Performance comparison of remote procedure calling and mobile agent approach to control and data transfer in distributed computing environment

The paper presents a prototype implementation of a Java-based mobile agent architecture. The main focus lies on service trading and easy access to various services for mobile agents. The mediator for both mobile and service agents is called Service Center which is a crucial constituent of each agent platform within the mobile agent infrastructure. It allows to independently program services and mobile agents based on the generic agent concept. Another advantage of the Service Center architecture is the exploitation of an already existing LDAP server that is used as the distributed service directory for mobile agents.

Random number generators are integral components to Monte Carlo codes. They provide the pseudorandom number sequence used to actually sample the distributions of interest. As a result, they are one of the most important components to the software. The current recommended MCNP random number generator is a 63-bit linear congruential generator (LCG). This generator is quite fast, but it has some drawbacks. First, it only has a period of 2⁶³. Due to the necessarily non-optimal usage of random numbers to ensure parallel reproducibility, this amount is too few to guarantee random number sequences are not reused in all configurations the code runs under. As simulation size increases, users will need to be aware of the limitations of the generator and tune configuration variables to best suit their simulations, or they will need to assume that reuse is not negatively affecting their answers. Neither of these are optimal. Second, small LCGs are fairly weak in bit generation quality, and this can have an unknown impact on the quality of the simulation. This paper is an investigation into whether or not more modern random number generators can supersede the current ones. The goal is to find a generator that is similar or superior in speed to the LCGs, has a state space large enough to make strong guarantees about random number reuse, and passes all modern random number test suites. If such a generator is found, it would eliminate the need for the user to even be aware of the limitations of the random number generator and would simplify the use of the code. This paper will be broken into several parts. Sec. 2 will discuss the evolution of the random number generator within the MCNP code. Sec. 3 will go over what a Monte Carlo code needs from a generator to be reproducible and portable and how the current generator behaves in that light. Sec. 4 goes through how each generator was tested. Finally, Sec. 5 will discuss improvements that could be made to the code.

Linear congruential random number generators are widely used in simulation and Monte Carlo calculations. Because they are very fast, and because they have minimal state space, they remain attractive for use in parallel computing environments. We discuss their use as a source for many streams of pseudo-random numbers. Many authors have discussed splitting the stream of a single CRNG into many substreams; we show spectral calculations for this scheme and compare randomly and regularly spaced selection of starting points. Several authors have suggested using a common multiplier for all streams and a unique additive constant for each. The discrepancies of such schemes are no better than for splitting schemes; we show how they are in a sense equivalent. We also consider the use of distinct multipliers for each stream. Good multipliers are abundant for large enough moduli, but little is known about the multidimensional behavior of such generators. We discuss the use of improvement techniques and larger moduli to overcome the limitations of linear congruential generators.

This paper presents a mailbox-based scheme for designing flexible and adaptive message delivery protocols in mobile agent (MA) systems. The scheme associates each mobile agent with a mailbox while allowing the decoupling between them, i.e., a mobile agent can migrate to a new site without bringing its mailbox. By separating the concerns of locating the mailbox of a mobile agent and delivering a message to the agent, we obtain a large space of protocol design with flexibility. Using a three-dimensional model based on the scheme, we have developed a taxonomy of MA communication protocols, which not only covers, as special cases, several known MA message delivery protocols, but also allows for the design of new ones well suited for various application requirements. We describe such an efficient and adaptive protocol derived front the model. The protocol guarantees reliable delivery of messages to mobile agents. We analyze the design trade-offs and performance of the protocol, using an analytic model as well as extensive simulation experiments.

Mobile Agent paradigm is said to give better performance advantages over other paradigms due to its features especially in the network and the internet applications. To integrate mobile agents into such applications, fault tolerant ability of an agent is one of the most important issues. The paper analyzes the Fault Tolerant Mobile Agent execution System "FTMAS" model proposed in [1] and studies the performance mathematically. The paper defines and analyzes the migration time MT, the Round trip time RTT, the transfer time TrT and the system throughput Thr. They are tested against 3 performance metrics: the average connectivity of the network, the agent size and the probability of failure. The performance analysis proves that our proposed FTMAS is a promising model in the fault tolerant field of the mobile agent MA execution.

The problem of managing large computer networks in enterprises is very complex. This requires an integrated network management system that aids the work of the network manager. A distributed network management system is necessary when the network grows to a large size. A distributed network management system using mobile agents can provide greater flexibility, less data transfer and dynamic load distribution. Much of the research in this area is in its infancy, so the available resources are scarce, and mobile agent based network management systems are not readily available. This paper presents a design of IITB_View, a distributed network management system based on SNMP technology and on the concept of mobile agents under a framework of the management-by-delegation model. In order to illustrate the concepts involved, the system has been implemented over a small portion of the IIT Bombay campus network. The implementation uses the publicly available IBM Aglets workbench. Some initial experiments conducted with the implementation indicate that mobile distributed processing of management data does perform better compared to its centralized counterpart. Also, IITB_View adapts quickly through on-line learning using neural network techniques. This experience of ours and results of the research conducted by others lend support to the claim that mobile agents present a technology that will become very useful, and perhaps even critical in many areas of system and network management.

So far, agent research can be broadly categorized into two areas: intelligent agents and mobile agents. Intelligent agent research has grown from a background of AI, humancomputer interaction, and autonomous systems, while mobile agents research stems from the areas of distributed computing and networked systems. Intelligent agents research addresses intelligent control, planning, domain modeling, user modeling, perception, interagent cooperation, and adaptivity. Intelligent agents can take on many different roles, ranging from representing a human user’s interests to actively collaborating with users and each other. Intelligent agents are being designed to tackle nearly every tedious, non-creative activity that people perform (e.g., Web searches), as well as many more abstract functions (e.g., entertainment). Major issues in intelligent agents research include knowledge representation and communication, architectures for intelligent autonomy, mixed-initiative behavior, collaboration techniques, and learning. Mobile agents address physical communication, agent mobility, tracking and locating mobile agents, security and reliability of agents, etc. Mobile agents are suited for optimizing communication ‐ moving the action towards the source of data ‐ and thereby avoiding the need for huge data transfers. This is beneficial in data-intensive applications such as data mining. Mobility can also improve reliability in certain cases. In the field of electronic commerce, mobile agents naturally reflect the characteristics of buyer and the seller, effectively playing the roles of traveling salesman or broker. They can also be applied for easier software customization, software distribution, and to represent disconnected users. The main issues are in security, providing the infrastructure on the Web (naming, locating, controlling, and messaging) and improving survivability. The biggest challenge for all new agent technology is developing successful applications. For this minitrack, we selected two characteristics of agents that can span the diverging areas of intelligent and mobile agents: mobility and communication. The accepted papers reflect the research issues described in this summary. The minitrack is organized in three sessions. The first session explores the coordination of multiple intelligent agents using dramatically different communication schemes. Andersson and Ygge present an efficient market-based approach to managing very large scale groups of agents engaged in coordination via producer/ consumer transactions. Their CoTree algorithm allows largescale markets to operate efficiently with sparse communication, rapid updates as agent preferences change, and minimal data caching requirements on massively distributed systems. In contrast, Nelson, Penner, and Soken discuss the Interaction Society model of coordination, in which relatively small-scale groups of knowledge-intensive agents collaborate using complex communication about discrete tasking and information requirements. Their model for inter-agent communication and interactions with human users is being applied to build a multi-agent advising system for coordinating military Search and Rescue operations. Finally, Barbuceanu discusses the role of obligations and interdictions in the context of coarse-grain agent interactions. By explicitly capturing social obligations and the costs associated with violating those constraints, he shows how rational agents can achieve coordinated behavior without necessarily sharing goals. The second session addresses Java-based mobile agent systems. The paper by Covaci, Busse and Zhang, describes how a mobile agent system can be used for network management. Their framework is based on existing solutions such as TMN, and can be extended to SNMP.

Mobility management is a necessity in highly dynamic and large-scale Mobile Agent (MA) networks, especially in a multi-region environment, in order to control and communicate with agents after launching. In this paper, we have proposed a hierarchical mobile agent monitoring mechanism using Mobile Monitor Agents (MMA’s). The mobile agent system is implemented in XML. This XML based system provides a system independent, standardized, effective and customized solution for application development. Distributing MMA dynamically solves the scalability issue of Centralized monitoring mechanism, and still has the advantages of Hierarchical monitoring mechanism to decrease the information processing bottleneck issue at centralized server. The MMA takes care of a certain number of agent servers and it reduces the traffic in the centralized server by bypassing queries from the agent servers under its control. XML helps to decrease the amount of data transferred and the processing part with the Java parsers is not transferred in network. There is less transfer of data because only data representation is migrated.KeywordsAgent ServerMobile AgentsMobile Monitor Agent

This paper covers the design and implementation of a generic model, based upon Mobile Agents, to perform PVC configuration management functions in multi-vendor ATM networks. The paper introduces an alternative or complement to existing ATM configuration management solutions. In it, an autonomous mobile agent travels from switch to switch to perform its configuration duties. A prototype implementation written in the Java programming language was developed for the validation of the proposed solution and was tested using a simulation testbed also written in Java.KeywordsMobile AgentNetwork ManagementAsynchronous Transfer ModeObject Management GroupJava Virtual MachineThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The original Web did not support multiuser, interactive applications. This shortcoming is being studied, and several approaches have been proposed to use the Web as a platform for programming Internet applications. However, most existing approaches are oriented to centralized applications at servers, or local programs within clients. To overcome this deficit, we introduce PageSpace, that is a reference architecture for designing interactive multiagent applications. We describe how we control agents in PageSpace, using variants of the coordination language Linda to guide their interactions. Coordination technology is integrated with the standard Web technology and the programming language Java. Several kinds of agents live in the PageSpace: user interface agents, personal homeagents, agents that implement applications, and agents which interoperate with legacy systems. Within our architecture, it is possible to support fault-tolerance and mobile agents as well.

In wireless sensor networks, the mobile agent technology is used in data transmission from one cluster to another cluster. The Optimization of mobile agent in the routing within the clustering algorithm for wireless sensor networks to further reduce the amount of data transfer. the main objectives of wireless sensor network design is to improve the energy efficiency & effective utilization of sensor nodes to prolong the lifespan of a wireless network .This paper presents an effective clustering algorithm, which is an extension to the LEACH routing algorithm., this algorithm fully utilizes the location information of network nodes in routing to reduce the routing cost. Through a clustering approach of intelligent mobile agents, it is possible to reduce the cost of time for each individual agent, here the problem of Multiple Clustering of Mobile Agents (MCCMA) where the decision is to cluster mobile agents such that a group of similar intelligent mobile agents will visit a group of similar sensor nodes are compare with location based clustering algorithm of wsn. both of Simulation results indicate that these algorithm & approach of mobile agent & wireless sensor network Nodes can have balance nodes' energy consumption and prolong the network's life span. It also has good extensibility & stability

With the increase in the number of mobile users, the need for new type of services and applications is also on the rise. Particularly, a growing area of interest is to provide location dependent services to the mobile users. In this paper, we present a system that supports distributed processing of location-dependent continuous queries on distributed mobile data in a mobile environment using mobile agents. We investigate a scenario in which both the querying unit and the object being queried (target object) are capable of movement and the mobile unit is equipped with more powerful capabilities, including the storage of a small database and the capacity of data processing. Since our system deals with continuous queries, we propose a shared incremental update mechanism, which caches the results of the previously evaluated queries and avoids redundant results thereby minimizing the data traffic in wireless environment. To further reduce the data transfer we share the cached data among different queries. Our system uses mobile agents for evaluating queries, which involves data from both the server and mobile unit, and it helps in parallel processing of data and it, can efficiently track the mobile units involved in the system. The conventional query processing method like join processing of data from mobile units and server is directly applied in the mobile environment.

Summary form only given. We have discussed a mobile multi-agent based framework to address the aspect of topology discovery in ad hoc wireless network environment. In other words, we have designed a multi-agent based protocol to make the nodes in the network topology aware. Our primary aim is to collect all topology-related information from each node in the network and distribute them periodically (as updates) to other nodes through mobile agents. The notion of stigmergic communication has been used through the implementation of a shared information cache in each node. Moreover, we have used a concept of link stability and information aging based on which a predictive algorithm running on each node can predict the current network topology based on the current network information stored at that node. We have demonstrated through performance evaluation of a simulated system that the use of mobile multi-agent framework would be able to make each node in the network topology aware without consuming large portion of network capacity. This would eventually help us to implement a proactive routing protocol without much overhead. Moreover, as a direct outcome of infiltrating topology information into the nodes, the foundations for designing distributed network management and implementing communication awareness get automatically laid.

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. This paper was prepared for the 43rd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Tex., Sept. 29-Oct. 2, 1968. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract Drilling exploratory wells in the petroleum industry is an economic undertaking petroleum industry is an economic undertaking in which the probability of success of the individual venture is low, but the payoffs from successful wells compensate for the costs of the failures. There is a recent trend toward expressing the possible payoffs in terms of a probability distribution. probability distribution. Appraisal methods were developed that were predicated toward the use of a predetermined predicated toward the use of a predetermined risk factor, as is generally used in statistical decision methods. Cumulative values of groups of exploratory ventures were shown by computer simulation to approximate closely the normal distribution. Solutions developed include determination of the maximum fractional participation in a relatively large venture, participation in a relatively large venture, determination of the maximum appraisal price consistent with financial resources of the economic unit, and determination of the value of information that increases the chance of success. A maximum appraisal price is limited by required expected rate of return when capital resources are very large. However, the appraisal price is dominated by risk where capital resources are not relatively large. Introduction The evaluation of petroleum exploratory ventures is concerned with the appraisal of economic undertakings wherein the probability of complete failure of the individual venture is high and the probability of success is low and the magnitude of the occasional success itself is variable. For an individual well, even when it is located with geologic guidance, there is quite a low probability of discovering sufficient quantities of oil to repay the drilling and completion costs. However, where a drilling program consists of a score of such wells, there is often a high probability that the better discoveries will repay the costs of the entire program as well as pay the necessary profits. profits. Several of the methods that have been proposed for evaluate exploratory ventures have proposed for evaluate exploratory ventures have used an expected value, if successful, in combination with some method for handling the relative success ratio. The binomial distribution has been used for describing the distribution of occurrences of successful and unsuccessful trials, and the lognormal distribution has been recognized as adequate for describing the distribution of sizes of resource deposits.

Packet buffering-and-forwarding is a simple but essential mechanism and has been widely used with other mechanisms to provide seamless handoffs in many wireless/mobile networks. However, some undesirable side effects of this mechanism, if not managed appropriately, can easily diminish its effectiveness in providing seamless inter-cell transitions during a handoff. We first examine these side effects and show how inappropriate buffer management by a mobility agent could affect the TCP performance. The throughput of TCP is then studied with special emphasis on the effects of a handoff. We enhance the conventional buffering-and-forwarding by proposing the last-come-first-drop (LCFD) buffer management policy (to be employed by mobility agents) and post-handoff acknowledgement suppression (to be used by mobile nodes). Our enhancements are backward compatible and suitable for the gradual/incremental deployment. By deriving an analytical model and conducting numerical analysis, we show that our scheme can improve the TCP throughput up to 30%. Finally, we conduct the ns-2 based simulation to confirm these numerical results, and demonstrate the applicability of the analytic model for predicting TCP throughput in other handoff schemes