Hierarchical Approach to Dependability Analysis of Information Systems by Modeling and Simulation

Abstract

The paper presents a method of analyzing functionality aspects of complex information systems. The system analysis is based on integrating different computer system models, the networked systems and applications model, clients behavior model and collaboration between services in the analyzed system, into one coherent functionality based view suitable for system simulation. Modeling process incorporates hierarchical approach, i.e. the system is decomposed into groups of hosts and therefore groups of services, called molecules. The model is described in design by authors XML Domain Modeling Language (XDML). The integrated model is automatically transformed into an input file for modified SSFNet simulator. Additional information on input models could be read from other models or the user could play with all parameters of the XDML model. The paper presents developed software which implements described methodology and results of analysis for an exemplar information system.

Network Systems Analysis in Case of Critical Situations

“…The paper describes approach based on functional-dependability models understood as a concept of specifying dependability aspect for two perspectives: secure and dependable system as much as service-related operational system. In our research, we focus on two types of service models, that where close to our interest area: Discrete Transport System (DTS) [13,14,15,16,17] and Computer Information System (CIS) [8,10,11,12]. Both systems can be analysed separately, but because of their specific goal, some common mechanisms can be seen.…”

“…Some resources, for example the central processors in computer systems, are "time-sharable". This is a technique that allows sharing of resources that are essentially non-sharable, by very fast switching of the allocation in time [1,10,11].…”

Information Systems Configuration Analysis using Event-driven Computer Simulation

“…Service oriented complex information system (SOCIS) aims to fulfill user needs in case of its request. In this kind of systems, user request mainly perform by business service level of the system [5]. In this case we can speak about specified queue for the task realization (choreography) since each task is done using one or more service components that interact with each other.…”