Andrey A. Shchurov

Andrey A. Shchurov, Radek Marik, Vladimir A. Khlevnoy

Deployment of network/distributed systems sets high requirements for procedures, tools and approaches for the complex testing of these systems. This work provides a survey of testing activities with regard to these systems based on standards and actual practices for both software-based and distribution (network) aspects. On the basis of this survey, we determine formal testing procedures/processes which cover these aspects, but which are not contrary to both aspects. The next step, based on the analysis of the implementation phase of System Development Life Cycle, determines a formal model for these processes

Andrey A. Shchurov, Radek Marik

Nowadays, the consequences of failure and downtime of distributed systems have become more and more severe. As an obvious solution, these systems incorporate protection mechanisms to tolerate faults that could cause systems failures and system dependability must be validated to ensure that protection mechanisms have been implemented correctly and the system will provide the desired level of reliable service. This paper presents a systematic approach for identifying (1) characteristic sets of critical system elements for dependability testing (single points of failure and recovery groups) based on the concept of layered networks; and (2) the most important combinations of components from each recovery group based on a combinatorial technique. Based on these combinations, we determine a set of test templates to be performed to demonstrate system dependability.

Andrey A. Shchurov

Fault tolerance is a key factor of industrial computing systems design. But in practical terms, these systems, like every commercial product, are under great financial constraints and they have to remain in operational state as long as possible due to their commercial attractiveness. This work provides an analysis of the instantaneous failure rate of these systems at the end of their life-time period. On the basis of this analysis, we determine the effect of a critical increase in the system failure rate and the basic condition of its existence. The next step determines the maintenance scheduling which can help to avoid this effect and to extend the system life-time in fault-tolerant mode.

Vladimir A. Khlevnoy, Andrey A. Shchurov

Deployment of distributed systems sets high requirements for procedures for the security testing of these systems. This work introduces: (1) a list of typical threats based on standards and actual practices; (2) an extended six-layered model for test generation mission on the basis of technical specifications and end-user requirements. Based on the list of typical threats and the multilayer model, we describe a formal approach to the automated design and generation of security mechanisms checklists for complex distributed systems.

Andrey A. Shchurov, Radek Marik

Deployment of distributed systems sets high requirements for procedures and tools for the complex testing of these systems. This work introduces a formal four-layered model for test generation mission on the basis of the component-based approach and the concept of layered networks. Based on this model, we describe the test generation strategy that covers every interaction from the end-user requirements on all coexisting architectural layers, and checks the internal consistency of the system technical specifications with respect to the end-user requirements. The next step introduces the Prolog-based approach to representing this model and the requirements-coverage strategy

Andrey A. Shchurov

Nowadays, deployment of distributed systems sets high requirements for procedures and tools for the complex testing of these systems - virtualization and cloud technologies make another level of system complexity. As a possible solution, it is necessary to determine a formal list of control objectives - checklists. The automated generation of checklists involves analyzing system models (with the analysis covering paths in a model). But complex distributed systems are usually a set of coexisting topologies which interact and depend on each other and it is necessary to use several models in order to cover different aspects. This work introduces a formal four layered model for test generation missions on the basis of the component-based approach and the concept of layered networks. The interlayer mapping determines how the topological properties on different layers affect each other and, as a consequence, represents technologies (virtualization, clustering, etc.) used to build distributed systems