Application of load balancing based on symmetric balanced incomplete block design to random networks

In a load balancing algorithm [O. Lee, M. Anshel, I. Chung, Design of an efficient load balancing algorithm on distributed networks by employing symmetric balanced incomplete block design, IEE Proceedings - Communications 151 (6) (2004) 535-538] based on the SBIBD (Symmetric Balanced Incomplete Block Design), each node receives global workload information by only two round message exchange with traffic overhead, where v is the number of nodes. It is very efficient and works well only when v=p²+p+1 is used for a prime number p. In this paper, we generated a special incidence structure using the SBIBD and then propose a new load balancing algorithm, which executes well for an arbitrary number of nodes. To accomplish this, we add a number of links to nodes in order for each node to receive more than 80% of the workload information by two round message exchange. For performance of our algorithm, we carried out an experiment for the number of nodes, w, which was up to 5000. Traffic overhead is less than in a round and standard deviation of traffic overhead shows that each node has a mostly well-balanced amount of traffic.     

One-dimensional partitioning for heterogeneous systems: Theory and practice

We study the problem of one-dimensional partitioning of nonuniform workload arrays, with optimal load balancing for heterogeneous systems. We look at two cases: chain-on-chain partitioning, where the order of the processors is specified, and chain partitioning, where processor permutation is allowed. We present polynomial time algorithms to solve the chain-on-chain partitioning problem optimally, while we prove that the chain partitioning problem is NP-complete. Our empirical studies show that our proposed exact algorithms produce substantially better results than heuristics, while solution times remain comparable.     

Optimal replica placement in hierarchical Data Grids with locality assurance

In this paper, we address three issues concerning data replica placement in hierarchical Data Grids that can be presented as tree structures. The first is how to ensure load balance among replicas. To achieve this, we propose a placement algorithm that finds the optimal locations for replicas so that their workload is balanced. The second issue is how to minimize the number of replicas. To solve this problem, we propose an algorithm that determines the minimum number of replicas required when the maximum workload capacity of each replica server is known. Finally, we address the issue of service quality by proposing a new model in which each request must be given a quality-of-service guarantee. We describe new algorithms that ensure both workload balance and quality of service simultaneously.     

Parallel and distributed simulation of sediment dynamics in shallow water using particle decomposition approach

This paper describes the parallel simulation of sediment dynamics in shallow water. By using a Lagrangian model, the problem is transformed to one in which a large number of independent particles must be tracked. This results in a technique that can be parallelised with high efficiency. We have developed a sediment transport model using three different sediment suspension methods. The first method uses a modified mean for the Poisson distribution function to determine the expected number of the suspended particles in each particular grid cell of the domain over all available processors. The second method determines the number of particles to suspend with the aid of the Poisson distribution function only in those grid cells which are assigned to that processor. The third method is based on the technique of using a synchronised pseudo-random-number generator to generate identical numbers of suspended particles in all valid grid cells for each processor. Parallel simulation experiments are performed in order to investigate the efficiency of these three methods. Also the parallel performance of the implementations is analysed. We conclude that the second method is the best method on distributed computing systems (e.g., a Beowulf cluster), whereas the third maintains the best load distribution.     

基于退火策略的分布式资源负载均衡算法

针对分布式资源导致的访问热点等一系列问题,建立了一个用于分布式资源退火的处理模型.根据该模型,提出了基于退火策略的分布式资源负载均衡算法;该算法通过访问分类、定向扩散等方法提高了系统性能.性能及试验分析表明,该算法能够减少系统内部通信量,抑制资源扩散的抖动现象等.     

大规模宽带接入及流量调度器的研究与实现

基于固定多出口链路网络,优化核心级数据处理方法,提出一种宽带网络接入及流量管理调度器系统架构模型,并设计了用户控制管理功能和客户端链路流量整形方法。实验表明,模型适用于多链路各种负载下的流量优化,有效解决了宽带网络的大量用户接入及负载均衡问题。     

基于历史信息的对等网络负载均衡算法

针对当前对等网络中存在的负载不均衡问题,提出了基于历史信息查询的负载均衡算法(HILBA),以提高系统的整体心?实验结果表明,此算法在节点同构和异构环境下都提高了系统的负载均衡能力.     

基于VRRP+MSTP协议的可靠性网络设计

针对现代企业对网络的可靠性需求,根据VRRP(Virtual Router Redundancy Protocol)和MSTP (Multiple Spaning Tree Protocol)协议理论,设计了一种方案使企业在访问网络中心数据时能实现路由冗余和负载均衡,在跨交换机同一子网内互访时也能够实现路由冗余和负载均衡,从而保证企业内关键业务的不间断运行,实现了网络的可靠性设计.     

模糊自整定PID的船舶蒸汽动力负荷控制

船舶蒸汽动力装置自动控制的首要任务是机组的负荷控制。传统的PID控制算法由于具有结构简单、易于实现、可消除静差等优点得到了广泛的应用,但它受控制对象的影响较大,只有在各参数整定良好的前提下才能得到满意的控制效果。根据上述情况,结合船舶蒸汽动力单元工况变化频繁的特点,提出一种基于输出响应的自适应PID算法,以提高控制系统适应负荷变化的能力。方法在保留传统定值PID控制算法优点的同时,引入模糊控制在线整定PID控制参数,改善了机组的负荷控制特性,具有一定的工程应用价值.     

一种结构化P2P网络动态负载均衡算法的研究

负载均衡是P2P网络的研究热点之一,当前负载均衡技术存在负载均衡程度低、假设条件过多等问题.提出一了种增强型负载均衡算法ELB_P2P,它根据节点的承栽能力为其分配相应大小的可动态调整的ID地址空间以及合理的载荷,在负载转移时自动选择延迟小带宽高的轻栽节点,并引入负载转移流量控制机制.实验表明,相对于Chord等传统P2P协议,ELB_P2P算法有更快的负载均衡速度、更小的负载均衡开销,系统稳定性好,在网络重栽情况下也能取得较低的负载不平衡度,并且对节点属性没有苛刻的限制和假定.