Extensively class tested, this text takes an innovative approach to explaining the process of software testing: it defines testing as the process of applying a few well-defined, general-purpose test criteria to a structure or model of the software. The structure of the text directly reflects the pedagogical approach and incorporates the latest innovations in testing, including techniques to test modern types of software such as OO, web applications, and embedded software.

Introduction to Software Testing: List of Figures

Will Tracz, our esteemed editor and Used-Program salesman, has written an entertaining, non-technical book dealing with the practice (and lack of) of software reuse. Its a collection of essays, mostly rehashed (reused?) and updated from various columns and papers published over the years.. Its a short (a bit over 200 pages) easy reading and enjoyable book (I read most of it in one sitting). Some of the essays discuss what was printed in the past and a discussion of the current status of the points.

Safeware: System Safety and Computers

Assurance requirements were included in the disposal regulations to compensate in a qualitative manner for the inherent uncertainties in projecting the behavior of natural and engineered components of the WIPP for many thousands of years (50 FR 38072). Section 194.42 is one of the six assurance requirements in the Compliance Criteria. Section 194.42 specifically addresses requirements for monitoring the disposal system during preand post-closure operations. This requirement distinguishes between preand post-closure monitoring because of the differences in monitoring techniques used to access the repository during operations (pre­ closure) and after the repository has been backfilled and sealed (post-closure). The purpose of monitoring is to confirm that the repository is behaving as predicted.

https://repository.kallipos.gr/bitstream/11419/859/1/02_chapter_A1.pdf

Monitoring στη ΜΕΘ

All Access to FAILURE MODE AND EFFECTS ANALYSIS FMEA PDF. Free Download FAILURE MODE AND EFFECTS ANALYSIS FMEA PDF or Read FAILURE MODE AND EFFECTS ANALYSIS FMEA PDF on The Most Popular Online PDFLAB. Only Register an Account to DownloadFAILURE MODE AND EFFECTS ANALYSIS FMEA PDF. Online PDF Related to FAILURE MODE AND EFFECTS ANALYSIS FMEA . Get Access FAILURE MODE AND EFFECTS ANALYSIS FMEA PDF and Download FAILURE MODE AND EFFECTS ANALYSIS FMEA PDF for Free.

Failure Mode and Effects Analysis (FMEA)

We have developed a new replay debugging tool, liblog, for distributed C/C++ applications. It logs the execution of deployed application processes and replays them deterministically, faithfully reproducing race conditions and non-deterministic failures, enabling careful offline analysis.

To our knowledge, liblog is the first replay tool to address the requirements of large distributed systems: lightweight support for long-running programs, consistent replay of arbitrary subsets of application nodes, and operation in a mixed environment of logging and nonlogging processes. In addition, it requires no special hardware or kernel patches, supports unmodified application executables, and integrates GDB into the replay mechanism for simultaneous source-level debugging of multiple processes.

This paper presents liblog's design, an evaluation of its runtime overhead, and a discussion of our experience with the tool to date.

/pdf/replay-debugging-for-distributed-applications-1xrmklny2h.pdf

Replay debugging for distributed applications


Testing is an important part of any software development project, and can typically surpass more than half of the development cost. For safety-critical computer based systems, testing is ...

/pdf/monitoring-testing-and-debugging-of-distributed-real-time-1l8okt1pq5.pdf

Monitoring, Testing and Debugging of Distributed Real-Time Systems

In this paper we present a new approach to deterministic replay using standard components. Our method facilitates cyclic debugging of real-time systems with industry standard real-time operating systems using industry standard debuggers. The method is based on a number of new techniques: A new marker for deterministic differentiation between e.g., loop iterations for deterministic reproduction of interrupts and task preemptions, an algorithm for finding well-defined starting points of replay sessions, as well as a technique for using conditional breakpoints in standard debuggers to replay the target system. We also propose and discuss different methods for deterministic monitoring, and provide benchmarking results from an industrial strength case study demonstrating the feasibility of our method. Previously published solutions to the problem of debugging real-time systems have been based on the concept of deterministic replay: where significant system events like task-switches of multitasking software and external inputs are recorded during run-time, and later replayed (re-executed) off-line. Previous works have been based on either non-standard hardware, specially designed compilers or modified real-time operating systems. The reliance on non-standard components has limited the success of the approach. Even though this idea has been around for 20 years, no industrial application for debugging of real-time systems of the method has been presented.

Replay debugging of real-time systems using time machines

Cyclic debugging is one of the most important and most commonly used activities in program development. During cyclic debugging, a program is repeatedly re-executed to track down errors when a failure has been observed. This process necessitates reproducible program executions. Applying classical debugging techniques, such as using breakpoints or single stepping, in real-time systems changes the temporal behaviour and makes reproduction of the observed failure during debugging less likely, if not impossible. Consequently, these techniques are not directly applicable to the cyclic debugging of real-time systems. In this paper, we present a novel software-based approach for the cyclic debugging of distributed real-time systems. By the online recording of significant system events, and then deterministically replaying them off-line, we can inspect a real-time system in great detail, while still preserving its real-time behaviour.

Using deterministic replay for debugging of distributed real-time systems

Execution time analysis is used in the development of real time and embedded systems to derive the timing estimates required for schedulability analysis. The execution time of the analyzed program is typically obtained by combining results from program flow analysis (such as number of iterations in loops) with low level timing information. The paper proposes a method for low level timing analysis based on measurements of execution times of programs executing on the actual target architecture. The essence of the method is to derive a system of linear equations from a limited number of timing measurements of an instrumented version of the considered program. The solution to these equations give execution times for program fragments, from which execution time measures for the entire program can be derived. The main advantage with this approach is that architectural modeling is not needed, hence the risk of a discrepancy between model and real system is avoided. Also, compared to the non-exhaustive measurements performed in industry today, our approach is more structured and gives complete coverage in terms of the program paths considered. We present our method in the context of a simple, but reasonably realistic processor model and show how it can be extended to architectures with pipelines.

Using measurements to derive the worst-case execution time

Reproducible and deterministic testing of sequential programs can in most cases be achieved by controlling the sequence of inputs to the program. The behavior of a distributed real-time system, on the other hand not only depends on the inputs but also on the order and timing of the concurrent tasks that execute and communicate with each other and the environment. Hence, sequential test techniques are not directly applicable, since they disregard the significance of order and timing of the tasks. In this paper we present a method for identifying all possible orderings of task starts, preemptions and completions for tasks executing in a distributed real-time system. Together with an accompanying testing strategy, this method allows test methods for sequential programs to be applied, since each identified ordering can be regarded as a sequential program. In the presented analysis and testing strategy, we consider task sets with recurring release patterns, and take into account the effects of clock synchronization and variations in start and execution times of the involved tasks.

/pdf/towards-systematic-testing-of-distributed-real-time-systems-ups9nisu9s.pdf

Henrik Thane

Papers

Monitoring, Testing and Debugging of Distributed Real-Time Systems

Replay debugging of real-time systems using time machines

Using deterministic replay for debugging of distributed real-time systems

Using measurements to derive the worst-case execution time

Towards systematic testing of distributed real-time systems