Software - Implemented Self-healing System

The term “Self-healing” denotes the capability of a software system in dealing with bugs. Fault tolerance for dependable computing is to provide the specified service through rigorous design whereas self-healing is meant for run-time issues. The paper describes various issues on designing a self-healing software application system that relies on the on-the-fly error detection and repair of web application or service agent code and data. Self-Healing is a very new area of research that deals with fault tolerance for dynamic systems. Self-healing deals with imprecise specification, uncontrolled environment and reconfiguration of system according to its dynamics. Software, which is capable of detecting and reacting to its malfunctions, is called self-healing software. Such software system has the ability to examine its failures and to take appropriate corrections. Self-Healing system must have knowledge about its expected behavior in order to examine whether its actual behavior deviates from its expected behavior in relation of the environment. A fault-model of Self-Healing system is to state what faults or injuries to be self-healed including fault duration, fault source such as, operational errors, defective system requirements or implementation errors etc. Self-healing categories of aspects include fault-model or fault hypothesis, System-response, System-completeness and Design-context. Based on many important literatures, this paper aims also to illustrate critical points of the emergent research topic of Self – Healing Software System.

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Online Reconfigurable Self-Timed Links for Fault Tolerant NoC

VLSI Design ◽

10.1155/2007/94676 ◽

2007 ◽

Vol 2007 ◽

pp. 1-13 ◽

Cited By ~ 70

Author(s):

Teijo Lehtonen ◽

Pasi Liljeberg ◽

Juha Plosila

Keyword(s):

Fault Tolerance ◽

Error Detection ◽

Fault Tolerant ◽

Fault Model ◽

Recovery Method ◽

Transient Errors ◽

Permanent Faults ◽

Modular Redundancy ◽

The Cost ◽

Previous Error

We propose link structures for NoC that have properties for tolerating efficiently transient, intermittent, and permanent errors. This is a necessary step to be taken in order to implement reliable systems in future nanoscale technologies. The protection against transient errors is realized using Hamming coding and interleaving for error detection and retransmission as the recovery method. We introduce two approaches for tackling the intermittent and permanent errors. In the first approach, spare wires are introduced together with reconfiguration circuitry. The other approach uses time redundancy, the transmission is split into two parts, where the data is doubled. In both structures the presence of permanent or intermittent errors is monitored by analyzing previous error syndromes. The links are based on self-timed signaling in which the handshake signals are protected using triple modular redundancy. We present the structures, operation, and designs for the different components of the links. The fault tolerance properties are analyzed using a fault model containing temporary, intermittent, and permanent faults that occur both as bursts and as single faults. The results show a considerable enhancement in the fault tolerance at the cost of performance and area, and with only a slight increase in power consumption.

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An Autonomic Approach to Enhance Web Application Availability

10.21203/rs.3.rs-31808/v1 ◽

2020 ◽

Author(s):

Hussam N. Fakhouri

Keyword(s):

Operating System ◽

Web Application ◽

Recovery Time ◽

Autonomic Computing ◽

Web Applications ◽

The Self ◽

Software Systems ◽

Self Healing ◽

Healing System ◽

The Web

Abstract Autonomic computing is one of the fascinating features that enable the system to automatically manage itself, diagnose itself, detect the error that cause the failure, then recover and reconfigure the system. The concept of software, systems and web self healing is widely used in many software such as windows operating system which restores and recover tools. Since of the aim of the self healing software feature is to fast recover the application and keep running it and available for 24/7 as optimal as possible then it will a suitable to apply this capability to the web applications to fast recover from any unexpected change that may happen. This paper proposes a self-healing system that monitor, diagnose, check and heal web applications automatically and immediately with unnoticeable recovery time. To test the practical applicability of the proposed methodology, an application has been developed to demonstrate the methodology and apply it for real time web applications. The results of experiments performed on different scenarios demonstrated the ability of the proposed approach to heal web applications and to increase its availability.

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ANALYZING AND IMPROVING WEB APPLICATION QUALITY USING DESIGN PATTERNS

INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY ◽

10.24297/ijct.v2i2b.2641 ◽

2012 ◽

Vol 2 (2) ◽

pp. 112-116

Author(s):

Shikha Bhatia ◽

Mr. Harshpreet Singh

Keyword(s):

Web Application ◽

Design Pattern ◽

Design Patterns ◽

Web Applications ◽

Past Research ◽

Software Systems ◽

Interactive Software ◽

Web Based ◽

Software Application ◽

Execution Speed

With the mounting demand of web applications, a number of issues allied to its quality have came in existence. In the meadow of web applications, it is very thorny to develop high quality web applications. A design pattern is a general repeatable solution to a generally stirring problem in software design. It should be noted that design pattern is not a finished product that can be directly transformed into source code. Rather design pattern is a depiction or template that describes how to find solution of a problem that can be used in many different situations. Past research has shown that design patterns greatly improved the execution speed of a software application. Design pattern are classified as creational design patterns, structural design pattern, behavioral design pattern, etc. MVC design pattern is very productive for architecting interactive software systems and web applications. This design pattern is partition-independent, because it is expressed in terms of an interactive application running in a single address space. We will design and analyze an algorithm by using MVC approach to improve the performance of web based application. The objective of our study will be to reduce one of the major object oriented features i.e. coupling between model and view segments of web based application. The implementation for the same will be done in by using .NET framework.

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Influencing Factors on the Healing Performance of Microcapsule Self-Healing Concrete

Materials ◽

10.3390/ma14154139 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4139

Author(s):

Yanju Wang ◽

Zhiyang Lin ◽

Can Tang ◽

Wenfeng Hao

Keyword(s):

Compressive Strength ◽

Sodium Silicate ◽

Recovery Rate ◽

Sound Speed ◽

Orthogonal Experimental Design ◽

Self Healing ◽

Damage Degree ◽

Strength Recovery ◽

Healing System ◽

Recovery Performance

The amounts of the components in a microcapsule self-healing system significantly impact the basic performance and self-healing performance of concrete. In this paper, an orthogonal experimental design is used to investigate the healing performance of microcapsule self-healing concrete under different pre-damage loads. The strength recovery performance and sound speed recovery performance under extensive damage are analyzed. The optimum factor combination of the microcapsule self-healing concrete is obtained. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are carried out on the concrete samples before and after healing to determine the healing mechanism. The results show that the healing effect of self-healing concrete decreases with an increase in the pre-damage load, and the sound speed recovery rate increases with an increase in the damage degree. The influence of the sodium silicate content on the compressive strength and compressive strength recovery rate of the self-healing concrete increases, followed by a decrease. The optimum combination of factors of the microcapsule self-healing system is 3% microcapsules, 30% sodium silicate, and 15% sodium fluosilicate. The results can be used for the design and preparation of self-healing concrete.

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Towards a New Semantic Metric for Error Detection Based on Program State Redundancy

International Journal of Systems and Service-Oriented Engineering ◽

10.4018/ijssoe.2021070101 ◽

2021 ◽

Vol 11 (2) ◽

pp. 1-23

Author(s):

Dalila Amara Amara ◽

Latifa Ben Arfa Rabai

Keyword(s):

Fault Tolerance ◽

Empirical Study ◽

Error Detection ◽

Final States ◽

Internal States ◽

Common Concept ◽

Program Redundancy ◽

Semantic Metrics

Fault tolerance techniques are generally based around a common concept that is redundancy whose measurement is required. A suite of four semantic metrics is proposed to assess program redundancy and reflect their ability to tolerate faults. Literature shows that one of these metrics, namely state redundancy, is limited to compute program redundancy only in their initial and final states and ignores their internal states. Consequently, the authors focus in this paper to overcome this shortcoming by proposing a new redundancy-based semantic metric that computes the redundancy of the different program states including internal ones. The empirical study they perform shows that the proposed metric is a measure of program redundancy in one side and is an error detection indicator in another side. Moreover, they demonstrate that it is more accurate than the basic state redundancy metric in detecting masked errors. It is useful for testers to indicate if a tested program is error-free and to pinpoint the presence of masked errors even if the final states are equal to the expected ones.

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