消息队列中间件系统中消息队列与消息分发技术研究

从中间件的基本消息流入手，简单介绍了消息队列中间件中消息分发机制以及消息分发机制消息流过程。结合消息分发机制，讨论了队列式共享内存管理在中间件系统中的重要性。提出了消息队列中间件系统中消息分发器与消息队列的各种组合关系，描述了各种形式下的消息流过程，对每种方式作了详细分析和讨论，总结了各自的特点。最后，比较了它们对消息队列中间件效率、服务类型、消息优先级等的影响。     

基于JMS的消息队列中间件的研究与实现

消息队列中间件是采用基于消息传递机制和排队技术的进程间异步通讯机制,很好地解决了异构带来的一些通讯问题。目前消息中间件始终没有一个统一的标准,JMS是Sun公司提出的旨在统一各种MOM系统接口的规范,它包含点对点和发布／订阅两种消息模型,并提供可靠的消息传输、事务和消息过滤等机制。详细介绍了消息队列中间件的概念及用到的相关技术,并对JMS技术进行了深入的分析,在此基础上指出了设计基于JMS的消息队列中间件的重要意义。最后通过一个电子商务网中的实例,实现了JMS的应用。     

消息队列中间件在电力调度通信软件上的应用

论述了一种基于统一消息队列的中间件系统在电力调度通信软件上的应用。讨论了电力调度系统消息队列中间件的系统设计和系统实现、采用统一消息队列中间件软总线实现了电力调度自动化系统中多个应用子系统的集成。     

基于消息队列中间件的总线式工作流管理系统设计

探讨一种新的基于消息队列中间件的工作流管理系统，在消息队列中间件的支持下，工作流管理系统具有高的可靠性和稳定性、路由配置、松散耦合、事务及其安全支持、并发支持等优良的特性。理论与实验的结果表明，这种分布式工作流管理系统可以为电子商务应用提供新的解决方案。     

通信中间件的随机Petri网模型及性能分析

通信中间件由于其在屏蔽网络通信复杂性和提高系统性能等方面所起到的重要作用而被越来越广泛地应用。文章运用随机Petri网对通信中间件系统进行了描述,建立了一个实时通信中间件的同步及消息队列的模型。并对该模型的系统吞吐量、请求的平均延时等性能进行了评价,为系统的进一步设计和配置提供了理论依据。     

基于JMS的消息队列中间件的研究与实现

消息队列中间件是采用基于消息传递机制和排队技术的进程间异步通讯机制,很好地解决了异构带来的一些通讯问题.目前消息中间件始终没有一个统一的标准,JMS是Sun公司提出的旨在统一各种MOM系统接口的规范,它包含点对点和发布/订阅两种消息模型,并提供可靠的消息传输、事务和消息过滤等机制.详细介绍了消息队列中间件的概念及用到的相关技术,并对JMS技术进行了深入的分析,在此基础上指出了设计基于JMS的消息队列中间件的重要意义.最后通过一个电子商务网中的实例,实现了JMS的应用.     

消息队列中间件在高速公路收费系统中的设计与应用

从分析高速公路收费系统的特点和对消息队列中间件的要求入手,论述了基于UDP协议的消息队列中间件的可靠性,并提出了在高速公路收费系统下的解决方案。文中讨论了高速公路收费系统消息队列中间件的结构设计、消息传递设计和应用程序接口设计等关键技术,并提出了要用文件传输方式解决高速公路收费系统的大数据传送方案。     

电子商品交易系统中间件的设计及应用

针对分布式网络环境中电子商品交易的特点，采用TCP／IP机制、消息队列、身份论证，数字签名及加密等技术，研究实现了一种适合于实时商品交易系统的中间件，较好地满足了电子交易的实时性、可靠性、安全性等性能要求。本文讨论了该中间件的结构模型、工作机制及应用层协议。     

基于消息队列的总线式工作流模型

针对传统的中心式的引擎方面不足的问题,本文提出了基于消息队列中间件的跨系统总线式具有BPM和Workflow二级工作流流程架构能力的动态工作流模型.该工作流应用于实际的应用系统集成平台的开发,取得良好的效果.     

基于XML和Reactor模式的消息中间件的设计

在复杂的分布式计算环境中,中间件已经成为分布式计算应用的关键性部件。本文设计实现了一个基于消息队列的消息中间件系统,用于集成分布式应用,提供可靠的和松耦合的通信服务。系统采用XML定义消息,统一了消息格式;采用Reactor设计模式,提高了系统的模块化和可重用性。     

基于M/M/n/n+r排队模型的云计算中心服务性能分析

针对需要精确地评估分析云数据中心服务性能以保证服务质量(QoS)和避免违反服务水平协议(SLA)的问题,提出了一个基于M/M/n/n+r排队系统云计算中心近似分析模型。通过求解该模型获得用户请求响应时间的分布函数以及其他重要的QoS性能指标,同时通过仿真实验验证和获得服务器数量、队列缓冲区大小与响应时间、请求阻塞概率以及请求立即服务概率之间的关系。实验结果表明,提高服务器服务速率比增加服务器数量更利于提高服务性能。     

On the multi-server retrial queue with geometric loss and feedback: computational algorithm and parameter optimization

We consider an M/M/c retrial queue with geometric loss and feedback. An arriving customer finding a free server enters into service immediately; otherwise the customer either enters into an orbit to try again after a random amount of time or leave the system without service. After the completion of service, he decides either to join the retrial orbit or to leave the system. The retrial system is modelled by a quasi-birth-and-death process, and some system performance measures are derived. The useful formulae for computing the rate matrix and stationary probabilities are derived by means of matrix-analytical approach. A cost model is derived to determine the optimal values of the number of servers and service rate simultaneously at the minimal total expected cost per unit time. Illustrative numerical examples demonstrate the optimization approach as well as the effect of various parameters on system performance measures.     

基于随机响应队列的ActiveMQ安全应用

随着消息中间件在大型分布式系统中的广泛应用, 消息中间件应用的安全性需要得到足够重视. 文中分析了ActiveMQ传统共享响应队列应用模式中存在的安全隐患, 提出了一种基于随机响应队列的消息中间件应用模式. 在该应用模式中, 响应队列名称由客户端随机生成, 只有该客户端和服务端知道这个随机名称, 因此这个随机队列很隐蔽且只能被该客户端独享, 从而确保消息队列应用的安全性. 文中给出了该应用模式的基本框架、操作流程和安全性分析, 并运用理论计算的方法分析了该模式的运行性能. 结论表明, 在保证安全性的同时, 该应用模式不会影响系统的运行性能.     

Throughput in Processor-Sharing Queues

Processor-sharing queues are often used to model file transmission in networks. While sojourn time is a common performance metric in the queueing literature, average transmission rate is the more commonly discussed metric in the networking literature. Whereas much is known about sojourn times, there is little known about the average service rate experienced by jobs in processor-sharing queues. We first define the average rate as observed by users and by the queue. In an M/M/1 processor-sharing queue, we give closed-form expressions for these average rates, and prove a strict ordering amongst them. We prove that the queue service rate (in bps) is an increasing function of the minimum required average transmission rate, and give a closed-form expression for the marginal cost associated with such a performance requirement. We then consider the effect of using connection access control by modeling an M/M/1/K processor-sharing queue. We give closed-form expressions for average transmission rates, and discuss the relationship between the queue service rate (in bps), the queue limit, the average rate, and the blocking probability     

基于AMQP消息中间件的主动状态证书撤销机制实现

主动状态证书撤销机制是一种新的证书撤销验证机制,如何实现该机制还未见具体的案例。在分析高级消息队列协议(AMQP)的基础上,结合主动状态证书的订阅/发布要求,设计了一种基于AMQP消息中间件的主动状态证书发布与订阅模型。通过实验分析表明,该消息中间件系统应用灵活,系统性能高效、稳定。     

Violation Probability in Processor-Sharing Queues

Processor-sharing queues are often used to model file transmission in networks. While sojourn time is a common performance metric in the queueing literature, average transmission rate is the more commonly discussed metric in the networking literature. Whereas much is known about sojourn times, there is little known about the average service rate experienced by jobs in processor-sharing queues. We focus here upon performance requirements in the form of an upper bound on the probability of failing to achieve a specified minimum transmission rate or a specified minimum average rate. For an M/G/l processor-sharing queue, we give a closed-form expression for this violation probability. We derive closed-form expressions for the marginal service rate with respect to the violation probability and to the minimum transmission rate, and characterize when each is binding. We then consider the effect of using connection access control by modeling an M/G/l/K processor-sharing queue, and discuss the relationship between queue service rate, queue limit, violation probability, and blocking probability. Finally, we consider a two-class discriminatory processor-sharing queue, and discuss what combinations of class weighting and service rate can be used to achieve specified minimum rate violation probabilities for both classes.     

Information theoretic approximations for M/G/1 and G/G/1 queuing systems

Summary This paper presents new results concerning the use of information theoretic inference techniques in system modeling and concerning the widespread applicability of certain simple queuing theory formulas. For the case when an M/G/1 queue provides a reasonable system model but when information about the service time probability density is limited to knowledge of a few moments, entropy maximization and cross-entropy minimization are used to derive information theoretic approximations for various performance distributions such as queue length, waiting time, residence time, busy period, etc. Some of these approximations are shown to reduce to exact M/M/1 results when G = M. For the case when a G/G/1 queue provides a reasonable system model, but when information about the arrival and service distributions is limited to the average arrival and service rates, it is shown that various well known M/M/1 formulas are information theoretic approximations. These results not only provide a new method for approximating the performance distributions, but they help to explain the widespread applicability of the M/M/1 formulas.     

The analysis of the M/M/1 queue with two vacation policies (M/M/1/SWV+MV)

We consider an M/M/1 queue with two vacation policies which comprise single working vacation and multiple vacations, denoted by M/M/1/SMV+MV. Using two methods (called R-matrix method and G-matrix method), we obtain the stationary distribution of queue length (including the customer being in service) and make further analysis on the stationary numbers of customers in the working vacation and vacation period, respectively. The stochastic decomposition results of stationary queue length and the sojourn time of a customer are also derived. Meanwhile, we show that a simple and direct method of decomposition developed in Liu et al. [Stochastic decompositions in the M/M/1 queue with working vacations, Oper. Res. Lett. 35 (2007), pp. 595–600] is also applicable to our model. Furthermore, busy period is analysed by the limiting theorem of alternative renewal process. Finally, some boundary properties and numerical analysis on performance measures are presented.     

Analysis of a last come first served queueing system with customer abandonment

Motivated by manufacturing and service applications, we consider a single class multi-server queueing system working under the LCFS discipline of service. After entering the queue, a customer will wait a random length of time for service to begin. If service has not begun by this time she will abandon and be lost. For the GI/GI/s+M$\mathit{GI}/\mathit{GI}/s+M$ queue, we present some structural results to describe the relation between various performance measures and the scheduling policies. We next consider the LCFS M/M/s+M$M/M/s+M$ queue and focus on deriving new results for the virtual waiting time and the sojourn time in the queue (either before service or before abandonment). We provide an exact analysis using Laplace–Stieltjes transforms. We also conduct some numerical analysis to illustrate the impact of customer impatience and the discipline of service on performance.     

中间件技术在自来水营收系统中的应用

中间件是一种独立的系统软件或服务程序,分布式应用系统借助这种软件在不同的技术之间共享资源,管理计算资源和网络通讯。在应用系统中采用合适的中间件能够降低应用系统的复杂度,缩短开发周期。本文针对营收业务和银行联网收费的需求特点,分析中间件技术的应用,研究DataSnap应用服务器中间件和WebSphereMQ消息队列中间件...