Evaluation of Program Code Caching for Mobile Agent Migrations

Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system.     

Mobile agent-enabled framework for structuring and building distributed systems on the internet

Mobile agent has shown its promise as a powerful means to complement and enhance existing technology in various application areas. In particular, existing work has demonstrated that MA can simplify the development and improve the performance of certain classes of distributed applications, especially for those running on a wide-area, heterogeneous, and dynamic networking environment like the Internet. In our previous work, we extended the application of MA to the design of distributed control functions, which require the maintenance of logical relationship among and/or coordination of proc- essing entities in a distributed system. A novel framework is presented for structuring and building distributed systems, which use cooperating mobile agents as an aid to carry out coordination and cooperation tasks in distributed systems. The framework has been used for designing various distributed control functions such as load balancing and mutual ex- clusion in our previous work. In this paper, we use the framework to propose a novel ap- proach to detecting deadlocks in distributed system by using mobile agents, which dem- onstrates the advantage of being adaptive and flexible of mobile agents. We first describe the MAEDD (Mobile Agent Enabled Deadlock Detection) scheme, in which mobile agents are dispatched to collect and analyze deadlock information distributed across the network sites and, based on the analysis, to detect and resolve deadlocks. Then the design of an adaptive hybrid algorithm derived from the framework is presented. The algorithm can dynamically adapt itself to the changes in system state by using different deadlock detec- tion strategies. The performance of the proposed algorithm has been evaluated using simulations. The results show that the algorithm can outperform existing algorithms that use a fixed deadlock detection strategy.     

分布交互仿真中基于

Distributed interactive simulation requires high network bandwidth and computation capacity which caused by redundant data when the system’s scale increases. This situation can be alleviated by data filtering to great extent. But the effective filtering scheme requires simulation hosts receiving accurate filtering information and high processing capability, this consumes too much computation resources when systems grow. In this paper, the authors propose a server-based hierarchical filtering scheme. New scheme frees the simulation hosts from the filtering processing and avails system’s scalability. New scheme also exploits the potential locality of distributed interactive simulation, which reduces the amounts of filtering messages exchanged and filtering computation.     

A New Approach for Automation of Distributed Systems

The concept Lean Web Automation (LWA) describes a new approach for web-based operation of automation devices in distributed systems, which can be used flexible by means of compact and low-cost software without installation expense on the client side. A dynamic process data transfer in the TCP/IP network is implemented by a javabased application model. This model uses a process data proxy to create at web clients an interface to process data of a remote automation device. A first practical …     

设备网网络在自动化系统中的应用

This paper deals with the structure and the merit of DeViceNet.It deacribes the process and interface of the network communication in details.DeviceNet is derived from CAN protocol, it saves field wirse by using BUS structure, and reduces the network traffic by using the model of Producer/Consumer.DeviceNet can provide the ability of collecting monitor data and configuration data hrom the devieces without interrupting their communication.Rockwell Automation interproses a DeviceNet Scanner between PLC controller and the network to manage the exchange of data,and also introduces a communication interface to allow lots of devices to connect to DeviceNet.Based on DeviceNet.Rockwell Automation advanced a network system in plant with three layers:DeviceNet,ControlNet and EtherNet.     

Active network supports for mobile IP

The basic mobile IP protocol is difficult to implement on the traditional IP network and not flexible and efficient under certain conditions.For example,firewalls or boundary routers may drop packets sent by mobile nodes for security reasons.Traditional networking devices such as routers cannot dynamically load and unload extended services to achieve different qualities of services.In this paper,a new scheme of using the active network to support the mobile IP is presented.The Softnet,a prototype of active networks based on mobile agents,is introduced.The active network is characterized by the programmability of its intermediate nodes and therefore presents dynaic and flexible behaviors.Special services can be dynamically deployed onto the active nodes in the Softnet.This property is definitely required in implementing the mobile IP protocols.The SOftnet.This property is definitely required in implementing the mobile IP protocols.The Softnet.This property is definitely required in implementing the mobile IP protocols.The Softnet supports not only the basic mobile IP protocol but also other extended mobile IP protocols.Virtual networks for mobile IP services are dynamically formed by mobile agents in the Softnet to provide different qualities of services.     

Comparing K-Means and Mean Shift Algorithms Performance Using Mahout in a Private Cloud Environment

Cloud computing has providing the possibility of services like store data, run applications and scalability of resources. The ability to measure computing resources according to request allows a great quantity of data to be stored in Data Kernels. Hadoop is a promising solution to solve problems with big sets of data. Mahout is a project developed with Hadoop that, by default, implements several grouping and classification algorithms, such as K-Means and Mean Shift, which are grouping algorithms successfully used during the last years in small databases. This paper presents a performance analysis of K-Means and Mean Shift in a standard implementation of Mahout in MapReduce distributed paradigm.     

Massive Storage Systems

To accommodate the explosively increasing amount of data in many areas such as scientific computing and e-Business, physical storage devices and control components have been separated from traditional computing systems to become a scalable, intelligent storage subsystem that, when appropriately designed, should provide transparent storage interface, effective data allocation, flexible and efficient storage management, and other impressive features. The design goals and desirable features of such a storage subsystem include high performance, high scalability, high availability, high reliability and high security. Extensive research has been conducted in this field by researchers all over the world, yet many issues still remain open and challenging. This paper studies five different online massive storage systems and one offline storage system that we have developed with the research grant support from China. The storage pool with multiple network-attached RAIDs avoids expensive store-and-forward data copying between the server and storage system, improving data transfer rate by a factor of 2-3 over a traditional disk array. Two types of high performance distributed storage systems for local-area network storage are introduced in the paper. One of them is the Virtual Interface Storage Architecture (VISA) where VI as a communication protocol replaces the TCP/IP protocol in the system. VISA's performance is shown to achieve better than that of IP SAN by designing and implementing the vSCSI (Vl-attached SCSI) protocol to support SCSI commands in the VI network. The other is a fault-tolerant parallel virtual file system that is designed and implemented to provide high I/O performance and high reliability. A global distributed storage system for wide-area network storage is discussed in detail in the paper, where a Storage Service Provider is added to provide storage service and plays the role of user agent for the storage system. Object based Storage Systems not only store data but also adopt the attributes and methods of objects that encapsulate the data. The adaptive policy triggering mechanism (APTM), which borrows proven machine learning techniques to improve the scalability of object storage systems, is the embodiment of the idea about smart storage device and facilitates the self-management of massive storage systems. A typical offline massive storage system is used to backup data or store documents, for which the tape virtualization technology is discussed. Finally, a domain-based storage management framework for different types of storage systems is presented in the paper.     

Global behavior of dynamical agents in directed network

This paper investigates the global behavior of controlled dynamical agents in directed networks. The agents are Lyapunov stable, are distributed in a line, and communicate through a directed network. The communication topology of the network is characterized by a directed graph and the control protocol is designed in simple linear decentralized feedback law. We study the different conditions under which agents will achieve aggregation, and critical and divergent trajectories, respectively. Our investigation on the dynamical agent system under network is extended to the time-delay network case. Furthermore, we study the case with two pre-specified virtual leaders in the system. Numerical simulations are given and demonstrate that our theoretical results are effective.     

MADIDS：基于移动代理的分布式入侵检测

传统的IDS在WAN上配置时，通常会出现计算瓶颈和维护更新不易等问题。本文提出了一种基于移动代理的新型分布式入侵检测系统（Mobile Agent Distributed IDS）。MADIDS是针对WAN环境专门设计的，数据的处理通过各节点所设置的代理来进行分布式计算，不仅能实现全网络范围内的入侵检测功能，具有良好的可移植性；而且对网络系统和主机的资源占用较低，减少出现网络瓶颈的可能。文中建立了MADIDS的体系结构和理论分析模型，并讨论了MADIDS的维护更新机制。     

基于移动agent的分布式入侵检测系统研究*

为了提高现有分布式入侵检测系统的效率和性能,提出了一种基于移动agent的分布式入侵检测系统模型。将移动agent技术应用于入侵检测中,并给出了其移动agent间的可靠通信方法,实现了agent的协同检测。实验结果表明,由于移动agent的应用,入侵检测系统的节点成为了可移动的部件,从而使该模型具有了更强的抗攻击性和入侵检测能力。     

高速网络环境下的网络入侵检测系统的研究

高速网络环境下的入侵检测是一个新的研究方向。基于负载均衡技术和协议分析技术，提出了一个能够应用在高速环境下的网络入侵检测系统。负载均衡技术把在前端捕获的高速数据流进行分化，以利于后端处理；协议分析技术利用网络协议的层次性和相关协议的知识快速地判断攻击特征是否存在。基于代理的分布式体系结构，增强了系统的可扩展性，提高了系统的检测效率。     

一种基于MA的分布式入侵检测系统研究

分布式入侵检测系统有许多优点,如可测量性和抗破坏性。然而,在具体实施过程中存在着许多障碍。移动代理(MA)技术有着适合分布式入侵检测系统具体实施的许多特性。基于移动代理的分布式入侵检测系统利用移动代理技术同等地处理来自每台被监视主机的信息,然后完成对入侵行为的全局信息提取。本文深入分析了一种基于移动代理的分布式入侵检测系统。     

一种基于智能主体的分布式入侵检测系统设计与实现

针对分布式入侵检测系统存在的单点失效和处理能力瓶颈问题,设计并实现了一种基于智能主体的分布式入侵检测系统。该系统基于多种智能主体的分布式结构,在进行入侵检测时,采用按需装配的方式,通过对入侵攻击特征信息中的关联信息进行处理,降低了入侵检测算法的复杂度,提高了系统的入侵检测能力。通过对该系统的仿真,入侵攻击检测准确率达到96%,结果表明其性能要好于其他的入侵检测系统。     

利用分割机制实现高速网下入侵检测的研究

目前基干网络的入侵检测系统已经无法适应高速增长的网络速度。文章提出了一种基于某种分割机制的分布式方案，它能够在高速链路上对网络进行实时的入侵检测，并给出了一个实验模型与相关的性能测试。     

Snort入侵检测系统中数据包捕获模块的分析与设计

随着网络的高速发展,网络带宽得到了极大的提升。高速网络环境下对入侵检测系统提出了更高的要求,其中入侵检测系统的数据包捕获能力成为其发展的瓶颈。目前大多数系统使用传统的Libpcap库来实现数据包捕获功能,文章对一个基于Snort入侵检测系统中数据包捕获模块进行了分析设计,给出了设计架构,详细说明了工作流程,并对系统的性能进行了对比分析。     

5G/B5G毫米波网络TCP传输性能分析

5G / B5G移动通信系统的高带宽、高可靠性和低延迟的通信需求需要更多新技术的支持. 毫米波由于其丰富的频谱资源和极高的带宽容量而成为5G/B5G移动通信系统的研究热点之一. 不同于以往由有线网络主导的互联网架构, 如今的移动互联网已经成为无线接入网和高速核心网的融合. 但是目前对毫米波端到端通信传输性能的研究工作还相对较少, 而且多采用仿真实验. 本文利用真实网络设备, 通过开展真实网络环境下的实验, 对毫米波链路基本传输性能和5G/B5G毫米波网络端到端通信系统中TCP传输性能进行测量分析, 研究5G/B5G毫米波网络传输过程中的链路瓶颈, 为设计毫米波端到端网络传输协议, 提高网络传输吞吐率奠定基础.     

基于移动代理、关键主机隐藏技术的IDS体系结构

本文介绍了一种安全灵活的入侵检测系统体系结构，通过运用关键主机隐藏技术，使关键主机对于主动探测，被动监听均不可见，提高了系统自身的安全性，同时，通过引入移动代理，限制入侵检测系统各部分之间的通信等机制，增强本体系结构对于拒绝服务攻击的抵抗力，系统通过使用智能移动代理在网络节点上收集处理信息，提高了入侵检检测系统的灵活性，减少了网络负载。     

一种基于移动代理的分布式IDS模型研究

传统的分布式层次型入侵检测系统也有难以克服的缺陷，在层出不穷的攻击方式面前容易崩溃。本文提出了一种基于移动代理的IDS模型，它综合了两个领域的研究成果：分布式IDS和移动代理(MA)。通过安全分析表明，该模型提供了较好的安全构架。