Scheduling multi‐component applications with mobile agents in heterogeneous distributed systems

In grid computing environment, several classes of multi‐component applications exist. These types of applications may often require additional resources of different types that go beyond what is available in any of the sites making up the grid resource composition. The heterogeneity nature of both the user application and the computing environment makes this a challenging problem. However, the current off‐the‐shelf scheduling software can hardly cope with these diversities in distributed computing application frameworks. Therefore, there is the need for an adequate scheduling system that would grant simultaneous or coordinated access to application of multi‐component nature that requires resources of possibly multiple types, in multiple locations, managed by different resource providers. The main focus of this paper is to develop a mobile agent scheduling model that addresses the aforementioned challenge. A scheduling policy that pertains to job scheduling and resource allocation is proposed. The scheduling policy treats different multi‐component applications requiring diverse heterogeneous resources fairly. The policy is used by mobile agents to schedule user applications and to also find available and suitable distributed resource that are capable of executing user application at a very minimal time. Copyright © 2015 John Wiley & Sons, Ltd.     

Use of run time predictions for automatic co-allocation of multi-cluster resources for iterative parallel applications

Metaschedulers co-allocate resources by requesting a fixed number of processors and usage time for each cluster. These static requests, defined by users, limit the initial scheduling and prevent rescheduling of applications to other resource sets. It is also difficult for users to estimate application execution times, especially on heterogeneous environments. To overcome these problems, metaschedulers can use performance predictions for automatic resource selection. This paper proposes a resource co-allocation technique with rescheduling support based on performance predictions for multi-cluster iterative parallel applications. Iterative applications have been used to solve a variety of problems in science and engineering, including large-scale computations based on the asynchronous model more recently. We performed experiments using an iterative parallel application, which consists of benchmark multiobjective problems, with both synchronous and asynchronous communication models on Grid’5000. The results show run time predictions with an average error of 7% and prevention of up to 35% and 57% of run time overestimations to support rescheduling for synchronous and asynchronous models, respectively. The performance predictions require no application source code access. One of the main findings is that as the asynchronous model masks communication and computation, it requires no network information to predict execution times. By using our co-allocation technique, metaschedulers become responsible for run time predictions, process mapping, and application rescheduling; releasing the user from these burden tasks.     

Maximizing quality of experience through context‐aware mobile application scheduling in cloudlet infrastructure

Application software execution requests, from mobile devices to cloud service providers, are often heterogeneous in terms of device, network, and application runtime contexts. These heterogeneous contexts include the remaining battery level of a mobile device, network signal strength it receives and quality‐of‐service (QoS) requirement of an application software submitted from that device. Scheduling such application software execution requests (from many mobile devices) on competent virtual machines to enhance user quality of experience (QoE) is a multi‐constrained optimization problem. However, existing solutions in the literature either address utility maximization problem for service providers or optimize the application QoS levels, bypassing device‐level and network‐level contextual information. In this paper, a multi‐objective nonlinear programming solution to the context‐aware application software scheduling problem has been developed, namely, QoE and context‐aware scheduling (QCASH) method, which minimizes the application execution times (i.e., maximizes the QoE) and maximizes the application execution success rate. To the best of our knowledge, QCASH is the first work in this domain that inscribes the optimal scheduling problem for mobile application software execution requests with three‐dimensional context parameters. In QCASH, the context priority of each application is measured by applying min–max normalization and multiple linear regression models on three context parameters—battery level, network signal strength, and application QoS. Experimental results, found from simulation runs on CloudSim toolkit, demonstrate that the QCASH outperforms the state‐of‐the‐art works well across the success rate, waiting time, and QoE. Copyright © 2016 John Wiley & Sons, Ltd.     

Design and analysis of target‐sensitive real‐time systems

A significant number of real‐time control applications include computational activities where the results have to be delivered at precise instants, rather than within a deadline. The performance of such systems significantly degrades if outputs are generated before or after the desired target time. This work presents a general methodology that can be used to design and analyze target‐sensitive applications in which the timing parameters of the computational activities are tightly coupled with the physical characteristics of the system to be controlled. For the sake of clarity, the proposed methodology is illustrated through a sample case study used to show how to derive and verify real‐time constraints from the mission requirements. Software implementation issues necessary to map the computational activities into tasks running on a real‐time kernel are also discussed to identify the kernel mechanisms necessary to enforce timing constraints and analyze the feasibility of the application. A set of experiments are finally presented with the purpose of validating the proposed methodology. Copyright © 2015 John Wiley & Sons, Ltd.     

COIVA: context‐aware and ontology‐powered information visualization architecture

This paper exploits semantics to apply context in run‐time adaptation, particularly for services in a user‐centered smart environment. Context‐sensitive services are usually focused on their own information without interoperation pretensions. It is necessary to enable common context models and systems in order to make context‐aware applications interoperable. Moreover, context management systems need to implement mechanisms to support the dynamic behavior of the users and their surroundings, including techniques to adapt the model to their future needs, to maintain the context information at run‐time and to be interoperable with external context models. By adapting web semantic technologies we can enable smarter and more proactive operation of context management systems. Copyright © 2010 John Wiley & Sons, Ltd.     

Cross‐layer resource control and scheduling for improving interactivity in Android

Android smartphones are often reported to suffer from sluggish user interactions due to poor interactivity. This is partly because Android and its task scheduler, the completely fair scheduler (CFS), may incur perceptibly long response time to user‐interactive tasks. Particularly, the Android framework cannot systemically favor user‐interactive tasks over other background tasks since it does not distinguish between them. Furthermore, user‐interactive tasks can suffer from high dispatch latency due to the non‐preemptive nature of CFS. To address these problems, this paper presents framework‐assisted task characterization and virtual time‐based CFS. The former is a cross‐layer resource control mechanism between the Android framework and the underlying Linux kernel. It identifies user‐interactive tasks at the framework‐level, by using the notion of a user‐interactive task chain. It then enables the kernel scheduler to selectively promote the priorities of worker tasks appearing in the task chain to reduce the preemption latency. The latter is a cross‐layer refinement of CFS in terms of interactivity. It allows a task to be preempted at every predefined period. It also adjusts the virtual runtimes of the identified user‐interactive tasks to ensure that they are always scheduled prior to the other tasks in the run‐queue when they wake up. As a result, the dispatch latency of a user‐interactive task is reduced to a small value. We have implemented our approach into Android 4.1.2 running with Linux kernel 3.0.31. Experimental results show that the response time of a user interaction is reduced by up to 77.35% while incurring only negligible overhead. Copyright © 2014 John Wiley & Sons, Ltd.     

Service selection and workflow mapping for Grids: an approach exploiting quality‐of‐service information

The advent of heterogeneous and distributed environments, such as Grid environments, made feasible the solution to computational‐intensive problems in a reliable and cost‐effective manner. In parallel, workflows with increased complexity that require specialized systems to deal with them are emerging, so as to carry out more composite and mission‐critical applications. In that rationale, quality‐of‐service (QoS) issues need to be tackled in order to ensure that each application satisfies the corresponding user requirements. Therefore, considering the quality provision aspect as fundamental for enabling Grid applications to become QoS compliant, we present an approach for service selection using QoS criteria. The latter is achieved with a suite of components that allow the different mappings of application workflow processes to Grid services that not only meet the user goals and requirements but also maximize his/her benefit in terms of the offered QoS level. We also demonstrate the operation of the aforementioned suite of components and evaluate its performance and effectiveness using a Grid scenario, based on a 3D image rendering application. Copyright © 2008 John Wiley & Sons, Ltd.     

Neural network‐based multi‐agent approach for scheduling in distributed systems

A distributed system consists of a collection of autonomous heterogeneous resources that provide resource sharing and a common platform for running parallel compute‐intensive applications. The different application characteristics combined with the heterogeneity and performance variations of the distributed system make it difficult to find the optimal set of needed resources. When deployed, user applications are usually handled by application domain experts or system administrators who depending on the infrastructure provide a scheduling strategy for selecting the best candidate resource over a set of available resources. However, the provided strategy is usually generic, aimed at handling a wide array of applications and does not take into consideration specific application resource requirements. As such, an intelligent method for selecting the best resources based on expert knowledge is needed. In this paper, we propose a neural network‐based multi‐agent resource selection technique capable of mimicking the services of an expert user. In addition, to cope with the geographical distribution of the underlying system, we employ a multi‐agent coordination mechanism. The proposed neural network‐based scheduling framework combined with the multi‐agent intelligence is a unique approach to efficiently deal with the resource selection problem. Results run on a simulated environment show the efficiency of our proposed method. Several scheduling simulations were conducted to compare the performance of some conventional resource selection methods against the proposed agent‐based neural network technique. The results obtained indicate that the agent‐based approach outperformed the classical algorithms by reducing the amount of time required to search for suitable resources irrespective of the resource size. Copyright © 2016 John Wiley & Sons, Ltd.     

A 2D–3D integrated tabletop environment for multi‐user collaboration

This paper proposes a novel tabletop display system for natural communication and flexible information sharing. The proposed system is specifically designed to integrate two‐dimensional (2D) and three‐dimensional (3D) user interfaces by using a multi‐user stereoscopic display, IllusionHole. The proposed system takes awareness into consideration and provides both 2D and 3D information and user interfaces. On the display, a number of standard Windows desktop environments are provided as personal workspaces, as well as a shared workspace with a dedicated graphical user interface. In the personal workspaces, users can simultaneously access existing applications and data, and exchange information between personal and shared workspaces. In this way, the proposed system can seamlessly integrate personal, shared, 2D, and 3D workspaces with conventional user interfaces and effectively support communication and information sharing. To demonstrate the capabilities of the proposed display system, a modeling application was implemented. A preliminary experiment confirmed the effectiveness of this system. Copyright © 2006 John Wiley & Sons, Ltd.     

A negotiation‐based method for task allocation with time constraints in open grid environments

This paper addresses the task allocation problem in an open, dynamic grid environments and service‐oriented environments. In such environments, both grid/service providers and consumers can be modelled as intelligent agents. These agents can leave and enter the environment freely at any time. Task allocation under time constraints becomes a challenging issue in such environments because it is difficult to apply a central controller during the allocation process due to the openness and dynamism of the environments. This paper proposes a negotiation‐based method for task allocation under time constraints in an open, dynamic grid environment, where both consumer and provider agents can freely enter or leave the environment. In this method, there is no central controller available, and agents negotiate with each other for task allocation based only on local views. The experimental results show that the proposed method can outperform the current methods in terms of the success rate of task allocation and the total profit obtained from the allocated tasks by agents under different time constraints. Copyright © 2014 John Wiley & Sons, Ltd.     

Guidelines for supporting real‐time multi‐touch applications

Multi‐touch driven user interfaces are becoming increasingly prevalent because of their intuitiveness and because of the reduction in the associated hardware costs. In recognition of this trend, multi‐touch software frameworks (MSFs) have begun to emerge. These frameworks abstract the low level issues of multi‐touch software development and deployment. MSFs therefore enable software developers who are unfamiliar with the complexities of multi‐touch software development to implement and deploy multi‐touch applications more easily. However, some multi‐touch applications have real‐time system requirements, and at present, no MSFs provide support for the development and deployment of such real‐time multi‐touch applications. The implication of this is that software developers are unable to take advantage of MSFs and, therefore, are forced to handle the complexities of multi‐touch and real‐time systems development and deployment for themselves in an ad hoc manner. The primary consequence of this is that the multi‐touch and/or real‐time aspects of the application may not function correctly. In this paper, guidelines are presented for applying real‐time system concepts to support the development and deployment of real‐time multi‐touch applications using MSFs. This serves to increase the probability that the application will meet its timing requirements while also reducing the complexity of the development and deployment process associated with multi‐touch applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Composing and scheduling service‐oriented applications in time‐triggered distributed real‐time Java environments

During the last decade, the number of distributed application domains with temporal requirements has significantly augmented, arising the necessity of exploring new concepts and paradigms that allow, on the one hand, the development of dynamic and flexible distributed applications and, on the other hand, the reusability of code. Service‐oriented paradigms have been successfully applied to distributed environments, increasing their flexibility and allowing the reusability of their components. Besides, distributed real‐time Java technologies have shown to be a good candidate to deploy real‐time distributed applications. This paper presents a model for service‐oriented applications on a time‐triggered distributed real‐time Java environment, focusing on the definition of the temporal model of an application and its schedulability, applying and evaluating this model in real‐time service‐oriented composition algorithms. Copyright © 2012 John Wiley & Sons, Ltd.     

Scalability limits of Bag-of-Tasks applications running on hierarchical platforms

Bag-of-Tasks applications are parallel applications composed of independent (i.e., embarrassingly parallel) tasks, which do not communicate with each other, may depend upon one or more input files, and can be executed in any order. Each file may be input for more than one task. Examples of Bag-of-Tasks (BoT) applications include Monte Carlo simulations, massive searches (such as key breaking), image manipulation applications and data mining algorithms. A common framework to execute BoT applications is the master-slave topology, in which the user machine is used to control the execution of tasks. In this scenario, a large number of concurrent tasks competing for resources (e.g., CPU and communication links) severely limits application execution scalability. This paper is devoted to study the scalability of BoT applications running on multi-node systems (such as clusters and multi-clusters) organized as hierarchical platforms, considering several communication paradigms. Our study employs a set of experiments that involves the simulation of various large-scale platforms. The results presented provide important guidelines for improving the scalability of practical applications.     

Java for high‐performance network‐based computing: a survey

There has been an increasing research interest in extending the use of Java towards high‐performance demanding applications such as scalable Web servers, distributed multimedia applications, and large‐scale scientific applications. However, extending Java to a multicomputer environment and improving the low performance of current Java implementations pose great challenges to both the systems developer and application designer. In this survey, we describe and classify 14 relevant proposals and environments that tackle Java's performance bottlenecks in order to make the language an effective option for high‐performance network‐based computing. We further survey significant performance issues while exposing the potential benefits and limitations of current solutions in such a way that a framework for future research efforts can be established. Most of the proposed solutions can be classified according to some combination of three basic parameters: the model adopted for inter‐process communication, language extensions, and the implementation strategy. In addition, where appropriate to each individual proposal, we examine other relevant issues, such as interoperability, portability, and garbage collection. Copyright © 2002 John Wiley & Sons, Ltd.     

Detection and analysis of resource usage anomalies in large distributed systems through multi‐scale visualization

Understanding the behavior of large scale distributed systems is generally extremely difficult as it requires to observe a very large number of components over very large time. Most analysis tools for distributed systems gather basic information such as individual processor or network utilization. Although scalable because of the data reduction techniques applied before the analysis, these tools are often insufficient to detect or fully understand anomalies in the dynamic behavior of resource utilization and their influence on the applications performance. In this paper, we propose a methodology for detecting resource usage anomalies in large scale distributed systems. The methodology relies on four functionalities: characterized trace collection, multi‐scale data aggregation, specifically tailored user interaction techniques, and visualization techniques. We show the efficiency of this approach through the analysis of simulations of the volunteer computing Berkeley Open Infrastructure for Network Computing architecture. Three scenarios are analyzed in this paper: analysis of the resource sharing mechanism, resource usage considering response time instead of throughput, and the evaluation of input file size on Berkeley Open Infrastructure for Network Computing architecture. The results show that our methodology enables to easily identify resource usage anomalies, such as unfair resource sharing, contention, moving network bottlenecks, and harmful short‐term resource sharing. Copyright © 2011 John Wiley & Sons, Ltd.     

Distributed Fixed‐Time Coordinated Tracking for Nonlinear Multi‐Agent Systems Under Directed Graphs

This paper is concerned with the fixed‐time coordinated tracking problem for a class of nonlinear multi‐agent systems under detail‐balanced directed communication graphs. Different from conventional finite‐time coordinated tracking strategies, the fixed‐time approach developed in this paper guarantees that a settling time bound is prescribed without dependence on initial states of agents. First, for the case of a single leader, a distributed protocol based on fixed‐time stability techniques is proposed for each follower to accomplish the consensus tracking in a fixed time. Second, in the presence of multiple leaders, a new distributed protocol is proposed such that states of followers converge to the dynamic convex hull spanned by those of leaders in a fixed time. In addition, for a class of linear multi‐agent systems, sufficient conditions that guarantee the fixed‐time coordinated tracking are provided. Finally, numerical simulations are given to demonstrate the effectiveness of the theoretical results.     

A distributed evolutionary approach for multisite mapping on grids

In this paper attention is concentrated on the mapping of computationally intensive multi‐task applications onto shared computational grids. This problem, already known to be as NP‐complete in parallel systems, becomes even more arduous in such environments. To find a near‐optimal mapping solution a parallel version of a Differential Evolution algorithm is presented and evaluated on different applications and operating conditions of the grid nodes. The purpose is to select for a given application the mapping solutions that minimize the greatest among the time intervals which each node dedicates to the execution of the tasks assigned to it. The experiments, effected with applications represented as task interaction graphs, demonstrate the ability of the evolutionary tool to perform multisite grid mapping, and show that the parallel approach is more effective than the sequential version both in enhancing the quality of the solution and in the time needed to get it. Copyright © 2011 John Wiley & Sons, Ltd.     

Single‐layered multi‐color electrowetting display by using ink‐jet‐printing technology and fluid‐motion prediction with simulation

Abstract— This paper describes a single‐layered multi‐color electrowetting display (EWD) by using ink‐jet‐printing (IJP) technology and comparing different pattern electrodes with the use of the numerical investigations of ANSYS FLUENT®. This work consists of two parts: the first describes the design of implementing a single‐layered multi‐color EWD and the second demonstrates the application of ANSYS FLUENT® simulation in different pattern electrodes settings on the proposed EWD. The single‐layered multi‐color EW device was evaluated by using various colored oils without adopting a color filter. The single‐layered multi‐color EWD at a driving voltage of 25 V can achieve a maximum aperture ratio and reflectivity of 80% and 38.5%, respectively. The colored saturation of R, G, B oils can increase to 50% (NTSC: 13.3–27.8%). In addition, a radiate electrode at the required viewable area condition of 85% and force 5 * F^k, which results in ink stable contraction and a shorter response time of 50% (radiate vs. square), was proposed. The experimental results and simulation demonstrate that ink‐jet‐printing (IJP) technology along with the use of radiate electrodes can result in a single‐layered multi‐color EWD with a shorter response time.