Efficient modeling and optimizing of checkpointing in concurrent component-based software systems

SummaryCheckpoint‐based fault‐tolerant (FT) methods have been widely used to enhance the reliability of stream processing systems, but a checkpointing process usually introduces considerable overhead. It is a critical issue to choose the optimal checkpoint interval (OCI) that maximizes the processing efficiency. Traditional OCI models consider the recovery time equals to the execution time from the last checkpoint to the failure moment. However, for stream processing jobs, the recovery time is related to reprocessing workloads, depending on the real‐time input data before a failure. A new model is needed to choose the OCI for stream processing applications. Moreover, the input data rate of a stream processing job fluctuates over time. To solve these problems, we present a novel DSPS OCI (DOCI) model in this paper. We prove that it maximizes the processing efficiency for a given time. We propose an approach to dynamically adjust the OCI for an application to accommodate the workload fluctuations. We conduct simulation experiments to verify the effectiveness of our DOCI model and the efficiency of the online OCI adjustment algorithm. Experimental results with a real‐world dataset show that DOCI achieves an improvement on system efficiency by up to 32%, compared with existing FT approaches.

While interconnected systems proliferate in nowadays computing and communications technology there are few reports investigating their security. In this paper, new efficient models are developed and evaluated for analyzing the security-related behavior of computing architectures and networks comprising complex interconnected communication systems adapted towards a generalized analysis. These models, based on Markov processes, allow calculation of critical security factors, related to intrusion detection, of such interconnected systems components and the evaluation of the associated security mechanisms. Although, at this step two interconnected systems are analyzed, the systematic model introduced allows for a generalized model of N interconnected systems. We herein show the principles of such an analysis. Security parameters calculation and Security mechanisms evaluation may support the risk analysis and the decision making process in resolving the trade-offs between security and quality of service characteristics corresponding to the complex interconnected computing and communication systems.

Software development communities have made the true venture to software development through the concept of component-based software approach and commercial off-the-shelf (COTS). Majority of the present software applications have software components as the basic elements, and component-based software development (CBSD) has been successful in building applications and systems. However, the security of CBS for the software component is still not properly noticed. Developing secure software is the accountability of all the stakeholders involved with component-based software development model. The main challenge is to access how much security we have achieved or how can we predict and evaluate the security at the early stage of software development? Software security has a very constructive impact on software productivity, maintainability, cost, and quality. Therefore, more early we introduce and evaluate security into component-based software more productivity and quality we can achieve. In this paper, efforts are done to provide some suitable guiding principle to the software engineers in the development of secure component-based software products. This paper also discusses the overview of requirement specification and analyzes the software architectures and design for developing secure component-based software products.

Many regard widespread development and reuse of software components as one of the next biggest phenomena for software. However, widespread reuse of a software component with poor quality may lead to disasters. Improper reuse of software components of good quality may also be disastrous. Testing and quality assurance is therefore critical for both software components and component-based software systems. This tutorial provides an in-depth look at the technical issues, challenges, managerial aspects, and needs in testing of components and systems. Moreover, this tutorial reports on the recent advances and research efforts in developing new solutions to solve those problems and meet those needs, from the perspectives of component-based software engineering. The tutorial will discuss the state-of-the-art practice, issues, and challenges, new solutions and research efforts in third-party component testing, component-based program validation, and test automation. The targeted audience includes technical managers, software testing engineers, quality assurance people, and development engineers who are working on component-based software projects. The tutorial will be useful for professionals, researchers, and students interested in understanding the general concepts and methods in component testing and component-based software validation. This tutorial assumes that participants have a general understanding of software engineering and software testing methods, and have some working experience in software development and validation.

Component based software development (CBSD) endeavors to deliver cost-effective and quality software systems through the selection and integration of commercially available software components. CBSD emphasizes the design and development of software systems using preexisting components. Software component reusability is an indispensable part of component based software development life cycle (CBSDLC), which consumes a significant amount of organization’s resources, that is, time and effort. It is convenient in component based software system (CBSS) to select the most suitable and appropriate software components that provide all the required functionalities. Selecting the most appropriate components is crucial for the success of the entire system. However, decisions regarding software component reusability are often made in an ad hoc manner, which ultimately results in schedule delay and lowers the entire quality system. In this paper, we have discussed the analytic network process (ANP) method for software component selection. The methodology is explained and assessed using a real life case study.

Optimal checkpointing interval of a communication system with rollback recovery

A novel approach for component-based fault-tolerant software development

This paper proposes a novel method for achieving a distributed self-refined fault tolerance by dynamically partitioning the processes into smaller groups, which are mutually disjoint and collectively exhaustive of the whole system. The present model provides tolerance for frequent faults, makes the roll back recovery simple and less time consuming. An optimal checkpoint interval is found using a mathematical approximation and a spare process is made to capture all the in-transit messages when a process fails at its ends. Piggybacking the events of dependent processes on the outgoing messages is used for process grouping. A process with maximum information can scatter chunk values to the other dependent processes in its group. Each process constructs a checkpoint when the received chunk matches with its log.

Processor Allocation and Checkpoint Interval Selection in Cluster Computing Systems

As computer communication technology has developed, system control mechanisms have been realized by a number of processors, and, hence, it has become necessary to carry out processing distributively and rapidly. Also, as the system mechanisms have become increasingly complicated, the problems of improving reliability and increasing capabilities have become important. In this paper, we consider a control system which is roughly divided into one mark processor and a group of other processors, and formulate a stochastic model by taking notice of only communications between two processors. We perform scheduled checkpointing and execute rollback recovery to restore the consistency of a whole system when two faults of processor failures and communication errors have occurred. The expected cost is obtained and an optimal checkpoint interval which minimizes it is discussed. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 84(9): 49–55, 2001

In the context of evacuation planning at a strategic level, an efficient model is proposed to augment network capacity under a budget constraint so as to enhance operational performance under a security threat. Contraflow strategies and lane additions are considered for capacity augmentation. The corresponding mathematical programming model is obtained through a case-specific graph theoretic transformation of Daganzo's cell transmission model, exploiting problem characteristics to enhance computational efficiency. This paper focuses on experiments and sensitivity analyses to provide insights: (1) on the computational efficiency of the proposed model; and (2) for strategies for evacuation planning and operations. Sensitivity analyses are performed for a test network in terms of the budget for contraflow operations, the evacuee population size, and the amount and spatial distribution of origin-destination (O-D) demand. The results suggest that there is a threshold budget beyond which benefits, in terms of the network clearance time, are negligible. They also indicate that the network clearance time varies linearly with uniformly distributed population size. Finally, greater spatial uniformity of O-D demand reduces clearance times, suggesting that specifying multiple destinations in the safety zone may lead to more efficient evacuation in many instances. From a response standpoint, the study suggests that operational effectiveness requires predetermined contraflow strategy plans with designated and well-trained personnel, rather than just reacting to a security event in real-time.

One of the oldest yet still not satisfactorily solved problems of reusing existing software components is the unexpected behaviour of the components in component-based software. The reason is that these components are adequately tested for the present situation, that is, within the context they are supposed to be deployed at the moment, but hardly take into account all potentially possible contexts in which they might be deployed in the future. Thus, we must test a component for the context in which it is being reused. We propose an MDA-based framework to perform context-dependent testing of a component (MD-CDT). In MD-CDT, we model the component's usage, in the component-based software, using use cases and interaction diagrams. The test cases for context-dependent testing of the component are automatically generated from these scenarios using a MDA-based tool. We then evaluate the adequacy of these test cases by comparing them with the test suite that component developer had used to perform component testing at the time of component development which is provided as metadata. This comparison identifies weaknesses of component testing which assist us in devising test cases to test the component's functionality which was not fully tested during component testing. Finally, we test the component for the new context by executing the enriched test suite. This approach is novel in that it uses the test suite, which was executed by component developer, to determine the adequacy of the component testing. Another novelty of this approach is the use of the model-driven technology for performing context-dependent testing of components which makes our framework portable, interoperable and maintainable. We provide a prototype implementation of MD-CDT. We evaluate MD-CDT and the prototype tool on Lucene search engine.

A mapping study to investigate component-based software system metrics

In Component-based Software (CBS) development, it is desirable to choose software components that provide all necessary functionalities and at the same time optimize certain nonfunctional attributes of the system (for example, system cost). In this paper we investigate the problem of selecting software components to optimize one or more nonfunctional attributes of a CBS. We approach the problem through the lexicographic multi-objective optimization perspective and develop a scheme that produces Pareto-optimal solutions. Furthermore we show that the Component Selection Problem (CSP) can be solved in polynomial time if the components are connected by serial interfaces and all the objectives are to be minimized, whereas the corresponding maximization problem is NP-hard.

DOI: 10.1049/ic:20040498 ISBN: 0 86341 434 6 Location: Edinburgh, UK Conference date: 25 May 2004 Format: PDF Specifying and enforcing constraints and invariants such as architectural constraints and data typing, strongly enhances the safety and reliability of the software system. Next to design and development constraints, the composition of software systems in component-based software also introduces composition time constraints and dependencies. In data-centered software systems, for example, the software composer implicitly creates dataflow dependencies between software components. Describing composition time constraints and enforcing these constraints at deploy time or at run-time strongly improves the safety and reliability of the software. In this paper, we present an approach for expressing and enforcing dataflow dependencies in data-centered software systems, and conclude with a validation of the approach in a servlet-based case study. Inspec keywords: object-oriented programming; software reliability; data flow analysis Subjects: Software engineering techniques; Object-oriented programming