Large-scale Network Environment Research Articles

Distributed application configuration, management, and visualization with plush

Support for distributed application management in large-scale networked environments remains in its early stages. Although a number of solutions exist for subtasks of application deployment, monitoring, and maintenance in distributed environments, few tools provide a unified framework for application management. Many of the existing tools address the management needs of a single type of application or service that runs in a specific environment, and these tools are not adaptable enough to be used for other applications or platforms. To this end, we present the design and implementation of Plush, a fully configurable application management infrastructure designed to meet the general requirements of several different classes of distributed applications. Plush allows developers to specifically define the flow of control needed by their computations using application building blocks. Through an extensible resource management interface, Plush supports execution in a variety of environments, including both live deployment platforms and emulated clusters. Plush also uses relaxed synchronization primitives for improving fault tolerance and liveness in failure-prone environments. To gain an understanding of how Plush manages different classes of distributed applications, we take a closer look at specific applications and evaluate how Plush provides support for each.

Architectural Pattern of Health Care System Using GSM Networks

Large-scale networked environments, such as the Internet, possess the characteristics of centralised data, centralised access and centralised control; this gives the user a powerful mechanism for building and integrating large repositories of centralised information from diverse resources set. However, a centralised network system with GSM Networks development for a hospital information systems or a health care information portal is still in its infancy. The shortcomings of the currently available tools have made the use of mobile devices more appealing. In mobile computing, the issues such as low bandwidth, high latency wireless Networks, loss or degradation of wireless connections, and network errors or failures need to be dealt with. Other issues to be addressed include system adaptability, reliability, robustness, extensibility, flexibility, and maintainability. GSM approach has emerged as the most viable approach for development of intelligent software applications for wireless mobile devices in a centralized environment, which gives higher band width of 900 MHz for transmission. The e-healthcare system that we have developed provides support for physicians, nurses, pharmacists and other healthcare professionals, as well as for patients and medical devices used to monitor patients. In this paper, we present the architecture and the demonstration prototype.

Random walk with jumps in large-scale random geometric graphs

The information dissemination problem in large-scale networking environments like wireless sensor networks and ad hoc networks is studied here considering random geometric graphs and random walk based approaches. A new type of random walk based agent is proposed in this paper and an analytical expression with respect to coverage (i.e., the proportion of the network nodes visited by the random walk agent) as a function of the number of the agent movements is derived. It is observed that the cover time of many of already existing random walk based variants is large in random geometric graphs of low degree (as it is commonly the case is wireless environments). As this inefficiency is attributed (as discussed in the paper) to the inability of existing random walk based solutions to move away from already likely covered areas, a mechanism for directional movement (i.e., jumping) of the random walk based agent is proposed and studied, that allows the agent to jump to different network areas, most likely not covered yet. The proposed mechanism (Jumping Random Walk) is studied analytically and via simulations and the parameters (of the network topology and the mechanism) under which the proposed scheme outperforms existing random walk based variations are determined.

Scalable service migration in autonomic network environments

Service placement is a key problem in communication networks as it determines how efficiently the user service demands are supported. This problem has been traditionally approached through the formulation and resolution of large optimization problems requiring global knowledge and a continuous recalculation of the solution in case of network changes. Such approaches are not suitable for large-scale and dynamic network environments. In this paper, the problem of determining the optimal location of a service facility is revisited and addressed in a way that is both scalable and deals inherently with network dynamicity. In particular, service migration which enables service facilities to move between neighbor nodes towards more communication cost-effective positions, is based on local information. The migration policies proposed in this work are analytically shown to be capable of moving a service facility between neighbor nodes in a way that the cost of service provision is reduced and - under certain conditions - the service facility reaches the optimal (cost minimizing) location, and locks in there as long as the environment does not change; as network conditions change, the migration process is automatically resumed, thus, naturally responding to network dynamicity under certain conditions. The analytical findings of this work are also supported by simulation results that shed some additional light on the behavior and effectiveness of the proposed policies.

Design of service-oriented asynchronous messaging middleware

Service-Oriented Architecture (SOA) can offer open standards to integrate inter-enterprise applications, but it cannot fully support complex Internet applications characterized by asynchronous transfer and high reliability. Traditional Message-Oriented Middleware (MOM), being loosely coupled and asynchronously reliable, is suitable for enterprise integration. But it is too unscalable and inflexible to expand into large-scale network environment. This paper designed a structure of service-oriented Asynchronous Messaging Middleware (called s-AMM), which fully adopted the advantages of SOA and MOM, and analyzed some key technologies such as message transfer, service re-composition and security service. Furthermore, s-AMM is proved to be feasible and effective by mobile E-commence case.

VON: a scalable peer-to-peer network for virtual environments

The scalability of large-scale networked virtual environments (NVEs) such as today's massively multiplayer online games (MMOGs) faces inherent limits imposed by client-server architectures. We identify an emerging research direction that applies peer-to-peer (P2P) networks in order to realize more scalable and affordable NVEs. The central issue for P2P-based NVE (P2P-NVE) systems is to correctly and efficiently maintain the topology of all participating peers by solving the neighbor discovery problem. We also propose the Voronoi-based overlay network (VON), a simple and efficient design that maintains the P2P topology in a fully-distributed, low-latency, and message-efficient manner. Simulation results show that by bounding the per-node resource consumption, VON can be fundamentally more scalable than existing methods while achieving high topology consistency and reliability.

Evaluating IPv6 on a large-scale network

We evaluate an ideal model and a real large-scale network environment using available end-to-end measurement techniques that focuses on a large-scale IPv6 backbone and made performance comparisons between the current Internet (IPv4) and next generation Internet (IPv6). In this paper, we compiled the performance statistics of each network in terms of TCP and UDP throughput, delay jitters, packet loss rate, and round trip time. Our conclusions show that, in a real large-scale network environment, a minor degradation in the throughput of the TCP, a slightly higher throughput of the UDP, a somewhat emerging frequency of the delay jitter, a lower packet loss rate, and a slightly longer round trip time happens when we compare the IPv6 network to the IPv4 network.

A scalable P2P platform for the knowledge grid

The knowledge grid needs to operate with a scalable platform to provide large-scale intelligent services. A key function of such a platform is to efficiently support various complex queries in a dynamic large-scale network environment. This paper proposes a platform to support index-based path queries by incorporating a semantic overlay with an underlying structured P2P network that provides object location and management services. Various distributed indexing structures can be dynamically formed by publishing, semantic objects as indexing nodes. Queries are forwarded along the chains of semantic object pointers to search for objects. We investigate the deployment of a scalable distributed trie index for broadcast queries on key strings, propose a decentralized load balancing method for solving the problem of uneven load distribution incurred by heterogeneity of loads and node capacities and by the distributed trie index, and give an approach for improving the availability of the semantic overlay and its trie index. Experiments demonstrate the scalability of the proposed platform.

A Peer-to-Peer Message Exchange Scheme for Large-Scale Networked Virtual Environments

Massively multiplayer online games and other multi-user based networked applications are becoming a big business today. Such technology has long been researched in the area called networked virtual environments (Net-VE). With the recent deployment of broadband access technologies, the increase of the number of participants is putting pressure on the Net-VE systems. The conventional systems coped with the scalability problem by segmenting players onto multiple servers or multicast groups. limiting the number of users that could interact with each other. These schemes. however, force developers to invest enormous money on hardware and spend much time on building complex software systems. In this paper, we present a fully distributed communication protocol for large-scale networked virtual environments. As the entities in this scheme are directly connected to each other by unicast no special infrastructure such as multicast or costly central servers is needed. Simulation results show that this architecture is scalable to the increase of the number of participants in the Net-VE system.