This paper presents a novel architectural solution for improving dependability of Web Services. This approach is based on the concepts from the emerging resilienceexplicit computing combined with the traditional fault-tolerance techniques such as recovery blocks and N-version programming applied in the context of the serviceoriented architecture. We propose a distributed solution called WS-Medi...

If we take a look at current cloud computing services, the only quality guarantee they provide are vague Service Level Agreements(SLA). In this paper we modelled some non-functional aspects in an ontology and used this ontology as a knowledge base to generate an excerpt from a service contract. We concentrate in this excerpt on availability as it is one of the most discussed attributes in curre...

Most part of the existing analytical models to predict service reliability and availability assume a static behavior of the service and do not take into account the correlation between the invoked system components. In order to take into account the dynamic aspects of a service as functional chains, operational processes and logistic support, a hybrid approach is here introduced: a dynamic SERA...

The availability of an organisation’s IT infrastructure is of vital importance for supporting business activities. IT outages are a cause of competitive liability, chipping away at a company financial performance and reputation. To achieve the maximum possible IT availability within the available budget, organisations need to carry out a set of analysis activities to prioritise efforts and take...

—Availability, as a part of Service Level Agreement (SLA), is a critically important issue in cloud services, which are affected by server or network failures in datacenters. Cloud service providers seek to not only fulfill the SLA, but also simultaneously minimize their operating costs, which are dominated by the energy consumption. In order to minimize the impact of a server/switch failure o...

to determine the coverage rate, timeliness and quality of ante-natal care in rural areas under the coverage of health houses in west azerbaijan province, 30 health houses (hh) were randomly selected out of 731 hh in the province. in each hh, using the method of lot quality assurance sampling (lqas) 28 women having recently born babies was selected. data were collected using check-list for facil...