Model-driven performance evaluation for service engineering

Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Software quality aspects such as performance are of central importance for the integration of heterogeneous, distributed service-based systems. Empirical performance evaluation is a process of measuring and calculating performance metrics of the implemented software. We present an approach for the empirical, model-based performance evaluation of services and service compositions in the context of model-driven service engineering. Temporal databases theory is utilised for the empirical performance evaluation of model-driven developed service systems

A Monitoring Language for Run Time and Post-Mortem Behavior Analysis and Visualization

UFO is a new implementation of FORMAN, a declarative monitoring language, in which rules are compiled into execution monitors that run on a virtual machine supported by the Alamo monitor architecture.Comment: In M. Ronsse, K. De Bosschere (eds), proceedings of the Fifth International Workshop on Automated Debugging (AADEBUG 2003), September 2003, Ghent. cs.SE/030902

Run-Time Monitoring of Timing Constraints: A Survey of Methods and Tools

Abstract-Despite the availability of static analysis methods to achieve a correct-by-construction design for different systems in terms of timing behavior, violations of timing constraints can still occur at run-time due to different reasons. The aim of monitoring of system performance with respect to the timing constraints is to detect the violations of timing specifications, or to predict them based on the current system performance data. Considerable work has been dedicated to suggesting efficient performance monitoring approaches during the past years. This paper presents a survey and classification of those approaches in order to help researchers gain a better view over different methods and developments in monitoring of timing behavior of systems. Classifications of the mentioned approaches are given based on different items that are seen as important in developing a monitoring system, i.e., the use of additional hardware, the data collection approach, etc. Moreover, a description of how these different methods work is presented in this paper along with the advantages and downsides of each of them

Strong mutation testing strategies

Mutation Testing (or Mutation Analysis) is a source code testing technique which analyses code by altering code components. The output from the altered code is compared with output from the original code. If they are identical then Mutation Testing has been successful in discerning a weakness in either the test code or the test data. A mutation test therefore helps the tester to develop a program devoid of simple faults with a well developed test data set. The confidence in both program and data set is then increased. Mutation Analysis is resource intensive. It requires program copies, with one altered component, to be created and executed. Consequently, it has been used mainly by academics analysing small programs. This thesis describes an experiment to apply Mutation Analysis to larger, multi-function test programs. Mutations, alterations to the code, are induced using a sequence derived from the code control flow graph. The detection rate of live mutants, programs whose output match the original, was plotted and compared against data generated from the standard technique of mutating in statement order. This experiment was repeated for different code components such as relational operators, conditional statement or pointer references. A test was considered efficient if the majority of live mutants was detected early in the test sequence. The investigations demonstrated that control flow driven mutation could improve the efficiency of a test. However, the experiments also indicated that concentrations of live mutants of a few functions or statements could effect the efficiency of a test. This conclusion lead to the proposal that mutation testing should be directed towards functions or statements containing groupings of the code component that give rise to the live mutants. This effectively forms a test focused onto particular functions or statements

Dutch A-Scrambling Is Not Movement: Evidence from Antecedent Priming

The present study focuses on A-scrambling in Dutch, a local word-order alternation that typically signals the discourse-anaphoric status of the scrambled constituent. We use cross-modal priming to investigate whether an A-scrambled direct object gives rise to antecedent reactivation effects in the position where a movement theory would postulate a trace. Our results indicate that this is not the case, suggesting that A-scrambling in Dutch results from variation in base-generated order

Transformational maintenance by reuse of design histories

This thesis provides theory and procedures for modifying software artifacts implemented by a formal transformation process. Installing modifications requires knowing not only what transformations were applied (a derivation history) to construct the artifact, but also why the application sequence ensures that the artifact meets its specification. The derivation history and the justification are collectively called a design history. A Design Maintenance System (DMS), when provided with a formal change called a maintenance delta, revises a design history to guide construction of a new artifact. A DMS can be used to integrate a stream of deltas into a history, providing implementations as a side effect, leading to an incremental-evolution model for software construction.We provide a broadly applicable formal model of transformation systems in which specifications are performance predicates, subsuming the functional specifications which are traditional for transformation systems. Such performance predicates provide vocabulary used in the design history to describe the effect of applying sets of transformations.A nonprocedural, performance-goal-oriented Transformation Control Language (TCL) is defined to control navigation of the design space for a transformation system. Recording the execution of a TCL metaprogram directly provides a design history.A complete classification of, and representation for, the set of possible maintenance deltas is given in terms of the inputs defined by the transformation system model. Such deltas include not only specification changes, but also changes to implementation support technologies. Delta integration procedures for revising derivation histories given functional or support technology deltas are provided, based on rearranging the order of transformations in the design space. Building on these operations, integration procedures that revise the design history for each type of delta are described. An agenda-oriented TCL execution process dovetails smoothly with the integration procedures.Our DMS is compared to a number of other maintenance systems. By using an explicit delta and verified commutativity, our DMS often reuses transformations correctly when others fail

State-based testing - a new method for testing object-oriented programs

State-based testing is a new method for testing object-oriented programs. The information stored in the state of an object is of two kinds: control-information and data-storage. The control-information transitions are modelled as a finite state automaton. Every operation of the class under test is considered as a mapping from starting states to a finishing states dependent upon the parameters passed. The possible parameter values are analysed for significant values which combined with the invocation of an operation can be used to represent stimuli applied to an object under test. State-based testing validates the expected transformations that can occur within a class. Classes are modelled using physical values assigned to the attributes of the class. The range of physical values is reduced by the use of a technique based on equivalence partitioning. This approach has a number of advantages over the conceptual modelling of a class, in particular the ease of manipulation of physical values and the independence of each operation from the other operations provided by an object. The technique when used in conjunction with other techniques provides an adequate level of validation for object-oriented programs. A suite of prototype tools that automate the generation of state-based test cases are outlined. These tools are used in four case studies that are presented as an evaluation of the technique. The code coverage achieved with each case study is analysed for the factors that affect the effectiveness of the state-based test suite. Additionally, errors have been seeded into 2 of the classes to determine the effectiveness of the technique for detecting errors on paths that are executed by the test suite. 92.5% of the errors seeded were detected by the state-based test-suite