Optimizing construction of scheduled data flow graph for on-line testability

The objective of this work is to develop a new methodology for behavioural synthesis using a flow of synthesis, better suited to the scheduling of independent calculations and non-concurrent online testing. The traditional behavioural synthesis process can be defined as the compilation of an algorithmic specification into an architecture composed of a data path and a controller. This stream of synthesis generally involves scheduling, resource allocation, generation of the data path and controller synthesis. Experiments showed that optimization started at the high level synthesis improves the performance of the result, yet the current tools do not offer synthesis optimizations that from the RTL level. This justifies the development of an optimization methodology which takes effect from the behavioural specification and accompanying the synthesis process in its various stages. In this paper we propose the use of algebraic properties (commutativity, associativity and distributivity) to transform readable mathematical formulas of algorithmic specifications into mathematical formulas evaluated efficiently. This will effectively reduce the execution time of scheduling calculations and increase the possibilities of testability

Adapting a Stress Testing Framework to a Multi-module Security-oriented Spring Application

Programmeeritakse mitmekomponendilist süsteemi. Kolm põhikomponenti on järgmised: põhiserver (Spring rakendus), mobiilirakendused (iOS, Android), klienditeeninduse veebiportaalid. Kõige tähtsam süsteemi töös on põhiserver, kuna see on enamuse veebiportaalide ning mobiilirakenduste päringute sihtpunkt. See on mitmemooduliline projekt, kus kõik moodulid suhtlevad omavahel. Potentsiaalselt hakkab süsteemi kasutama sadu tuhandeid inimesi – kümneid tuhandeid paralleelseid sessioone. Seetõttu tuleb läbi viia süsteemi ulatuslik koormustestimine. Kahjuks on nii, et koormustestimise raamistikud oma originaalseisus ei sobi antud süsteemi testimiseks. Seega, koormustestimise raamistiku tuleb seadistada ning laiendada selleks, et see toetaks antud süsteemi spetsiifilisi protokolle ja võimaldaks testida kõiki komponente üheskoos. Hetkel on saadaval palju koormustestimise raamistikke. Mõned nendest on: Locust, Apache JMeter, Gatling Project. Need raamistikud erinevad üksteisest programmeerimiskeele, eriomaduste ning põhiloogika järgi. Kuna tegu on kommertsprojektiga, peab valitud koormustestimise raamistik vastama kliendi funktsionaalsete ja mittefunktsionaalsete nõuetele. Kuna koormustestimist viiakse läbi ainult põhiserveril, peab seadistama ja laiendama valitud raamistikku, et simuleerida teisi süsteemi komponente ja serveri protokolle. See töö annab kiire ülevaate varem mainitud koormustestimise raamistikest eriomaduste järgi, valib raamistiku, mida kohandatakse antud projekti raames koormustestimise läbi viimiseks ning kirjeldab kohandamise protsessi. Samuti toob see töö välja mõned koormustestimise raamistike piirangud ning kirjeldab meetodeid nende ületamiseks. Viimaks, süsteemi testitakse valitud raamistiku abil ning esitatakse ja valideeritakse tulemusi.A multi-component system is being build. Three main components are: backend server (Spring application), mobile applications (iOS, Android), customer service web portals. Our main concern is the backend server, because it is the destination of the majority of requests from customer service web portals and mobile applications. It is a multi-module project where all modules communicate to each other. The system is going to be used potentially by hundreds thousands of users with tens thousands of simultaneous usages. Therefore, extensive stress-testing must be conducted. Unfortunately, stress-testing frameworks in the original state are not suitable for the given system. Thus a stress-testing framework must be configured and extended to the point it supports the system’s specific protocols and can test all the system’s components together. There are numerous of stress-testing frameworks available. Some examples are: Locust, Apache JMeter, Gatling Project. These frameworks differ in terms of coding language, features and core logic. As it is a commercial project, the chosen stress-testing framework must also comply with client’s functional and non-functional requirements. Due to stress-testing being conducted only on the backend server component, the selected stress-testing framework must be configured/extended to simulate other components and the required server protocols. The thesis provides a brief comparison of the available stress-testing frameworks based on their features and written code language and define the one which is going to be adapted to conduct the stress-testing within the project and how the adaptation is done. The thesis also points out some of stress-testing frameworks’ limitations with techniques to overcome them. Finally, the system is tested using the selected testing framework and the results are presented and validated

Advanced Launch System Multi-Path Redundant Avionics Architecture Analysis and Characterization

The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28

Studies on Core-Based Testing of System-on-Chips Using Functional Bus and Network-on-Chip Interconnects

The tests of a complex system such as a microprocessor-based system-onchip (SoC) or a network-on-chip (NoC) are difficult and expensive. In this thesis, we propose three core-based test methods that reuse the existing functional interconnects-a flat bus, hierarchical buses of multiprocessor SoC's (MPSoC), and a N oC-in order to avoid the silicon area cost of a dedicated test access mechanism (TAM). However, the use of functional interconnects as functional TAM's introduces several new problems. During tests, the interconnects-including the bus arbitrator, the bus bridges, and the NoC routers-operate in the functional mode to transport the test stimuli and responses, while the core under tests (CUT) operate in the test mode. Second, the test data is transported to the CUT through the functional bus, and not directly to the test port. Therefore, special core test wrappers that can provide the necessary control signals required by the different functional interconnect are proposed. We developed two types of wrappers, one buffer-based wrapper for the bus-based systems and another pair of complementary wrappers for the NoCbased systems. Using the core test wrappers, we propose test scheduling schemes for the three functionally different types of interconnects. The test scheduling scheme for a flat bus is developed based on an efficient packet scheduling scheme that minimizes both the buffer sizes and the test time under a power constraint. The schedulingscheme is then extended to take advantage of the hierarchical bus architecture of the MPSoC systems. The third test scheduling scheme based on the bandwidth sharing is developed specifically for the NoC-based systems. The test scheduling is performed under the objective of co-optimizing the wrapper area cost and the resulting test application time using the two complementary NoC wrappers. For each of the proposed methodology for the three types of SoC architec .. ture, we conducted a thorough experimental evaluation in order to verify their effectiveness compared to other methods

Design of an integrated airframe/propulsion control system architecture

The design of an integrated airframe/propulsion control system architecture is described. The design is based on a prevalidation methodology that uses both reliability and performance. A detailed account is given for the testing associated with a subset of the architecture and concludes with general observations of applying the methodology to the architecture

AGOCS – Accurate Google Cloud Simulator Framework

This paper presents the Accurate Google Cloud Simulator (AGOCS) – a novel high-fidelity Cloud workload simulator based on parsing real workload traces, which can be conveniently used on a desktop machine for day-to-day research. Our simulation is based on real-world workload traces from a Google Cluster with 12.5K nodes, over a period of a calendar month. The framework is able to reveal very precise and detailed parameters of the executed jobs, tasks and nodes as well as to provide actual resource usage statistics. The system has been implemented in Scala language with focus on parallel execution and an easy-to-extend design concept. The paper presents the detailed structural framework for AGOCS and discusses our main design decisions, whilst also suggesting alternative and possibly performance enhancing future approaches. The framework is available via the Open Source GitHub repository

Cloud engineering is search based software engineering too

Many of the problems posed by the migration of computation to cloud platforms can be formulated and solved using techniques associated with Search Based Software Engineering (SBSE). Much of cloud software engineering involves problems of optimisation: performance, allocation, assignment and the dynamic balancing of resources to achieve pragmatic trade-offs between many competing technical and business objectives. SBSE is concerned with the application of computational search and optimisation to solve precisely these kinds of software engineering challenges. Interest in both cloud computing and SBSE has grown rapidly in the past five years, yet there has been little work on SBSE as a means of addressing cloud computing challenges. Like many computationally demanding activities, SBSE has the potential to benefit from the cloud; ‘SBSE in the cloud’. However, this paper focuses, instead, of the ways in which SBSE can benefit cloud computing. It thus develops the theme of ‘SBSE for the cloud’, formulating cloud computing challenges in ways that can be addressed using SBSE

Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 1: Army fault tolerant architecture overview

Digital computing systems needed for Army programs such as the Computer-Aided Low Altitude Helicopter Flight Program and the Armored Systems Modernization (ASM) vehicles may be characterized by high computational throughput and input/output bandwidth, hard real-time response, high reliability and availability, and maintainability, testability, and producibility requirements. In addition, such a system should be affordable to produce, procure, maintain, and upgrade. To address these needs, the Army Fault Tolerant Architecture (AFTA) is being designed and constructed under a three-year program comprised of a conceptual study, detailed design and fabrication, and demonstration and validation phases. Described here are the results of the conceptual study phase of the AFTA development. Given here is an introduction to the AFTA program, its objectives, and key elements of its technical approach. A format is designed for representing mission requirements in a manner suitable for first order AFTA sizing and analysis, followed by a discussion of the current state of mission requirements acquisition for the targeted Army missions. An overview is given of AFTA's architectural theory of operation

Development of a resource agent for an e-manufacturing system

Due to globalisation and distributed manufacturing systems the development and manufacture of products is no longer an isolated activity undertaken by either one discipline or a single organization but has become a global process. Using e-manufacturing companies can now outsource to manufacturers outside their geographical area and make them dependent on the production capabilities and responsiveness of the suppliers. Hence there is need for the suppliers to provide reliable information on the state of the orders being processed. E-manufacturing promises companies to exchange the required information with their suppliers by increased visibility to the shop floor and providing a platform for information interchange. The paper discusses the development of an e-manufacturing resource agent to enable manufactures to predict the probability of their outsourced machinery being available and the probability to complete an order without having a breakdown. The Maintenance Free Operation Period (MFOP) method is used to develop the agent. This means that the manufacturer will be expected to have a guarantee that no unscheduled maintenance activities will occur during each defined period of operation with the predefined level of confidence

On-board B-ISDN fast packet switching architectures. Phase 2: Development. Proof-of-concept architecture definition report

For the next-generation packet switched communications satellite system with onboard processing and spot-beam operation, a reliable onboard fast packet switch is essential to route packets from different uplink beams to different downlink beams. The rapid emergence of point-to-point services such as video distribution, and the large demand for video conference, distributed data processing, and network management makes the multicast function essential to a fast packet switch (FPS). The satellite's inherent broadcast features gives the satellite network an advantage over the terrestrial network in providing multicast services. This report evaluates alternate multicast FPS architectures for onboard baseband switching applications and selects a candidate for subsequent breadboard development. Architecture evaluation and selection will be based on the study performed in phase 1, 'Onboard B-ISDN Fast Packet Switching Architectures', and other switch architectures which have become commercially available as large scale integration (LSI) devices