With the significant advances in Information and Communications Technology (ICT) over the last half century, there is an increasingly perceived vision that computing will one day be the 5th utility (after water, electricity, gas, and telephony). This computing utility, like all other four existing utilities, will provide the basic level of computing service that is considered essential to meet the everyday needs of the general community. To deliver this vision, a number of computing paradigms have been proposed, of which the latest one is known as Cloud computing. Hence, in this paper, we define Cloud computing and provide the architecture for creating Clouds with market-oriented resource allocation by leveraging technologies such as Virtual Machines (VMs). We also provide insights on market-based resource management strategies that encompass both customer-driven service management and computational risk management to sustain Service Level Agreement (SLA)-oriented resource allocation. In addition, we reveal our early thoughts on interconnecting Clouds for dynamically creating global Cloud exchanges and markets. Then, we present some representative Cloud platforms, especially those developed in industries along with our current work towards realizing market-oriented resource allocation of Clouds as realized in Aneka enterprise Cloud technology. Furthermore, we highlight the difference between High Performance Computing (HPC) workload and Internet-based services workload. We also describe a meta-negotiation infrastructure to establish global Cloud

The Virtual Interface Architecture (VIA) is an industry standard user-level communication architecture for system area networks. The VIA provides a protected, directlyaccessible interface to a network hardware, removing the operating system from the critical communication path. In this paper, we design and implement a user-level Sockets layer over VIA, named SOVIA (Sockets Over VIA). Our objective is to use the SOVIA layer to accelerate the existing Sockets-based applications with a reasonable effort and to provide a portable and high performance communication library based on VIA to the application developers. SOVIA realizes comparable performance to native VIA, showing the minimum latency of 10.5�sec and the peak bandwidth of 814Mbps on Giganet’s cLAN. We have verified the functional compatibility with the existing Sockets API by porting FTP (File Transfer Protocol) and RPC (Remote Procedure Call) applications over the SOVIA layer. Compared to the Giganet’s LANE driver which emulates TCP/IP inside the kernel, SOVIA easily doubles the file transfer bandwidth in FTP and reduces the latency of calling an empty remote procedure by 77 % in RPC applications. 1.

In utility-driven cluster computing, cluster systems need to know the specific needs of different users so as to allocate resources according to their needs. They are also vital in supporting service-oriented Grid computing that harness resources distributed worldwide based on users' objectives. Market-based resource management systems make use of real-world market concepts and behavior to assign resources to users. This paper outlines a taxonomy that describes how market-based resource management systems can support utility-driven cluster computing. The taxonomy is used to survey existing market-based resource management systems to better understand how they can be utilized.

Users perceive varying levels of utility for each different job completed by the cluster. Therefore, there is a need for existing cluster resource management systems (RMS) to provide a means for the user to express its perceived utility during job submission. The cluster RMS can then obtain and consider these user-centric needs such as Qualityof-Service requirements in order to achieve utility-driven resource management and allocation. We advocate the use of computational economy for this purpose. In this paper, we describe an architectural framework for a utility-driven cluster RMS. We present a user-level job submission specification for soliciting user-centric information that is used by the cluster RMS for making better resource allocation decisions. In addition, we propose a dynamic pricing function

The simultaneous use of images obtained from different sources is common in medical diagnosis. However, even though the quality of these images has been improving, the integration of multimodality data into a unique 3D representation is still nontrivial. To overcome this problem, multimodal visualization techniques provide better insight by finding suitable strategies to integrate different characteristics of multiple data sets into a single visual representation. This paper describes a framework for interactive multimodal visualization of 3D medical images, focusing on the multimodal visualization model and the requirements and open issues for the development of such systems. A short overview of multimodal visualization systems and techniques is also presented.

This paper analyzes the performance of two parallel algorithms for solving the

Abstract. Application scheduling plays an important role in high-performance cluster computing. Application scheduling can be classified as job scheduling and task scheduling. This paper presents a survey on the software tools for the graphbased scheduling on cluster systems with the focus on task scheduling. The tasks of a parallel or distributed application can be properly scheduled onto multi-processors in order to optimize the performance of the program (e.g., execution time or resource utilization). In general, scheduling algorithms are designed based on the notion of task graph that represents the relationship of parallel tasks. The scheduling algorithms map the nodes of a graph to the processors in order to minimize overall execution time. Although many scheduling algorithms have been proposed in the literature, surprisingly not many practical tools can be found in practical use. After discussing the fundamental scheduling techniques, we propose a framework and taxonomy for the scheduling tools on clusters. Using this framework, the features of existing scheduling tools are analyzed and compared. We also discuss the important issues in improving the usability of the scheduling tools.

Most clusters so far have used WAN or LAN-based network products for communication due to their market availability. However, they do not always match communication patterns in clusters, thus incurring extra overhead. Based on our investigation for such overhead, we have optimized cluster communication at link layer. Partitioning each message in 16-byte packets, our optimization uses two techniques: (1) transferring in burst as many packets as the receiving buffer accepts at once, and (2) having each hardware component pass one packet to another in a pipelined manner. We have realized those two techniques in a link control hardware chip, referred to as MLC(Maestro Link Controller), and have constructed the Maestro cluster network using MLCs. This paper describes the feature of the Maestro cluster network and demonstrates the efficiency of our optimization techniques through performance experiments over this network. 1 Introduction The emergence of high-performance microprocessor has ...

AbstractÐThis paper proposes a Barrier Tree for Meshes (BTM) to minimize the barrier synchronization latency for two-dimensional (2D) meshes. The proposed BTM scheme has two distinguishing features. First, the synchronization tree is 4-ary. The synchronization latency of the BTM scheme is asymptotically …log 4 n†, while that of the fastest scheme reported in the literature is bounded between …log 3 n † and O…n 1=2 †, where n is the number of member nodes. Second, nonmember nodes are neither involved in the construction of a BTM nor actively participate in the synchronization operations, which avoids interference among different process groups during synchronization. This not only results in low setup overhead, but also reduces the synchronization latency. The low setup overhead is particularly effective for the dynamic process model provided in MPI-2. Extensive simulation study shows that, for up to 64 64 meshes, the BTM scheme results in about 40 70 percent shorter synchronization latency and is more scalable than conventional schemes. Index TermsÐBarrier synchronization, hardware-supported barriers, communication latency, wormhole routing, MPI. 1

In studying or designing parallel and distributed systems one should have available a robust analytical model that includes the major parameters that determines the system performance. Jackson networks have been very successful in modeling parallel and distributed systems. However, Jackson networks have their limitations. In particular, the product-form solution of Jackson networks assumes steady state and exponential service centers with certain specialized queueing discipline. In this paper, we present a performance model that can be used to study the transient behavior of parallel and distributed systems with finite workload. When the number of tasks to be executed is large enough, the model approaches the product-form of Jackson networks (steady state solution). We show how to use the model to analyze the performance of parallel and distributed systems. We also use the model to show to what extent the productform solution of Jackson networks can be used.