Software fault tolerance is a means of achieving high dependability for mission and safety critical systems. Despite continuing efforts to prevent and remove faults during software development, application-level fault tolerance measures are still required to avoid failures due to residual design, programming and transient faults. In addition to functional complexity of application level software, non-functional requirements, such as diversity, redundancy, exception handling, voting and adjudication mechanisms, are introduced by fault tolerance measures, bringing additional system complexity. Current software patterns, styles and architectures do not respect the separation of concerns at design and programming layers which is desirable when striving to manage complexity, maintainability and portability issues. Moreover the lack of domain specific fault tolerance schemes, like error detection and recovery mechanisms, further makes this task complicated for developers. The main contribution of this research is to provide architectural support for software fault tolerance using an Aspect Oriented Software Development paradigm. The approach used proposes aspect oriented fault tolerance frameworks incorporating exception handling, design diversity and protective wrappers to fulfil the needs of a large range of dependable applications. The utilization of the proposed frameworks IS demonstrated to offer several advantages, involving modularization, reduced complexity, and reusability, over traditional, ad-hoc fault tolerant implementations. Three separate case studies are used to evaluate the proposed frameworks through dependability assessment and software metrics analysis. The results show that the proposed frameworks can improve dependability with higher fault coverage and better separation of fault tolerance concerns from core functionality.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:524697 |
| Date | January 2010 |
| Creators | Hameed, Kashif |
| Publisher | University of the West of England, Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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