D2.4 Portable Testbed to Execute Virtualized NFV-based and SDN-based Scenarios

We evaluate the effects of guarded (or conditional, or predicated) execution on the performance of an instruction level parallel processor employing dynamic branch prediction. First, we assess the utility of guarded execution, both qualitatively and quantitatively, using a variety of application programs. Our assessment shows that guarded execution significantly increases the opportunities, for both compiler and dynamic hardware, to extract and exploit parallelism. However, existing methods of specifying guarded execution have several drawbacks that limit its use. Second, we study the interaction of guarded execution and dynamic branch prediction and show that the use of guarded execution significantly increases the number of instructions between mispredicted branches. Third, we propose a new method of specifying guarded execution. The proposed method uses special GUARD instructions, which can be used to incorporate guarded execution into existing instruction sets. GUARD instructions realize the full power of guarded execution, without the drawbacks of existing methods of specifying guarded execution.

Loops are the main source of parallelism in scientific programs. Hence, several techniques were developed to detect parallelism in these loops and transform them into parallel forms. In this dissertation, compile time transformations and efficient parallel execution of loops with various type of dependencies are investigated. First, Doacross loops with uniform dependencies are considered for execution on distributed memory parallel machines (multicomputers). Most known Doacross loop execution techniques can be applied efficiently only to shared memory parallel machines. In this thesis, code reordering technique, improvements to partitioning strategies, and finding a balance between communication and parallelism are presented to reduce the execution time of Doacross loops on multicomputers. As with most parallelizing transformation techniques, only single loopnests are considered in the first part of this dissertation. However, parallelizing each loopnest in a program separately, even if an optimal execution can be obtained for each loopnest, may not result in an efficient execution of all the code in the program because of communication overhead across the loops in a multicomputer environment. Hence, across loop data dependence representation and analysis are introduced in this work to improve the parallel execution of the whole code. Our contribution consists of finding and representing data dependencies whose sources and destinations are subspaces of the iteration space mainly common across the loops. This type of dependence information is used in this thesis to improve global iteration space partitioning, automatic generation of communication statements across loops, and index alignment. The final part of this dissertation presents new parallelizing techniques for loops with irregular and complex dependencies. Various data dependence analysis algorithms can be found in the literature even for loops with complex array indexing. However, the improvement in data dependence testing has not been followed by similar amelioration in restructuring transformations for loops with complex dependencies. Such loops are mostly executed in serial mode. Our parallelizing techniques for these loops consists of identifying regions of the iteration space where all iterations can be executed in parallel. The advantages of all the transformations presented in this dissertation are: (1) they significantly reduce the execution time of loops with various types of dependencies as shown in this work using the MasPar machine (2) they can be implemented at compile, time which makes the task of parallel programming easier.

The proliferation of service-oriented architectures in the last decade has brought forward an important class of sophisticated distributed applications that are founded on the idea of composing multiple simple services into a complex, coherent whole. Such applications spanning multiple service invocations can be most effectively realized by means of workflows. When it comes to high performance workflow execution, distribution (outscaling) of services is a key concept and also a very straightforward advantage of the workflow paradigm. Concretely, both the constituent services of the workflow and the system that manages their invocations have to be distributed across an environment of computational devices. In a wide spectrum of applications, that entail heterogeneity of the encompassed computational devices, e.g., modern emergency management, invocations of optimal service instances in conjunction to their reliability are fundamental prerequisites of distributed workflow management. At the center of this thesis is a formal model that defines the distributed (i.e., scalable) execution of workflows. To extend this model for reliability in a novel way, which does not affect the scalability of execution, the Safety-Ring system service is presented. The idea behind Safety-Ring is to offer recovery for a wide range of node failures, which host active services of running workflows. To this end, the Safety-Ring provides a scalable, reliable, and consistent data store that is used for the storage of workflow execution state. The novel failure-recovery mechanism features effective reliability such that can be applied on the nodes that host the Safety-Ring service themselves, thus we say the Safety-Ring is self-healing. To apply the reliable (and distributed) execution model, enhanced by Safety-Ring, to heterogeneous node environments, that are predominantly composed of mobile de- vices, this thesis presents the Compass data access protocol. In providing scalable data lookup for its maintained data, the Safety-Ring assumes network runtime characteristics which are rather stable, and thus Safety-Ring implicitly optimizes for the number of queried nodes. Especially in mobile applications, where node network connectivity dynamically changes, data access protocols should aim at reducing the overall data lookup latency, rather than the number of queried nodes. Compass introduces latency optimal paths to each node, which dynamically adapt to changing network characteristics. The scalable data lookup of Safety-Ring is not affected. In case distributed execution of workflows spans services of continuous (stateful) type, their reliability is decoupled from the Safety-Ring. Since such service types are predominantly featured by devices of limited resources, novel approaches to resource conservative recovery of failures for continuous services have to be provided. This thesis builds on proven recovery techniques, such as passive-standby, so as to enhance them for redundancy of the continuous state and thus improve the overall reliability of the system. In doing so the redundancy of state is enforced by means of a lightweight, in terms of network overhead, consistency protocol which allows for its application in resource limited node environments. In order to improve the execution performance of distributed workflows, in terms of throughput, this thesis offers a novel concept to services distribution. At the heart of our approach lie decentralized controllers that autonomously perform dynamic reconfiguration of the execution environment in terms of available services. This primarily affects the Safety-Ring service and all application services. Thereby, the goals of the controllers are to prevent workflow execution bottlenecks and unnecessary service deployments that waste resources. Since the controllers are equipped at any node in the system and can affect any other node of the system we say that the distributed workflow execution model is self-optimizing. Finally, all the presented concepts are implemented within the context of the OSIRIS distributed workflow engine and quantitatively evaluated in a series of experiments. The results of experiments confirm the benefits of our concepts for the distributed workflow execution model.

Dear SCPE Reader, We present a selection of papers which are extensions of papers presented at the 7-th International Symposium on Parallel and Distributed Computing, 1–5 July 2008, in Krakow, Poland. The motivation for publishing the selection in the SCPE Journal was, on the one hand, to present the flavour of the research reported at the conference and on the other hand to present some of the most relevant topics currently focused on the research on parallel and distributed computing in general. The selection contains only 6 papers out of about 60 presented at the conference, and thus, is far from covering all relevant topics represented at the ISPDC 2008. This is because not all of the invited authors were patient enough to accept a fairly long paper publishing process. Nevertheless, we hope that the presented papers will bring you closer to the research covered by the ISPDC conferences and will encourage you to participate in future ISPDC editions. The first paper ``The Impact of Workload Variability on Load Balancing Algorithms'' is by Marta Beltran and Antonio Guzman from King Juan Carlos University in Spain. It concerns an important topic of load balancing in cluster systems, namely adaptativity of the load balancing algorithms to changes of the workload in the system. Adequate accounting for additional load in the hosting system is of great relevance for correct optimization effects. The paper presents a thorough formal analysis of the workload variability metrics and their influence on the quality of load balancing algorithms. Four basic activities appearing in load balancing algorithms are identified, and based on them some algorithmic solutions are proposed to correctly deal with workload variability in system load balancing. The problem of dynamic load balancing algorithms robustness has been discussed. Two different robustness metrics sensitive to the applied type of opimization: local task-oriented or a global one enable selecting task remote execution or migration as load balancing operations. The proposed approach is illustrated with experiments. The second paper ``Model-Driven Engineering and Formal Validation of High-Performance Embedded Systems'' is by Abdoulaye Gamatie, Eric Rutten, Huafeng Yu, Pierre Boulet, Jean-Luc Dekeyser, from University of Lille and INRIA in France. The paper is concerned with a very advanced methodology of designing correct parallel embedded systems for intensive data-parallel computing. In their previous research, the authors of the paper designed the GASPARD embedded system design framework. It is based on the hardware/software co-design approach through model-driven engineering. The framework is based on an UML-like model specification language in which hardware and software elements are modelled using a component approach with special mechanisms for repetitive structures. This paper tries to combine the modelling framework of GASPARD with the mechanisms of synchronous languages to achieve design verifiability provided for such languages. The paper shows how GASPARD models can be translated into synchronous models based on data flow equations in order to formally check their correctness. The proposed approach is illustrated with an example of a video processing system. The third paper ``Relations Between Several Parallel Computational Models'' is by Stephan Bruda and Yuanqiao Zhang from Bishop’s University in Canada. The paper is concerned with theoretical aspects of shared memory systems described by the parallel random access machine PRAM model and aims in studying performance properties of different types of PRAM systems. The attention is focussed on analysing the computational power of two more sophisticated PRAM models (Combining CRCW and Broadcast Selective Reduction), which include data reduction in case of concurrent writes. The paper shows that these two models have equivalent computational power, which is a new result comparing the existing literature. The performance of both models applied to reconfigurable multiple bus machines was studied as a possible architectural solution for current VLSI processor implementations. It was shown that in such systems under reasonable assumptions concurrent-write does not enhance performance comparing the exclusive-write model. Another result important for the VLSI technology is that the Combining CRCW PRAM model (in which data of concurrent writes are arthmetically or logically combined before write) and the exclusive-write on directed reconfigurable busses perform in equivalent way under strong real-time requirements. The fourth paper ``Experiences with Mesh-Like Computations Using Prediction Binary Trees'' is by Gennaro Cordasco, Biagio Cosenza, Rosario de Chiara, Ugo Erra and Vittorio Scarano from the University ``degli Studi'' of Salerno and the University ``degli Studi della Biasilicata'' of Potenza in Italy. The paper concerns optimization methods for mesh-like computations in clusters of processors. The computations are perfomed assuming a phase-like program execution control using a tiling approach which reduces inter-processor communication. A temporal coherence is also assumed, which means that task sizes provide similar execution times in consecutive phases. Temporary coherent computations are structured in a Prediction Binary Tree, in which leaves represent computing tiles to be mapped to processors. A phase-by-phase semi-static load balancing is introduced to the scheduling algorithm. The scheduling algorithm is equipped with a predictor, which estimates the computation time of next phase tiles based on previous execution times and modifies the tiles to achieve balanced execution in phases. For this, two heuristics are used to leverage on data locality in processors. The proposed approach is illustrated by the example of interactive rendering with Parallel Ray Tracing algorithm. The fifth paper ``The Influence of the IBM pSeries Servers Virtualization Mechanism on Dynamic Resource Allocation in AIX 5L'' is by Maciej Mlynski from ASpartner Limited in Poland. The paper concerns a very up-to-date problem of system virtualization and presents the results of research carried on IBM pSeries servers. IBM is strongly developing the virtualization technique especially on IBM pSeries servers enabling an improved and flexible sharing of system resources between applications. The paper investigates novel facilities for dynamic resource management such as micro-partitioning and partition load manager. They enable dynamic creation of workload logical partitions of system resources and their dynamic mangement. It includes run-time resource re-alocation between logical partitions including setting of sharing specifications as well as run-time adding/removing/setting parameters of resources in the system. It remains an open question how to properly tune parameters of the operating system using the provided virtualization facilities to obtain the best efficiency for a given application program. The paper presents the results of experiments which study the effects of tuning the disk subsystem parameters under the IBM AIX 5L operating system with the use of the provided virtualization facilities on the resulting application execution performance. The results show that even small deterioration in the resource pool status requires an immediate adaptation of the operating system parameters to maintain the required performance. The sixth paper ``HeteroPBLAS: A Set of Parallel Basic Linear Algebra Subprograms Optimized for Heterogeneous Computational Clusters'' is by Ravi Reddy, Alexey Lastovetsky and Pedro Alonso from University College Dublin in Ireland and Polytechnic University of Valencia in Spain. The paper concerns the methodology for parallelization of linear algebra computations for execution in heterogeneous cluster environments. The design of the HeteroPBLAS library (Parallel Basic Linear Algebra Subprograms) for heterogeneous computational clusters is presented. The main contribution of the paper is the automation of the parallelization and optimization of the PBLAS, which is done by means of a special user interface and the underlying set of functions. An important element is here a performance model that is based on program code instrumentation, which determines parameters of the application and the executive heterogeneous platform relevant for execution performance of parallel code. The parameter values specified for or returned by execution of the performance model functions are next used for generation and optimal mapping of the parallel code of the library subroutines. The proposed approach is illustrated by experimental results of execution of optimized HeteroPBLAS programs on homogeneous and heterogeneous computing clusters. Marek Tudruj

Workflows are a technology to structure work in functional, non-overlapping steps. They define
\nnot only the order of execution of the steps, and describe whether steps are executed in
\nparallel, they also specify who or what tool has to fulfill which step. Workflows offer the possibility
\nto automate work, to increase the understandability of processes, and they ease the
\ncontrol of process execution. The tools to manage workflows, so called workflow management
\nsystems (WfMSs), are traditionally rigid as they separate workflow definition done at build time
\nfrom workflow execution done at run time. This makes them ill-suited for managing flexible and
\nunstructured workflows. In this thesis, we focus on the support of flexible processes in eHealth,
\nwhich are affected by more foreseen than unforeseen events. To bridge the gap between rigid
\nWfMSs and flexible workflows, we developed a concept for dynamic and context-aware workflow
\nmanagement called Flexwoman. Although our focus lies on flexible eHealth processes,
\nFlexwoman is a generic approach that can be applied to several different application domains.
\nFlexwoman supports the usage of context information to adapt processes automatically at run
\ntime to foreseen events. Processes can also be manually adapted to handle unforeseen events.
\nTo achieve this flexibility, context information from different sensors is unified and thus can be
\nanalyzed in the same way. The analysis and adaptation of workflows is executed with a rule engine.
\nA rule engine can store, reason about and apply knowledge automatically and efficiently.
\nRules and application logic are separated, thus, rules can be changed during run time without
\naffecting application logic or process description. Workflows are internally described by Hierarchical
\nColored Petri nets (HCPNs) and executed by a HCPN execution engine. HCPNs allow for
\na deterministic execution of workflows and can represent workflows on different levels of detail.
\nIn summary, in Flexwoman, significant context changes (events) trigger automated adaptations
\nthat replace parts of the workflow by sub workflows, which can in turn be adapted. The adaptations
\nand the rules for context-aware adaptation are saved in the organizational memory for
\nlater reuse. Flexwoman’s event based behavior facilitates proactive adaptations instead of only
\nallowing for adaptations while entering or leaving a task. Replacements are not bound to special
\nplaces defined at build time but each part of the workflow, which has not been executed yet, can
\nbe replaced at run time. We implemented and evaluated the concept. The evaluations show
\ni) that all required functionality is available, ii) that the system scales with a growing number of
\nrules, and iii) that the system correctly handles failure situations.

The paper sets out to investigate the difference between female and male managers in the context of strategy execution in their organizations with regard to the conceptual framework of leadership and performance. A survey questionnaire was administered to 322 managers to study the 5 dimensions regarding obstacles in strategy execution previously identified. The study primarily used principal component analysis (PCA) and then an analysis of variance (ANOVA) to examine the relationship between dimensions of strategy execution identified in previous research and also to assess empirical differences for socio-demographic variables such as personal and organizational perception of performance, number of years in the management position, number of workforce under supervision and number of years as an employee in the organization. The research found gender differences regarding strategy execution between men and women and confirmed the main hypothesis that there would be difference between men and women in matters of strategy execution. Additional work will be necessary to increase sample size and to specify sector of activity to generalize the findings. The study highlighted gender differences in terms of strategy execution and management practices. Key words: Gender management, strategy execution, women, organization, performance, leadership.

Java bytecodes can be executed with the following three methods: a Java interpreter running on a particular machine interprets bytecodes; a Just-in-Time (JIT) compiler translates bytecodes to the native primitives of the particular machine and the machine executes the translated codes; and a Java processor executes bytecodes directly. The first two methods require no special hardware support for the execution of Java bytecodes and are widely used currently. The last method requires an embedded Java processor, picoJavaI or picoJavaII for instance. The picoJavaI and picoJavaII are simple pipelined processors with no ILP (instruction level parallelism) and TLP (thread level parallelism) supports. A so-called MAJC (microprocessor architecture for Java computing) design can exploit ILP and TLP by using a modified VLIW (very long instruction word) architecture and vertical multithreading technique, but it has its own instruction set and cannot execute Java bytecodes directly. In this paper, we investigate a processor architecture which can directly execute Java bytecodes meanwhile can exploit Java ILP and TLP simultaneously. The proposed processor consists of multiple slots implementing horizontal multithreading and multiple functional units shared by all threads executed in parallel. Our architectural simulation results show that the Java processor could achieve an average 20 IPC (instructions per cycle), or 7.33 EIPC (effective IPC), with 8 slots and a 4-instruction scheduling window for each slot. We also check other configurations and give the utilization of functional units as well as the performance improvement with various kinds of working loads.

As observed from the reviewed literature, the execution of research and development (R and D) projects in Nigeria is challenged by many social, political and economic factors interacting in complex and dynamic ways. This interaction is reflected in the history of science and technology in Nigeria, its culture, legal systems, institutional frameworks and social capital. The economic and social development of Nigeria is critically dependent upon the ability to establish a competitive, productive and efficient industrial sector built on a strong technology base. This implies that her natural resources must be developed and utilised as inputs to industrial production and as direct products to improve the life of the population. Public research organisations (PROs) are considered to be critical to the survival of industries and to the achievement of self-reliance through the use of locally available raw materials. This thesis explores the application of strategic project management (SPM) practices in the execution of R and D projects in PROs in Nigeria. The research employed a mixed method of quantitative and qualitative research in order to capture the experiences of project management practitioners with SPM practices in PROs in Nigeria. Although areas of variations in practice were identified, the major findings highlighted that there was a gap in the practical implementation of SPM. The findings also revealed key determinants associated with the implementation of SPM and the factors that affected its application in PROs in Nigeria. The research findings were further synthesised into a framework, capturing ten key dimensions that must be taken into account in the execution of research and development projects. The determinants include having a project-based organisational structure, top management involvement in the project execution, strategic project leadership style, the appointment of a project team, the project team's competence, project alignment with organisational strategy, project prioritisation and selection, maximising R and D strategy, the project management process, and the SPM process. The framework validation was a follow-up discussion, which was conducted with project management practitioners in the selected research organisations in Nigeria. Reflecting on their experiences in the management of R and D projects, the participants acknowledged that the proposed SPM framework and its ten key variables were fundamental to the effective execution of R and D projects in PROs in Nigeria. It was concluded that the use of such a framework would highlight areas that needed to be addressed in order to achieve effective execution of R and D projects in these organisations.

This is the first of two essays about planning and execution with ill-defined and conflicting goals. The concept of flexecution - flexible execution - goes beyond simply adapting a plan as needed in order to reach our goals. Rather, flexecution entails changing the goals themselves based on discoveries made during execution. In pursuing ill-defined goals, we must expect to revise and even replace the goals we initially stated during the planning phase. One of my objectives in writing these essays is to describe the importance of goal discovery to planners and project managers who might not appreciate the difficulties posed by ill-defined goals. A second objective is to offer suggestions to computer scientists who design mixed- initiative systems about how to better support planning and execution with ill-defined goals. We'll begin with the notion of planning to set the stage for comparing planning using clear goals versus planning and execution using emergent goals.

Discrete Event System Specification DEVS separates modeling and simulation execution. Simulation execution is done within a runtime environment that is often called a DEVS simulator. This separation creates an opportunity to incorporate smart algorithms in the simulator to optimize simulation execution. In this paper, we propose incorporating some predictive machine learning algorithms into the DEVS simulator that can cut simulation execution times significantly for many simulation applications without compromising the simulation accuracy. In this paper, we introduce a specific learning mechanism that can be embedded into the DEVS simulator to incrementally build a predictive model that learns from past simulations. We further look into issues related to the predictive model selection, its prediction accuracy, its effect on the overall simulation performance, and when to switch between the predictive model and the simulation during an execution.

Facing the fast changing global competition environment, enterprises will not be able to survive if the ability of employee execution is not improved. It is essential for firms to dedicate to the development of human resource and raise the competitiveness. The employees’ reeducation and training program will be the key factor to develop employees’ potential abilities, and, therefore, enforce business growth in the future. A modernized organization should encourage employees to put into practice through learning orientation training transfer, and improve employee execution to create new competition advantage in the future. This study developed the measuring scale on employee’s execution and transfer climate with adequate content validity and reliability through literature analysis and expert consultation. Further, the study selected middle-level and top managers in service and financial industries as subject. After using stratified and purposive sampling, there were 136 effective questionnaires returned among 800 questionnaires distributed. The usable returned rate was 17%. The data were analyzed by a variety of statistical methods, such as canonical correlation analysis, pearson product-moment correlation analysis, regression analysis, hierarchical regression analysis, ANOVA and LISREL. After integrating the results of empirical analysis, the findings of the study are as follows: 1. Organizational leaning has significant positive correlation and effect on effectiveness of training transfer and employee’s execution; 2. Effectiveness of training transfer has significant positive correlation and effect on employee’s execution; 3. Effectiveness of training transfer shows significant intervening effects on the relationship between organizational leaning and employee’s execution; 4. Good model fitness of relationship exists among each construct; 5.Organizational leaning has significant positive effects on effectiveness of transfer of training with a moderating effect of transfer climate. Finally, this summary takes the deep discussion with the conclusions and management implications of this study and present the concrete contributions and suggestions to be references by the enterprises and the academia.

While a number of weak consistency mechanisms have been developed in recent years to improve performance and ensure availability in distributed, replicated systems, ensuring the correctness of transactional applications running on top of such systems remains a difficult and important problem. Serializability is a well-understood correctness criterion for transactional programs; understanding whether applications are serializable when executed in a weakly-consistent environment, however remains a challenging exercise. In this work, we combine a dependency graph-based characterization of serializability and leverage the framework of abstract executions to develop a fully-automated approach for statically finding bounded serializability violations under any weak consistency model. We reduce the problem of serializability to satisfiability of a formula in First-Order Logic (FOL), which allows us to harness the power of existing SMT solvers. We provide rules to automatically construct the FOL encoding from programs written in SQL (allowing loops and conditionals) and express consistency specifications as FOL formula. In addition to detecting bounded serializability violations, we also provide two orthogonal schemes to reason about unbounded executions by providing sufficient conditions (again, in the form of FOL formulae) whose satisfiability implies the absence of anomalies in any arbitrary execution. We have applied the proposed technique on TPC-C, a real-world database program with complex application logic, and were able to discover anomalies under Parallel Snapshot Isolation (PSI), and verify serializability for unbounded executions under Snapshot Isolation (SI), two consistency mechanisms substantially weaker than serializability.

This study aims to answer three main problems, namely: (1) How the provisions of the deadline for execution on the death row prisoners in the Indonesian justice system?; (2) What method of execution on death row prisoners in the Indonesian justice system?; and (3) How is the policy of capital punishment in Indonesia in the future?. This research uses the primary, secondary and tertiary legal materials. The research methods being used in this research is normative method with the application of the statute approach, the case approach and the comparative approach. The results of this study shows the following conclusions: (1) the criminal law system in Indonesia is not set the deadline for execution on death row prisoner who had obtained a court decision that is legally binding and or the clemency petition has been rejected signal by the president; (2) The method of execution that has been implemented in Indonesia is a method of firing squad the u.s. stipulated in Law No. 2/Pnps/1964; (3) The policy the SE for the death penalty law in Indonesia in the future will not be shifted away from the current state.

Some results on the complexity of exploiting data dependency in parallel logic programs

Scheduling task graphs under hard (end-to-end) timing constraints is an extensively studied NP-hard problem of critical importance for predictable software mapping on Multiprocessor System-on-chip (MPSoC) platforms. In this work we focus on an off-line (design-time) version of this problem, where the target task graph is known before execution time. We address the issue of scheduling robustness, i.e. providing hard guarantees that the schedule will meet the end-to-end deadline in presence of bounded variations of task execution times expressed as min-max intervals known at design time. We present a robust scheduling algorithm that proactively inserts sequencing constraints when they are needed to ensure that execution will have no inserted idle times and will meet the deadline for any possible combination of task execution times within the specified intervals. The algorithm is complete, i.e. it will return a feasible graph augmentation if one exists. Moreover, we provide an optimization version of the algorithm that can compute the shortest deadline that can be met in a robust way.