Product Team optimize the system for Security. In doing so, it reduced its vulnerability profile by having a single-agent key distribution system and a single copy of the data base – only...
It is becoming more common to see software applications taking advantage of the many RESTful web services available publicly to meet their needs rather than developing an in-house solution. This introduces the problem where failures can occur in the network or on the service provider outside the influence of a developer. This paper introduces a reliability-aware framework with a focus on availability...
Processes constrain developer freedom and impact software development cost. They can increase costs from only a few cents to almost 1000 USD per line of code. But they can also benefit the maintainability, dependability and safety of critical software. If failure risk costs are high, then the application of more expensive processes can actually reduce costs. Therefore it is important to understand...
Switches and crossings (S&Cs) connect the rail network, guiding trains from one track to another and supporting path crossing. They are critical systems given the frequency of their functional failure and the consequences on the operation, cost and safety of railway transportation. Reliability studies are required to support the transport objective of providing dependable, sustainable and cost...
Software architecture has become an increasingly important research topic in recent years. Concurrently much more attention has been paid to methods of evaluating non functional attributes of these architectures. However, in current architectural description languages (ADLs) based on a formal and abstract model of system behavior, there is a notable lack of support for representing and reasoning about...
While workload characterization and performance of web systems have been studied extensively, reliability has received much less attention. In this paper, we propose a framework for session reliability modeling which integrates the user view represented by the session layer and the system view represented by the service layer. A unique characteristic of the session layer is that, in addition to the...
Evaluating complex systems is not possible in absence of powerful software tools. RAPTOR (Rapid Availability Prototyping for Testing Operational Readiness) is a generic simulation product developed by ARINC that predicts reliability, maintainability and availability performance of systems and components. The author considers RAPTOR as being uniquely suited for evaluating communication network system...
This paper investigates the reliability of wireless sensor networks, deployed over a square area, in regards to two aspects: network connectivity and node failures. Analyzing the phenomenon known as the border effects on the connectivity of such networks, we derive exact expressions for the expected effective connectivity degree of border nodes. We show that the relative average number of neighbors...
This paper proposes a model to quantify the reliability of web services. Based on their structures, web services can be classified into the following two kinds: atomic web service which calls no other web services and composite web service consisting of atomic web services. The model first evaluates the reliability of atomic web services from the consumers' perspective. After that this paper points...
This paper considers the estimation of reliability and availability of intrusion-tolerant systems subject to non-detectable intrusions. Our motivation comes from the observation that typical techniques of intrusion tolerance may in certain circumstances worsen the non-functional properties they were meant to improve (e.g., dependability). We start by modeling attacks as adversarial efforts capable...
Web services are increasingly used to integrate and build business application on the internet. Failure of web services is not acceptable in many situations such as online banking, so fault tolerance is a key challenge of web services. Web service architecture still lacks facilities to support fault tolerance. This paper proposes a fault tolerant architecture for web services by increasing the reliability...
Components can be assembled based on the Service-Oriented Architecture (SOA), which allows enterprises to specify their services in a finer granularity, thus the services can be expressed in a deeper and more comprehensive manner. This paper makes use of the formal description of the service component, the Hierarchical Automata, studies the importance factors of each component and roughly categorizes...
The availability and reliability of Service-oriented architectures (SOA) depends on two factors: On the one hand, the availability and reliability of the services that provide a certain business functionality and on the other hand the services that make up the underlying SOA platform. For platforms that are supposed to form the core of mission-critical service-oriented applications, this implicates...
By incorporating the chip multi-threading (CMT) and operating system predictive self-healing technologies, the Sun CMT/Solaris based servers are not only cost/performance effective, but also more robust in reliability, availability, and serviceability (RAS) than the X86/Linux servers with similar performance. The differentiators include higher levels of hardware integration, more fault tolerance provisions...
We present a quantitative method based on stochastic Petri net (SPN) to evaluate the survivability of distributed service. Three types of combination service models: one-to-one, one-to-N, and M-to-N are studied, which can reflect survivability of distributed service from a different perspective. Absorbing-state reliability, maintainability and steady-state availability are considered as measures of...
A large-scale distributed system may experience software or hardware failures that lead to undesirable down-time of the system. While the failure of a hardware node is common for large distributed systems, the reliability of software can also be a significant factor. System reliability can be improved by integrating both hardware and software based reliability techniques. We presented a combined fault-tolerant...
Future network systems and embedded infrastructure devices in ubiquitous environments will need to consume low power and process large amounts of network packet traffic. In order to meet necessary high processing efficiency requirements, future processors will have many heterogeneous cores with reduced reliability due to low voltage, small transistor sizes, semiconductor wearout, and environmental...
In this paper we tackle several problems regarding efficient data replication in distributed systems. In the first part, we consider several theoretical offline data replication and reliability improvement problems, for which we present novel, efficient, algorithmic solutions (e.g. replication in tree networks and reliable replication strategies). In the second part we address a concrete data replication...
Mobile peer to peer (P2P) computing is becoming a major revolution in computing owing to advances in computing power, network connectivity and storage capacity of mobile devices. Mobile workflow is, however, characterized by the unreliability of mobile peers who can drop out of the network due to sudden loss of connectivity, drained battery and so on, thus making problematic the guaranteed completion...
Dependability is a broad concept which covers such aspects of computer systems like reliability, maintainability, and availability. Also because of this broadness, researches came up with related yet more focused notions such as self-healing and robustness. In this article, I discuss robustness in relation to dependability and make a distinction between these two. I outline the state of the art of...
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.