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Introduction

1.1 The Internet Has Changed Everything

The Internet has introduced enormous opportunities for companies to customize and streamline their internal business processes. But these opportunities bring new challenges: Applications must be made available on the Internet in rapid time and must scale to serve very high numbers of users.

The use of middle tier application servers promises to shrink development time and expense by providing scalable infrastructure, transactional management, portal services, business intelligence functionality, and integration.

Unfortunately, most vendors' application server products target only a subset of these services, leading customers into the dark, tangled forest of integrating products from multiple vendors.

1.2 The Oracle Internet Platform

Oracle helps its customers find a clear path through this heavy growth by offering a simple, complete, and integrated Internet platform composed of three core products:

• The Oracle8i database

• Oracle9i Application Server

• Oracle9i Developer Suite

One way Oracle's Internet Platform reduces the total cost of ownership of a corporate IT infrastructure is by eliminating the expense of integrating multiple products from various vendors. With the Oracle Internet Platform, customers can refocus their IT resources on creating true, value-added services to differentiate themselves from their competitors.

Oracle9i Application Server combines with Oracle8i and the Oracle9i Developer Suite to provide everything necessary to build, deploy, and manage Internet applications. Together, they constitute an Internet platform that is simple, complete, and integrated.

1.2.1 Simple

Oracle9i Application Server, Oracle8i, and Oracle9i Developer Suite are simple to buy, simple to install, and simple to manage. All of Oracle's core middle-tier services and core development tools, including Oracle9i Application Server Form Services and Oracle Forms Developer, have been integrated. Application services have been integrated into Oracle9i Application Server. Development tools have been integrated into Oracle9i Developer Suite. These integrations enable customers to build and deploy portals, transactional applications, and business intelligence facilities with just three products.

1.2.2 Complete

With Oracle8i to manage data, Oracle9i Developer Suite to build applications, and Oracle9i Application Server to run them, the Oracle Internet Platform is a complete solution for building any type of application and deploying it to the Web. These Oracle tools provide a scalable and highly available infrastructure that enables customers to easily accommodate growing user populations.

1.2.3 Integrated

Oracle9i Application Server is simply the best application server for the Oracle8i database and applications built with Oracle development tools. By leveraging a common technology stack, Oracle9i Application Server can transparently scale an Oracle database by caching data and application logic on the middle tier. Additionally Oracle9i Application Server inherits much of its robust scalability and availability features from the mature technology of Oracle8i.

1.3 Deploying Applications with the Oracle Internet Platform

The Internet has moved application architectures from a typical 2-tier client/server model to a variety of multi-tier deployments that host presentation and business logic on the server. The advantages inherent in this move are many:

• Deployment of new versions is easier, faster, and cheaper. To roll out a Web application, simply give users the application's URL. This distribution method reduces the time, cost, and complexity of deploying applications to a large or geographically-dispersed user base by eliminating the need to install application software on each user's desktop machine.

• Centralized distribution means lower total cost of ownership. Web deployment dramatically reduces the cost of administration, maintenance, and network while increasing information accessibility. Instead of multiple outposts providing system administration support, system maintenance and administration is performed from one central location. With Web deployment, application complexity moves off of each user's desktop and onto centrally located, professionally managed application servers. This makes possible professional management of your site on a small number of servers, vastly simplifying, accelerating, and standardizing maintenance tasks and dramatically lowering costs.

• Standards-based development means better integration. Oracle application development adheres to the same existing and emerging standards used all across the World Wide Web. These include Java, Enterprise JavaBeans, HTML, XML, CORBA, HTTP, HTTPS, and the like. Common language means easier and faster integration of newly or separately developed applications.

• Component-based development means increased productivity, easy maintenance, and reusability. Customize applications rapidly in response to the different requirements of a diverse audience. Business developers need only alter affected components and not the entire application. Commonly applied components can easily be reused in other applications. These are just some of the ways organizations are able to respond in "Web time" to user requirements.

The Oracle Internet platform is the lowest-cost deployment platform because it simplifies the delivery and management of applications:

• Server scalability means fewer servers for lower cost and easier management.

• Server-side application and data processing mean efficient network utilization.

• On the client side, all you need is a browser: there are no incremental software costs for desktops connecting to a database.

1.4 Oracle9i Application Server

Oracle9i Application Server is an important component of the Oracle Internet Platform. It provides the broadest range of middle tier services of any vendor, supporting portal and transactional application development, flexible deployment, enterprise integration, and business intelligence services all out-of-the-box.

Oracle9i Application Server enables its customers to bring new and existing applications to run on the Internet quickly and at low cost. It offers performance benefits through its scalability, availability, and load balancing services.

1.4.1 Scalability

Oracle9i Application Server enables high scalability of Web applications in three central ways:

• It runs on a broad set of hardware and operating systems, enabling users to upgrade their hardware without changing their applications.

• It can boost the scalability of the system by caching database data and stored procedures on the middle tier, allowing back-end databases to serve greater numbers of concurrent users.

• It can be deployed on single-node or multi-node clusters to scale both stateless and stateful applications.

1.4.2 Availability

Clients running applications on Oracle9i Application Server will ideally perceive little or no loss of service during many types of hardware and software outages. Oracle9i Application Server provides a number of features and mechanisms designed to keep your system available despite limited server failures:

• It has no single point of failure.

• It isolates sessions to minimize impact of session outage.

• It can automatically detect failure, reroute connections, and restart processes.

1.4.3 Load Balancing

With load balancing, when you approach the limits of your current hardware, rather than either upgrading or throwing out a machine, you can just add more nodes and spread the increasing load across several machines.

Effective load balancing helps maximize scalability by enabling a system to make efficient use of its processing resources. Oracle9i Application Server load balances efficiently both between threads and processes on a single node and between nodes in a multi-node deployment. Further, Oracle9i Application Server can be deployed on a centralized collection of host machines, known as middle-tier server farms.

1.4.4 Oracle9i Application Server Services

Oracle9i Application Server consists of a set of services and utilities that can be used to implement applications in a distributed environment for scalability and reliability. These include:

• Communication services

• Presentation services

• Data management services

• System services

• Business logic services

1.4.4.1 Communication Services

Oracle9i Application Server communication services handle requests coming in to the server. Services are provided through a combination of Oracle HTTP Server and Oracle HTTP Server Modules. The Oracle HTTP Server is powered by Apache, the de facto standard Web listener on the Internet. Apache serves over 60 percent of the world's Internet sites, offering a robust, scalable technology. Oracle HTTP Server Modules are plug-ins to the HTTP Server that extend its functionality by offering native services or by dispatching requests to external processes.

1.4.4.2 Presentation Services

Oracle9i Application Server presentation services handle output of graphical representation, often in the form of HTML. They support a variety of different ways to generate client presentation, from low-level programming via scripts, through high-level frameworks via Oracle Portal. These services include support for Oracle Portal, Apache JServ, OracleJSP, PL/SQL, and Perl.

1.4.4.3 Data Management Services

To reduce the load on the back-end database instance, and to avoid network round-trips for read-only data, Oracle9i Application Server includes Oracle 9i Application Server Cache.

Oracle 9i Application Server Cache is a read-only data and application cache that resides on the middle tier as a component of Oracle9i Application Server. It improves the performance and scalability of applications that access Oracle databases by caching frequently used data and stored procedures on the middle-tier machine. Oracle 9i Application Server Cache has enabled some applications to process several times as many requests as their original capacity. It's ability to improve performance is based largely on two factors:

• Processing database queries on the middle tier reduces time spent sending and receiving data over the network.

• Reducing the load on the database server tier means that existing databases can support more users.

Applications that stand to benefit the most from Oracle 9i Application Server Cache include those that access data from an Oracle database over a network; those that have significant dynamic read-only content; and those that contain discrete tables with low volatility.

1.4.4.4 System Services

To provide system management and security services, Oracle9i Application Server includes Oracle Enterprise Manager (OEM) and Oracle Advanced Security. These services offer a comprehensive management framework for your entire Oracle environment along with network security via Secure Sockets Layer-based encryption and authentication facilities.

OEM provides an integrated solution for centrally managing your Oracle platform. It includes a GUI console, Oracle Management Services, Oracle Intelligent Agents, and administrative tools.

Use OEM to:

• Monitor and respond to the status of your Oracle products and third-party services

• Schedule activities on multiple nodes

• Monitor networked services for events

• Organize your view of server components and services into logical administrative groups

• Measure application performance (through OEM's Oracle Trace)

1.4.4.5 Business Logic Services

Oracle9i Application Server provides several ways to develop business logic, using both Java development and high-level, model-driven techniques. This includes support for such Java technologies as Java 2 Platform, Enterprise Edition (J2EE); Enterprise Java Beans (EJB); Oracle Business Components for Java (BC4J); as well as rich, GUI-oriented approaches, using Oracle Forms Developer and Oracle Reports Developer.

1.5 Deploying Forms with Oracle9i Application Server

Using Oracle9i Application Server Form Services, you can run applications built with Oracle Forms Developer over the Internet or your corporate intranet, without compromising either functionality or richness of interface.

Build new applications specifically for Web deployment, or take your existing forms, menus, and libraries currently deployed client/server and move them to Web deployment, almost without change.

There are many additional benefits to be realized from using Oracle9i Application Server Forms Services. Here are just a few:

• Extensible optimized Java client. Business developers can incorporate JavaBeans and reuse Java classes in their Forms applications. This extends the client Java applet portion of Form Services architecture and enables business developers to build really sophisticated user interfaces. These interfaces leverage the strengths of the Java language and allow for the reuse of Java components.

• Automatic scalability over any network. Oracle Forms Services natively delivers load balancing capabilities. Load balancing efficiently distributes client requests across available system resources. It is optimized for corporate intranet, extranet, and Internet deployment. You can use the application on LAN, WAN, and dial-up network architectures.

• Built-in optimizations for high performance. Oracle Forms Services has many built-in optimizations that work around the two main constraints that are typical in three-tier architectures: network bandwidth and latency between the client and application server.

  Forms Services reduces network bandwidth by intelligently condensing the data stream using advanced algorithms.

  One way Oracle Forms Services tackles latency is through Event Bundling: When a user navigates from item A to item B (such as when tabbing from one entry field to another), a range of pre- and post-triggers may fire, each of which requires processing on the server. Event Bundling "gathers" all the events triggered while navigating between the two objects and delivers them to the server as a single packet for processing. When navigation involves traversing many objects (such as when a mouse click is on a distant object), Event Bundling gathers all events from all of the objects that were traversed and delivers them as a single network message to the server.

• Integration with a highly productive, declarative Rapid Application Development (RAD) tool. The Forms Services in Oracle9i Application Server were developed specifically to serve Oracle Forms applications. This simplifies the transition from development to deployment by eliminating time-consuming issues that can arise when integrating applications and servers created with tools from disparate vendors.

1.6 How This Guide Can Help

When you choose to deploy applications to the Internet, there are many decisions to be made as to how you will go about it. This guide provides information about those decisions and offers suggestions and methods for configuring your system for Web deployment of your applications.

We provide:

• An overview of the Form Services component of Oracle9i Application Server architecture

• A guide for installing and configuring the Form Services component in a variety of Web deployment scenarios

• A section on migrating your legacy client/server applications to the Web

• Sections on capacity planning and load balancing to help you set up multiple servers that work and communicate together to share growing workloads

• Sections on network and security considerations

• Sections on application design considerations and tuning for optimizing the performance of your Web applications