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.
Cloud computing initiates various opportunities and challenges for information technology industry. Due to distributed and virtualized environment of cloud, component failures are quite common phenomena. These failures usually lead to sporadic downtime and degrade the availability level of cloud services. Availability of service is stipulated in the Service Level Agreement (SLA) and calculated as...
Based on the stochastic high level Petri net, this paper put forward a new availability model of Web-server Clusters. This model facilitates availability analysis of per service type and whole services. Through the Numerical analysis, we find that different load distribution and scheduling algorithm has different availability under same loads.
In this paper we present and analyse a coloured stochastic Petri net model of a redundant fault-tolerant system. As our measure of interest we are interested in a dependability metric, i.e., service availability. Service availability is defined as the number of successfully completed jobs relative to the total number of arrived jobs. This paper is the first step towards a comprehensive comparison...
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...
This paper proposes compositional stochastic models for an intrusion tolerant system to evaluate quantitative security measures for security. The models are described by MRSPNs (Markov regenerative stochastic Petrinets), which have high representation ability. Through modeling of an intrusion tolerant system, we present standardized components using MRSPNs, which would be useful to evaluate security...
Cluster system has become infrastructure, which constructs high performance distributed systems. The quality of service (QoS) that offers for users will be affected by dependability at large. Stochastic Petri nets (SPN) is a kind of flexible modeling tool, and it has established matured theory system on the research of dependability. The SPN is taken advantage of to model front-end dispatcher and...
In this paper we present a queueing model for service availability formulated as a Petri net. We define a metric for service availability and show how it can be estimated from the model. Assuming that a failure avoidance mechanism is present, we analyze the distribution of time-to-failure. Finally, we show in experiments how service availability depends on queue length, utilization and failure prevention...
In this paper we present a queuing model to investigate the effect of time-based system rejuvenation on service availability. The model is formulated as a stochastic colored Petri net, which allows us to use realistic distributions such as the lognormal distribution. We define a metric for service availability and derive how it can be estimated from the model. Experiments show that the optimal rejuvenation...
The objective of this paper is to provide a first analysis of the effectiveness of simple server replication vs. failure prevention in non-high-availability applications. We analyze service availability for a system with N servers where each server is modeled as a finite queue subject to failures. A Petri net analysis suggests that service availability is most effectively improved by server duplication,...
Fault-Tolerant capacity of the key server will effect integrality and restorability of the data in network system, so in order to increase system's availability, cluster technique has been adopted widely. In despite of achieving high system availability with cluster technique, it makes system very complexly and availability analysis very difficult. By analyzing redundant server system's structure...
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.