14259461
Grid Unit: A Self-Managing Building Block for Grid System
Grid system software is inherently complex, hard to build and maintain. In this paper, we propose a self-managing building block: grid unit, which facilitates constructing grid system with higher availability and lower management overhead. We present an agent organization as autonomic management framework, and propose a self-recovering protocol to eliminate most of tough jobs from system administrator's routines. The system has been deployed on Dawning 4000A since 2004, the biggest node for China grid system. We have done extensive experiments to evaluate grid unit, and the collected log data shows the availability of a grid parallel process management service, built on the basis of grid unit, reaches 99.997%.
2643198
Easy and reliable cluster management: the self-management experience of Fire Phoenix
High-Performance clusters are rapidly becoming an important computing platform for both scientific and business applications. To fulfil the new demands and challenges, cluster system software is inevitably complex. Even for experienced administrators, the management of a cluster system is an exhausting job. This paper introduces Fire Phoenix, a scalable and self-managing cluster system software that supports both scientific and commercial applications. With the self-configuring and self-healing features, much of the machine configuration and error recovery can be done automatically. Our design has been proven effective in the operations of the Dawning 4000A supercomputer, which is the biggest cluster system in China
15192522
A layered design methodology of cluster system stack
The application range of cluster has expanded beyond scientific computing, but the present cluster system software fails to provide a flexible architecture to promote code reuse and facilitate building cluster system software for different computing contexts, most of which are developed from scratch case by case, or integrated or packaged with ldquothe best practicerdquo. In this paper, we have proposed a layered design methodology to build cluster system stack with different layers concentrating on different functions, and developed common sets of core service as reusing framework for different computing context. Following this methodology, we have built Phoenix-a complete cluster system stack for both scientific and business computing, which is verified and deployed on Dawning 4000 A super computer for scientific computing and other cluster systems for business computing. The qualitative evaluation and our practices show the design methodology of Phoenix has advantages over other methodologies.
368510
A Performance Model for Domino Mail Server
Using performance model to analyze the Internet service is prevailing. However, the research of the performance model for mail server retrains in the immature status. In this paper, based on the queue theory, we propose a performance model for Domino mail server. The verification and analysis of the model are also presented. The experimental results show that this model characterizes the behavior of Domino mail server well and prove that it is useful for the qualitative performance measurement of Domino mail server.
14894173
Gingko: correlating causal paths in distributed systems
Many large-scale systems are distributed systems of multiple communicating components. Finding causal paths of message traces between components throughout these systems is important to uncover runtime behaviors and identify the root cause of failures, but this "art" often hides in the heads of developers or domain experts. Our goal is to design tools and algorithms to help developers record this art into logs and help the modestly-skilled users and system administrators master it to make better use and management of distributed systems. In this paper, we present a methodology that automatically builds the causal paths of message traces by 1) an agreement with programmers on the style and content of logs produced by operational distributed systems they develop and 2) a correlation algorithm to build message causal paths with the clues from these logs. To validate this mechanism, we have implemented Gingko, a prototype providing a tool chain for users to gain better comprehensions of distributed systems and to debug them efficiently when errors happen.
14795008
The design methodology of Phoenix cluster system software stack
Though many research groups have explored the design methodology of cluster system software stack, few works discuss what constitutes a good one. In this paper, we choose four criteria throughout the lifecycle of cluster system software stack to evaluate its design methodology, including code reusability, evolveability, adaptability and manageability. According to the four criteria, we have proposed a management service-based layered design methodology and built a complete cluster system software stack for both scientific and business computing. Our practices and evaluations show our design methodology has advantages over others in terms of the proposed criteria.
32529879
Performance comparison of control schemes for ABR service in ATM LANs
The ATM Forum has defined a new service category, called the available bit rate service (ABR), which is intended for applications requiring tightly constrained cell loss but no bound on the delay or delay variation. Appropriate traffic control schemes are necessary for ABR service to achieve very low cell loss and maximize the network resource utilization by taking advantage of the available bandwidth remaining after CBR/VBR services have been supported. This paper compares the performance of a burst-level traffic control scheme and a rate-based feedback control scheme, through simulation in an ATM LAN environment. Our results indicate that the burst-level control scheme is more suitable for loss-sensitive but delay-insensitive applications such as ABR service, because it requires nearly zero buffers to achieve zero cell loss and potentially high network resource utilization, at the cost of an acceptable burst transfer delay.
95638
MU-MAQAS: A P2P based Model Updatable Mobile Automatic Q/A System
Along with the development of wireless technology and especially 3Gpsilas throw into commercial, the mobile value-added services gradually popular used, such as mobile automatic question and answer (Q/A) system. But the current mobile Q/A system mainly based on FAQ database, the question and answer can not be validated and updated by itself. So this paper attempts to implement a p2p based model updatable automatic Q/A system named MU-MAQAS for mobile phones using SMS interface. MU-MAQAS mainly includes: question & answer information collecting module and model manage & use module. It can automatically collect Q/A information from internet and update the Q/A model in time. A simulated Q/A system is also coded to validate the design. Results of simulation proved that under ideal conditions the systempsilas average responding time is less than 64 ms and precision is above 60% when there are no more than 3000 simultaneous asking queries, and so the completeness and feasibility of the systempsilas design is proved.
9419059
TLDFS: A Distributed File System based on the Layered Structure
This paper presents a novel distributed file system TLDFS, which consists of two layers. One is the block device layer, which makes the distributed file system manage the consistency of data easily by choosing an appropriate granularity of lock. We implement the distributed interfaces and the new data organization at the block level, which is different from most distributed file systems. The other is the file system layer that consists of three parts: interconnecting module, locking module and distributed file system module. Our prototype system proves the feasibility of the two-layered structure and the experiments show several advantages of TLDFS.
11142145
An Optimal Design Method for De-synchronous Circuit Based on Control Graph
De-synchronous is a very useful method to design asynchronous circuit automatically from synchronous description of circuits. This paper introduces an optimal design method based on Control Graph which is an abstract model of the de-synchronous circuit. The main purpose of this optimal design method is to reduce the extra overhead in the area of the de-synchronous circuit. The optimization algorithm takes the performance evaluation function based on the Control Graph of the de-synchronous circuit as its heuristic function. The performance evaluation function presented in this paper is a linear programming problem. In the end of this paper, the optimal method is applied to a set of benchmark circuits. The number of the local controllers in these circuits is markedly reduced by 54%, and the number of C-elements that is required to construct the handshake circuitry between local controllers is also reduced by 76.3%. So the entire area of the circuit is sharply reduced. Because this design method is directed by the performance evaluation function of the circuit, there is no penalty in performance of the de-synchronous circuit.
15406626
A Lightweight Sensor Network Management System Design
In this paper, we propose a lightweight and transparent management framework for TinyOS sensor networks, called L-SNMS, which minimizes the overhead of management functions, including memory usage overhead, network traffic overhead, and integration overhead. We accomplish this by making L-SNMS virtually transparent to other applications hence requiring minimal integration. The proposed L-SNMS framework has been successfully tested on various sensor node platforms, including TelosB, MICAz and IMote2.