Seleclting Middleware for N-tier applications

This paper describes middleware for n-tier architecture, describes how this middleware is meeting the unique demands of Internet applications and e-commerce, and suggests selection guidelines to assist business managers in choosing appropriate types of middleware for n-tier systems that will meet their internet needs. Different types of middleware provide the functionality for addressing many distinct and disparate problems arising from the distributed processing associated with n-tier systems. This paper associates the type of middleware with the nature of the system being developed

Building a Robust Web Application

Change is inevitable. Software applications must be prepared for that inevitable moment by following structured robust software design and architecture. Utilizing popular n-tier architectures and robust philosophies in web applications enables developers to implement robust systems that are prepared for the unknown future. This project highlights and demonstrates robust software development techniques in a prototype web application using an n-tier architecture. The examples are designed to provide a robust philosophy that can be applied to similar robust solutions for other development efforts

A few elements in software development engineering education

International audienceBrest University offers the software engineering by immersion paradigm as an alternative to other education systems. The idea is that students follow through a project from A to Z, relying on an ISO9001 quality management system alongside methods and tools associated with present n-tier architecture - but under apprenticeship conditions. Software engineering activities are structured around three main processes: Development Engineering, Project Management, and Development Support. Focussing on Development Engineering, we report on certain challenges and difficulties, illustrated on a real-scale project

Multi Site Coordination using a Multi-Agent System

A new approach of coordination of decisions in a multi site system is proposed. It is based this approach on a multi-agent concept and on the principle of distributed network of enterprises. For this purpose, each enterprise is defined as autonomous and performs simultaneously at the local and global levels. The basic component of our approach is a so-called Virtual Enterprise Node (VEN), where the enterprise network is represented as a set of tiers (like in a product breakdown structure). Within the network, each partner constitutes a VEN, which is in contact with several customers and suppliers. Exchanges between the VENs ensure the autonomy of decision, and guarantiee the consistency of information and material flows. Only two complementary VEN agents are necessary: one for external interactions, the Negotiator Agent (NA) and one for the planning of internal decisions, the Planner Agent (PA). If supply problems occur in the network, two other agents are defined: the Tier Negotiator Agent (TNA) working at the tier level only and the Supply Chain Mediator Agent (SCMA) working at the level of the enterprise network. These two agents are only active when the perturbation occurs. Otherwise, the VENs process the flow of information alone. With this new approach, managing enterprise network becomes much more transparent and looks like managing a simple enterprise in the network. The use of a Multi-Agent System (MAS) allows physical distribution of the decisional system, and procures a heterarchical organization structure with a decentralized control that guaranties the autonomy of each entity and the flexibility of the network

A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing

This article proposes a design and implementation of a low cost two-tier architecture model for high availability cluster combined with load-balancing and shared storage technology to achieve desired scale of three-tier architecture for application load balancing e.g. web servers. The research work proposes a design that physically omits Network File System (NFS) server nodes and implements NFS server functionalities within the cluster nodes, through Red Hat Cluster Suite (RHCS) with High Availability (HA) proxy load balancing technologies. In order to achieve a low-cost implementation in terms of investment in hardware and computing solutions, the proposed architecture will be beneficial. This system intends to provide steady service despite any system components fails due to uncertainly such as network system, storage and applications.Comment: Load balancing, high availability cluster, web server cluster