1954273
An architecture for building reliable distributed object-based systems
This paper proposes an architecture for designing fault-tolerant distributed object systems. The proposed architecture attempts to bring advances in client-server, remote procedure call, reliable group communication, and object orientation technologies under a unified architecture to ease application developers' work of building reliable distributed systems. The resulting application systems should be enhanced with modularity and flexibility.
17339667
The design and implementation of an active replication scheme for distributing services in a cluster of workstations
Replication is the key to providing high availability, fault tolerance, and enhanced performance in a cluster of workstations (COWs). However, building such a system remains as a difficult and challenging task, mainly due to the difficulty of maintaining data consistency among replicas and the lack of easy and efficient tools supporting the development procedure. In this paper we propose an active replication scheme in which data consistency can be maintained. Based on the active replication scheme, we present an object-oriented design pattern and a constructing tool to simplify the design and implementation of service replications in COWs.
2813000
Detecting and tolerating failures in a loosely integrated heterogeneous database system
This article presents the design and prototype implementation of a fault detection and fault tolerance facility based on the reactive system model for a loosely integrated heterogeneous database system running on a network of workstations. The database system consists of a number of fully autonomous databases that, through their willingness, can share some portion of their information. Sensors (functions that expose some part of the state of an object) are placed on individual databases and system objects (such as traders, agents, and other sensors). Other databases and system objects, and applications can subscribe to a sensor and therefore are notified whenever the sensor value changes. The fault detection mechanism uses sensors to monitor individual databases and system objects and to detect database or system faults. The fault tolerance mechanism uses actuators (functions that can change the state of an object) to react on database or system faults.
12866276
A Load Balancing Algorithm for Web Based Server Grids
Load balance is a critical issue in distributed systems, such as server grids. In this paper, we propose a Balanced Load Queue (BLQ) model, which combines the queuing theory and hydro-dynamic theory, to model load balance in server grids. Base on the BLQ model, we claim that if the system is in the state of global fairness, then the performance of the whole system is the best. We propose a load balanced algorithm based on the model: the algorithm tries its best to keep the system in the global fairness status using job deviation. We present three strategies: best node, best neighbour, and random selection, for job deviation. A number of experiments are conducted for the comparison of the three strategies, and the results show that the best neighbour strategy is the best among the proposed strategies. Furthermore, the proposed algorithm with best neighbour strategy is better than the traditional round robin algorithm in term of processing delay, and the proposed algorithm needs very limited system information and is robust.
37909904
An Efficient Reliable Architecture for Application Layer Anycast Service
Anycast is a new service in IPv6, and there are some open issues about the anycast service. In this paper, we focus on efficient and reliable aspects of application layer anycast. We apply the requirement based probing routing algorithm to replace the previous period based probing routingalgorithm for anycast resolvers. We employ the twin server model among the anycast servers, therefore, try to present a reliable service in the Internet environment. Our theoretical analysis shows that the proposed architecture works well, and it offers a more efficient routing performance and fault tolerance capability.
19007096
A Self-Learning System for Identifying Harmful Network Information
Network information identification is a “hot” topic currently. This paper designs a self-learning system using neural network algorithm for identifying the harmful network messages of both Chinese and English languages. The system segments the message into words and creates key word vector which characterizes the harmful network information. The BP algorithm is taken advantage of to train the neural network. The result of training and studying of the neural network can be applied onto many network applications based on message identification. The result of experiments demonstrates that our system has a high degree of accuracy.
15855140
A reactive system architecture for building fault-tolerant distributed applications
Most fault-tolerant application programs cannot cope with constant changes in their environments and user requirements because they embed policies and mechanisms together so that if the policies or mechanisms are changed the whole programs have to be changed as well. This paper presents a reactive system approach to overcoming this limitation. The reactive system concepts are an attractive paradigm for system design, development and maintenance because they separate policies from mechanisms. In the paper we propose a generic reactive system architecture and use group communication primitives to model it. We then implement it as a generic pack age which can be applied in any distributed applications. The system performance shows that it can be used in a distributed environment effectively.