An Application Server is software that provides services to support Web-based applications that tie end users to corporate databases. It acts as a middleman between Web browsers and the database servers, so firms don't need to install high-maintenance Windows applications at the user end. For example, you want to use the Web to let internal users or your customers look at corporate information. But you want to keep installation at the user end simple, and you don't want just anyone to get into your databases.

That may be where an application server enters the picture. These software packages, typically written in Java programming language for use on Windows NT-based systems, act as go-betweens linking browser-equipped end users to the databases that hold the information they need to access.

Application servers manage the process of connecting users to that data. They set up an application session for each user, check identifications, gather requested information from the appropriate database and build the data in to a Web page to serve directly to the users

The software gives you all the generic things that you need to have between the page in a [user's] Web browser and what you have in your database. That's using an application server to make a database of real estate information available to customers via the Internet. What that means is that little or no application code needs to be installed at each end user's PC, making it possible to develop thin-client applications — server-based software that runs in a Web browser and requires minimal desktop support

The goal of application servers is very simple: to have thin clients everywhere. All of the code required to run an application is basically built in to the server software.

Application server software packages also provide application management services such as monitoring system performance to sniff out bottlenecks. And they can be tied together to build large-scale applications that require multiple servers to meet the demands of users for data

Adding Complexity

Companies looking to build more complex applications can connect application servers to separate software servers that process orders and other transactions and that distribute reusable chunks of application code [called objects] to users. AHC, along with its vendor partners, can combine these technologies into a single package

The use of application servers is still low. For example, a 1998 survey of 25 Fortune 1,000 companies doing business globally shows that only four of the companies surveyed had installed packaged application servers.

Many Web applications are still in pilot mode, and it takes a while to even figure out that you need [the] services that application server software provides. Prices ranging from $15,000 to $100,000 can also be a barrier, he adds. But he estimates that the percentage of users with application servers will nearly double this year.

An Application server's role in a system

It creates a user session for each customer that's dedicated to handling requests [for data] from that particular person. From there, it handles interactions such as transferring and changing Web pages, doing security control and providing database connectivity. If you're going to be offering something where the data changes on each Web page, you pretty much have to have that session management [capability]. The users aren't coming in and accessing static Web pages. You have to be able to execute the queries and retrieve the information they're after

Possible benefits from an application server

One of the big things is it provides a much thinner client. Even if you have some Java source code that you distribute to the users, it's very little. We're looking at around 1,000 just to begin with, and maybe 10% to 20% of that concurrently. But our total customer base is about 20,000 people, and we're thinking that five years down the road, this will be one of our main vehicles for offering products

How one application server works:

1. A real estate professional links his or her browser to a site and is connected to the NT-based application server.

2 . The application server establishes a user session and crosschecks log-in information against a database on a separate NT-machine.

3 . A custom Web page is created by the application server, enabling the user to query a company's proprietary Unix-based database

4 . Queries are sent to the application server, which establishes a link to the Unix machine and retrieves the requested data.

5 . The application server collects the data and builds a new Web page for the user

6. Requests for street maps are redirected by the application server to a third NT machine, which uses a separate Web server to produce them.

Oracle(R) JServer, the server-side Java engine incorporated into the Oracle8i(TM) database that provides an enterprise platform on which to deploy e-business applications is a prime example of an application server. Attracted by the scalability, performance and stability of the Oracle JServer engine, scores of Oracle partners have moved to support Oracle JServer with applications, components, tools and infrastructure products.

As more companies migrate from client/server to Internet computing, Java-the language of the Internet-has rapidly emerged as the standard language for writing database applications. Because it enables Java-based applications to run directly in Oracle8i, Oracle JServer improves Java-based application performance through the application's proximity to the data it is accessing. In addition, the tight integration of Java into the database extends Oracle8i's scalability, high availability and security benefits to Java-based applications. In fact, recent scalability tests, conducted at Sun Microsystems, showed that Oracle JServer was capable of supporting almost 100 times more concurrent users than a standard HotSpot VM running outside the database. In the same benchmark, Oracle JServer also exhibited linear response times from1 through 5,000 users.

"Oracle JServer sets a new standard for server-side Java scalability and reliability," said Jeremy Burton , vice president of server marketing at Oracle. "Broad industry support from partners and customers is making Oracle JServer the overwhelming choice for deploying e-business applications written in Java."

Partner Endorsements

Committed to doing the bulk of its new development in Java, MapInfo Corporation has leveraged the power of Oracle8i's JServer for its 100 percent Pure Java mapping server, MapXtreme, and has integrated its flagship products with Oracle8i to take advantage of the proven benefits of its integrated Java Virtual Machine.

"Oracle's JServer for Oracle8i sets Oracle apart from all other vendors in terms of functionality, performance and extensibility," said Dwight Cheu, director of product development at MapInfo. "Having worked with Oracle closely to integrate MapInfo spatial and mapping components with Oracle8i, we are now able to deliver new Internet-based data analysis applications that support thousands of users across an enterprise. The Java-based solution comprised of MapInfo and Oracle Spatial depends on, and is enhanced by, Oracle JServer."

For application development tool vendor Symantec, Oracle JServer allows Symantec users to easily develop Java-based applications that can run directly within Oracle8i. "Symantec's VisualCafe enterprise Suite integrates with Oracle JServer to make it easier than ever to build highly scalable, dynamic Web applications in Java," said Mansour Safai, vice president of Symantec's Internet Tools Division. "The combination of VisualCafe and Oracle8i with Oracle JServer provides a complete and compelling development solution where developers in every industry can build once and deploy to thousands to accelerate the development of database-enabled Java applications."

The open standards supported by Oracle8i help ensure IONA Technologies' customers that the applications they build on either company's object request broker (ORB) can interoperate successfully. "Collaboration between IONA and Oracle ensures that business objects will be portable, scalable and reusable, capable of being deployed on any tier of an n-tier model," said Conor Halpin, vice president of strategic alliances at IONA Technologies. "IONA's work with Oracle underlines our commitment to making software work together. IONA is once again delivering on this commitment by simplifying application development, providing software functionality and, with Oracle JServer, introducing a powerful solution for enterprise development in Java."