Application server

Such systems can reside on the organization s intranet or over the Internet. Various types of hardware and software are needed to host a website. The hardware includes switches, gateways, and routers. Software includes, among others, application servers, database servers, web servers, authentication servers, and firewalls. On the other hand, the only hardware and software... 

In web-based application models that use web browsers to display information sent by the application server, the largest part of the data management applications reside on the server. This model has many advantages over the distributed model, but it has important limitations (1) All participating sites must have an Internet connection (2) it requires the ability to constantly be... 

In our view, architecture is not only about Gothic-scale structures but is also about all structures and relationships used down to the level of code.1 The decision to use a four-tier structure, with a thin client, a Web server, a business application server, and a database, is architectural. But, in the extreme, we consider a consistent use of getXQ and setX(x) methods also to be part of the (detailed) architecture. This view leads to a somewhat less formal definition of architecture. 

Use a three-tier client-server architecture. All business logic must be in the middle tier, presentation and dialog on the client, and data services on the server. In this way you can scale the application server processing independently of persistent storage. 

MDL embeds Oracle9i Application Server technology in MDL Discovery Framework more >>... 

These abstraction layers offer tremendous benefits to the software development process with reduced development complexity and costs and increased productivity. Application server platforms and blueprints also provide software development frameworks to help the software fit into specific architecture patterns. One of the most commonly adopted software architecture patterns for enterprise systems is the layered architecture (Buschmann et al., 1996 Fowler, 2003a). It is also the heart of the J2EE blueprint (Alur et al., 2003). 

Web-based systems offer several advantages over rich client easy to deploy and access, easy to scale (by adding more hardware resources to the application server), and shared computing resources (CPUs, memory, database connections). However, most of the information this book presents is not limited to Web-based applications. It promotes the loosely coupled Presentation Layer and Domain Layer so that business logic can be reused no matter what GUI technology is being used. 

Installation of the presentation application is considered an installation of the application server. It installs and configures an apache web server and creates an administrative database. The administrative database holds the configuration of the web site (users, roles, graphics, languages, events databases) and the configuration of the enrichment and correlation processes with respect to each event database known to the web site. An event database does not need to reside on the presentation server, but is specified using a connection string. An event database can be accessed from multiple presentation sites. 

The resulting experimental designs are saved to the Renaissance Application Server (RAS), where they provide a record of the compositional makeup of each sample in the design. The designs also provide the process conditions under which the sample was created for assessing composition/property relationships. 

Many infrastructure components will be subject to standard build specifications, e.g.. Print Servers, Application Servers, Domain Servers, etc. As such, it may be possible to develop standard, reusable Qualification protocols that can be reexecuted each time a new server is built and installed. 

This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Sports, and Culture. The calculations were partly carried out by the application server Silicon Graphics Inc. POWER CHALLENGE... 

Communication with a Web Service (using the XML-based Simple Object Access Protocol, SOAP [974]) is normally comprised of uncompressed text messages. The invocation of a Web Service is performed by a specially formed request to a web server or an application server. No absolute guarantees can be made either regarding the reachability of a particular Web Service or its temporal characteristics. 

Correct installation and conhguration of all systems of the supporting software environment — that is, the operating system, servers (e.g., application server, database server), and other components of a multitier system. 

Client-to-server for communication of clients to their application servers that are hosting the business logic. 

Server-to-server for data transfer between different application servers or between database server and application server. 

Agents provide an interface to plug in different types of converters. File converters translate data from instrument vendor-specific or indnstry-standard formats into native or human-readable formats. Common indnstry standardized formats are, for instance, JCAMP (e.g., DX, JDX, CS), ANDI, AIA, NetCDF, MDL Molflle and related formats (e.g., SD, SDF), ASCII formats (ASC, TXT, CSV), and XML-based formats. Most of the commercially available instrument software can import or export one of these formats. Conversion can either be done using an implemented converter in the application server of the target software or by specifying an executable for streaming conversion. 

Agents report data to the target application server only when new or changed data exists. 

Agents can handle data overflow and can send data to the application server in a timely, correct, and traceable manner. 

Agents support data buffering and hold data communication with the target application server in case of system failure and restore it as soon the system is operational again. 

Agents are able to establish and maintain data communication between software and a device or instrument and to communicate to the target software application server asynchronously. They are installed either on the computer that runs the source application or on a separate server if multiple regular transfer tasks are expected. 

If an agent transferred data to an application server, the client software requires some functionality to view and use these data. One solution is the concept of a generic inbox. Similar to an e-mail inbox, this feature allows receiving converted files sent from a software agent in the client application. 

Application Server An OS/2-based computer that manages the software that is distributed to all application workstations. It takes care of communication between workstations and database server. 

It is clear that one of the reasons ERP tools became so successful was that they were able to take advantage of improvements in the client/server architecture and in middleware. The general movement to the client/server platform in the late 1980s meant that firms could reduce the cost of a highly centralized configuration in favor of a more flexible client/server setup. The C/S configuration preferred by most ERP vendors is that of the standard three-tier C/S platform, which consists of a presentation server, connected to the application server, which is in turn connected to the database... 

In a three-tier architecture, the second tier plays the most important role. Many functions such as data access and connection with other systems are located in the second tier and can be used by any client. That is, the second tier becomes the gateway to other systems. The second tier is often called the application server. 

The advantages of three-tier architecture derived from the application server are ... 

Reduction of network traffic Concentrating the function of accessing database and other systems on the application server makes it possible to reduce network traffic between the client and the server. That is, instead of interacting with the database directly, the client calls the business logic on the application server, and then the business logic accesses the database on the database server on behalf of the client. Therefore, only service requests and responses are sent between the client and the server. From the viewpoint of network traffic, comparisons of two-tier architecture and three-tier architecture are shown in Figure 7. 

Scalability Adding or removing application servers or database servers allows the system to be scaled incrementally according to the number of clients and volume of requests. 

Performance Because workloads can be distributed across application servers and database servers, this architecture can prevent an application server from becoming a bottleneck and can keep the performance of the system in a permissible range. 

---