I n f o r m i x

Informix Web Integration

Option for Informix

Dynamic Server

Abstract

Web Integration OptionTM for Informix Dynamic ServerTM provides applica-

tion developers with the ability to generate Web-enabled applications that can

dynamically access any information stored within Informix databases. This

paper reviews the components required for developing and managing Web-

enabled database applications, and then examines how the Informix Web

Integration Option can ensure successful development and management of

these applications.

Table of Contents

Introduction 1

Web-Enabled Database Application Architecture 3

Middleware 4

Common Gateway Interface 4

Other Middleware Solutions 5

Informix’s Web Integration Option 6

Open, Robust Development Environments 6

Enhanced Manageability 7

High Performance and Scalability 7

Persistent State 8

Secure Environment 8

Browser and Server Independence 8

Informix’s Web Integration Option: Technical Overview 9

Architecture Overview 9

Application Management 10

Connection and Session Management 11

Components of the Web Integration Option 12

HTML Tag Extensions 12

Web-DB Publisher 12

Informix’s Web Integration Option API 13

Integration with Web Servers 13

Web Integration Option Advantages 14

Centralized Management 14

Object-Relational Extensions 14

Delivering Unsurpassed Performance 15

Conclusion 17

Introduction

The World Wide Web has proven to be an excellent medium for businesses

to disseminate information, both internally and externally. An external Web

site enables a company to publish marketing literature to inform and educate

customers, partners, and suppliers about its company and product offerings.

An intranet Web site lets a company distribute a wide range of company-spe-

cific information to its employees such as employee directories, sales material,

marketing plans, etc. The Web provides businesses with a low-cost delivery

mechanism for publishing a wide variety of information.

As the technology evolves, companies are beginning to utilize the Web as

a medium for their day-to-day business transactions. For example, companies

are creating interactive, customizable applications that use the Web to let cus-

tomers buy products and services. This innovative method of using the Web

not only allows companies to address existing markets through new means,

but also enter into new market segments, thus increasing business revenues

and expanding market share objectives.

To unlock the potential of the Web, Informix offers Informix Dynamic

Server and the Web Integration Option. Optimized for both publishing and

transaction-based environments, the Web Integration Option offers a set of

products and services that together with Informix Dynamic Server provide a

solution for allowing today’s businesses to create truly mission-critical Web

applications across the distributed enterprise.

Unlike all other Web solutions which store Web applications as flat files

and scripts in the file system, the Web Integration Option stores all of the

Web application content—including HTML files, Web page templates, and

multimedia content such as text, images, maps, and photos—within Informix

Dynamic Server. By storing all the Web application content within the data-

base, developers can manage the application as it grows in size and complexi-

ty, ensuring the dynamic delivery of information to users. By managing all

the content in the database, organizations can take advantage of the power of

Informix Dynamic Server—and better manage, query, and secure their Web

data.

A critical component of Informix’s Web Integration Option is the ability

to rapidly develop Web applications that can dynamically access the informa-

tion stored within any Informix database or legacy application in your enter-

prise. Informix’s Web Integration Option provides development and run-time

1

components that integrate the Web server with Informix Dynamic Server. By

utilizing this robust interface, developers can quickly and easily generate Web

applications that incorporate data retrieved dynamically from Informix

Dynamic Server.

This paper discusses in detail Informix’s Web Integration Option. It first

explores the architecture of typical Web-enabled database applications and

how Informix’s Web Integration Option can ensure successful development of

such applications.

2

Web-Enabled Database ApplicationArchitecture

To build a Web-enabled database application, the following components

are necessary:

• Web client

• Web server

• Middleware

• Database server

The Web client is a Web browser such as Netscape Navigator or

Microsoft Internet Explorer. The Web server is any HTML-based server such

as Netscape FastTrack or Enterprise Server, or Microsoft Internet Information

Server. An end user can spawn a database application through the Web

browser that communicates with the Web server through the Internet via

hypertext transport protocol (HTTP).

The middleware is responsible for managing communication and provid-

ing application services between the Web server and the database server. The

middleware software calls external programs or “scripts” that act as the “trans-

port and layout mechanism” between the Web server and the database server.

This script constructs the query, passes the query to the database, and formats

the output as an HTML page. The Web server then returns the HTML page

to the Web browser to display the information to the end user.

The database server manages the data residing within the database.

3

Web C l i en t

h t t p h t t p

I n t e rne t/ In t r ane t Web Se r ve r M idd l ewa re ( CG I ) Da taba seSe r ve r

F i g u r e 1 :

Components of

Web-Enabled

Database

Applications

Middleware

There are a number of middleware solutions in the market today. The most

popular middleware used today is the common gateway interface (CGI).

Other solutions include ISAPI from Microsoft and NSAPI from Netscape.

Common Gateway Inter face

CGI is an interface used for interfacing external applications with a Web serv-

er. Applications can use CGI as a vehicle to communicate with the database,

transmit information to the server, and receive results for display on the

client. This technique provides a simple mechanism for basic database con-

nectivity.

While CGI offers a simple way to connect to a database, it does have

some limitations. First, CGI applications are not persistent. Each time the

CGI program is accessed through the Web server the CGI program starts up,

performs its processing, then exits. Because the CGI application is restarted

with each request, the database connection must be re-established each time.

As a result, applications that require a persistent database connection have to

use complicated techniques to maintain state between client requests and

waste a lot of bandwidth trying to maintain them.

CGI also suffers from performance problems, especially in multiuser

applications where multiple database connections are required. In addition to

the persistence problem discussed above, CGI applications cannot be shared

by multiple client requests. Even if a CGI application is running when a new

request comes in, a new copy of the CGI application is started. As more con-

current requests are made, more concurrent processes are created on the serv-

er. Creating an application process for every request is time-consuming and

requires a large amount of memory. Additionally, it restricts the resources

available for the application itself, thereby slowing down performance and

increasing wait time.

Another problem with CGI is the fact that there is no language associat-

ed with it. To provide a Web application with access to a database, a develop-

er must write a script using languages such as PERL or Tcl—languages that

can lead to performance problems. Many application developers simply do

not have the knowledge or the time to create and maintain these CGI scripts

and HTML files. Most businesses do not have this expertise in house.

Finally, manageability is a key concern with CGI. Since developers have

to write separate scripts in order to connect to the database, these scripts and

files may be spread out across the network, hence become very difficult to

manage and control. Additionally, security is of a special concern. Since a

4

CGI program is executed on a company’s Web server, special precautions are

needed to ensure security. These precautions may include moving CGI pro-

grams to a special directory. This creates additional work for both program-

mers and Web masters.

Other Midd leware So lut ions

To overcome the limitations described above, both Microsoft and Netscape

came out with their own middleware solutions: Microsoft with ISAPI and

Netscape with NSAPI. These APIs provide better performance, enable devel-

opers to more easily develop complex applications, and offer better protection

and security. These solutions, however, still rely on middleware scripts to inte-

grate with the database and therefore have many of the same performance

problems as CGI.

5

Informix’s Web Integration Option

To address the limitations and the incompatibilities of CGI, NSAPI, and

ISAPI, Informix offers the Web Integration Option for Informix Dynamic

Server. The Web Integration Option lets customers maximize the potential of

the Web by allowing them to create robust Web enabled database applica-

tions. It offers state-of-the-art technology to bring high performance and

enhanced manageability. Additionally, the Web Integration Option supports

all popular Web servers, operating systems, and Web browsers, and is com-

patible with other middleware solutions such as CGI, NSAPI, and ISAPI.

Combined, these capabilities allow customers to build dynamic, interactive

applications that respond to the growing sophistication of users.

In use om over 1,000 applications, Informix’s Web Integration Option

lets developers create intelligent Web applications that incorporate data

retrieved dynamically from Informix databases. The type of data retrieved by

the application can be any datatype supported by Informix database servers,

including traditional alpha-numeric datatypes, as well as HTML pages,

images, documents, spreadsheets, presentations, maps, audio, or any user-

defined datatypes.

Informix’s Web Integration Option is based on industry-leading technol-

ogy, and delivers:

• rapid application development;

• enhanced manageability;

• open, robust development environments;

• persistent application state;

• unsurpassed performance and scalability;

• a secure environment; and

• Web browser and server independence.

Combined, these capabilities allow customers to build dynamic, intelli-

gent Web applications.

Open, Robust Deve lopment Env i ronments

Informix’s Web Integration Option provides an open development environ-

ment for creating Web applications. Unlike CGI, which requires developers

to write proprietary scripts to create Web applications, the Web Integration

Option offers two industry-standard development methods to address the dif-

ferent needs of Web application developers.

6

The first development method is ideal for Web application developers

that are publishing dynamic information on the Web. Through a small col-

lection of Informix HTML tag extensions, Web authors can create applica-

tions that dynamically construct Web page templates from Informix Dynamic

Server and present it to the end users. The Web Integration Option also lets

users create their own customized and reusable tags to perform specialized

tasks. Through the use of these HTML tags, Web authors are able to create

powerful applications quickly and easily without resorting to programming.

The second method is for applications that are more transaction-based or

client/server oriented. To extend the functionality of the application, this

method lets developers create customized Web applications through a pro-

grammatic API. The API offers a collection of basic services, such as connec-

tion and session management, that is automatically incorporated within any

customized Web applications created by the developers to ensure performance

and persistence.

Informix’s Web Integration Option supports applications developed in

many programming languages, including C, C++, and Java. This flexibility

lets developers port existing database applications to the Web, as well as

develop new Web-enabled applications using more sophisticated languages.

Enhanced Manageabi l i ty

Informix’s Web Integration Option eliminates the problems associated with

manageability by storing the entire Web application content inside the

Informix database. This ensures that developers can gain easy access to all the

content associated with the Web application, allowing them to efficiently

manage the application as it grows in size and complexity. They can also take

advantage of all database features for Web applications, including backup and

recovery, replication, data and process modeling, and ad hoc querying.

High Per formance and Sca labi l i ty

Informix’s Web Integration Option lets developers create applications that

deliver the highest performance possible. This is accomplished through the

execution of SQL statements embedded directly within the HTML pages,

providing applications with a direct access path to the database for fast data

retrieval. The Web Integration Option also includes a set of API services to

support complex Web applications that require extremely fast response times.

Unlike CGI, a copy of the application does not have to be invoked with

each client request. Web Integration Option applications can be shared

among multiple client requests to spare the system overhead of restarting the

application. The number of Web Integration Option applications started is

7

8

configurable by the administrator to meet the needs of the user load. To

ensure performance and scalability, Informix’s Web Integration Option pro-

vides a load-balancing algorithm to distribute the client requests across all the

available applications.

Tightly integrated with Informix Dynamic Server, the Web Integration

Option takes full advantage of Informix’s efficient multithreaded database

architecture and its parallel processing capabilities. Therefore, as the number

of Web database application users and the amount of Web page processing

increases, the Informix Dynamic Server will automatically scale across all

available system resources to deliver the highest performance possible.

Pers is tent S tate

Informix’s Web Integration Option provides a set of session and connection

management services to maintain a persistent database connection. When the

user starts a session by requesting the first HTML page of the application, the

Web Integration Option generates a session identifier and forks the applica-

tion. When the HTML page is returned to the Web browser, the session

identifier is also returned. This session identifier is then used when the user

requests the second and subsequent HTML pages from the application. With

the Web Integration Option, Web authors and developers do not have to

resort to creating complicated scripts in order to maintain state between

client requests.

Secure Env i ronment

The Web Integration Option offers a secure environment for developing

Web-enabled applications. This is achieved through integration with Web

server software. This integration utilizes all the native security mechanisms of

Informix Dynamic Server. You can even use existing database security

schemes, in your application.

Browser and Server Independence

Informix’s Web Integration Option offers an open architecture that is inde-

pendent from vendor-specific Web browsers and Web servers. Any Web

browser can access database applications via any Web server. Independence

from vendor-specific Web browsers is critical because the end user’s browser is

not typically under a developer’s control. Similarly, independence from the

Web server is important, to give you the flexibility to take advantage of tech-

nological innovation.

Informix’s Web Integration Option:Technical Overview

This section provides a detailed discussion of the Web Integration Option

architecture and its product components.

Arch i tec ture Overv iew

As mentioned in the previous section, the CGI architecture requires a devel-

oper to write scripts in PERL, Tc1, or C. These scripts construct the query,

pass the query to the database, and format the output into an HTML page.

Informix’s Web Integration Option eliminates the need for creating

tedious scripts. Instead, developers are provided with tools for creating intelli-

gent HTML pages directly within the database. These HTML pages, called

Application Pages (or AppPages), execute Structured Query Language (SQL)

statements dynamically, format the results inside HTML, and return the

resulting Web page to the end users. Figure 2 illustrates the architecture of

the Web Integration Option:

Figure 2 illustrates the CGI implementation of the Web Integration Option.While it can work with CGI, the Web Integration Option addresses theshortcomings of CGI previously identified.

Recall that a new CGI application must be spawned for each

client/browser connection. Typically, this extreme overhead is detrimental to

performance. To minimize this overhead, the Web Integration Option creates

a featherweight CGI process called the WebDriver. It is invoked when a URL

request is sent from the Web browser to the Web server. Upon receiving the

request, the WebDriver generates a unique session identifier and sends the

request to the Web Integration Option application.

9

Web B rowse r

h t t p h t t p

I n t e rne t/ In t r ane t Web Se r ve r Web App l i c a t i onSe r v i c e s

Da taba se

AppPage

tag tag

WebDr i ve r

Web I n t eg ra t i on

Op t i on

F i g u r e 2 :

Informix Web

Architecture

The Web Integration Option application is a persistent application that

does not terminate after each request. Developed using Informix’s Web

Integration Option API, the Web Integration Option application provides

important Web application services such as connection and session manage-

ment. Companies that need specialized application services can create

customized Web applications through the Web Integration Option API.

To ensure that all customized Web applications deliver a persistent

application environment and the highest performance possible, the Web

Integration Option API automatically incorporates all Web application

services provided by the Web Integration Option application within all

customized Web applications.

When the Web Integration Option application receives a request from

the WebDriver, it connects to the database and executes a function called

WebExplode. WebExplode executes the queries within the Web pages and

formats the subsequent results. WebExplode then returns the resulting Web

page to the WebDriver, which forwards the results to the Web browser.

Appl i cat ion Management

The Web Integration Option provides a wide range of application manage-

ment services. Informix’s Web Integration Option lets developers customize

their Web applications using information stored within a wide range of

sources, including the configuration file, the Web server environment, URLs,

HTML forms, Web application variables, and the underlying database shell.

This flexibility enables customers to easily customize applications to their

businesses without any CGI programming.

As discussed earlier, the behavior of the Web Integration Option applica-

tion is configurable. For example, the state information for client requests

should not be maintained infinitely. There is a default time-out value for

browser sessions which can be changed by an administrator. For scalability

purposes, administrators can define the number of Web Integration Option

applications to run. The WebDriver will distribute client requests across the

available Web Integration Option applications utilizing a load-balancing algo-

rithm. This load balancing provides the basis for an extremely scalable and

high-performance solution.

To further promote high performance, frequently accessed pages and

objects are cached in memory. Additionally, the WebDriver and the Web

Integration Option application provide error handling and logging capability

as well as event management.

The WebExplode function provides the services to manage the AppPages.

These services include the retrieval of AppPages and objects from the database

10

and expanding the AppPages from the embedded tags to perform special

tasks. Additionally, it also provides services for interpreting AppScript macro

language and using the included AppPage schema to manage application con-

tent such as HTML pages, documents, images, user-defined tags, etc.

Connect ion and Sess ion Management

The Web Integration Option ensures application persistence by offering a

collection of connection and session management services. Since the Web

Integration Option application is a shared application, multiple client

requests are funneled into one or more Web Integration Option applications.

The number of the Web Integration Option applications is configurable to

meet the scalability needs of applications. To track relationships between users

and applications, the WebDriver generates a unique, secure session identifier

for each client. This session identifier is used for the entire session to recog-

nize new requests from the same client and provide that information to the

Web Integration Option application.

Based on the application, the Web Integration Option application will

maintain the value of application variables and database connections from

one browser request to the next. The WebDriver and the Web Integration

Option application share the session information using a shared memory seg-

ment, much like Informix Dynamic Server uses shared memory.

11

Components of the Web IntegrationOption

Informix’s Web Integration Option provides the following components for

building Web applications:

HTML tag extensions

• Web-DB Publisher

• Web Integration Option API

• Integration with Web servers (NSAPI, ISAPI, and CGI)

HTML Tag Extens ions

Within the AppPages, developers and sophisticated Web authors can incorpo-

rate HTML tag extensions, called AppScript, to create dynamic Web applica-

tions without resorting to programming. This set of 5 tags give Web authors

a simple way to access application logic and content stored in Informix

Dynamic Server. The content can include dynamically constructed or static

HTML documents and associated multimedia content. Users benefit because

the Web Integration Option quickly extracts information from the database

for fast, personalized content delivery.

The tags that come with Informix’s Web Integration Option provide sup-

port for variables, branching logic, page format control, and SQL embedding.

Developers can use the tags provided by Informix, as well as create their own

tags to perform customized tasks. For example, Informix offers an HTML

extension tag that allows Web authors to temporarily return control from the

AppPage to the application so developers can execute specialized code in

order to achieve specific functionality, e.g. to connect to another database or

legacy application. In this way, developers have the flexibility to use the

AppPage to generate some parts of the page and use their own code for other

parts of the page.

Web-DB Pub l i sher

The Web-DB Publisher is a simple wizard which end users or administrators

can use to create Web-based reports of Informix database data. The wizard

consists of a small number of screens which walk the user through creating a

report. When executed, the report will be written in HTML format and

made available through the Web browser. These reports can be static or

12

dynamic. Dynamic reports will actually fetch values from the database when

the user accesses the report via its URL. Also, the Web-DB Publisher includes

a scheduling mechanism so that reports can be executed automatically, with-

out user intervention.

Web Integrat ion Opt ion API

High performance OLTP applications that cannot be implemented using

AppPages and HTML tag extensions alone can use the Web Integration

Option API library of C functions to ease development efforts. This set of

API services provides a framework for programmers to easily port or develop

client/server database applications on the Web. It provides a core set of ser-

vices to enable session and connection management, minimize overall devel-

opment time, and encapsulate the process of building HTML. Through this

interface, applications can establish connectivity with other distributed object

brokers such as IIOP, DCOM, and CORBA. Applications developed with

the Web Integration Option API library can utilize any programming lan-

guage such as C, C++, and Java.

In tegrat ion with Web Servers

Informix’s Web Integration Option offers optimized drivers for the Netscape

SuiteSpot Servers™ and the Microsoft Internet Information Server. This

integration enables the authorization and user authentication mechanisms to

be Informix database driven. As a result, all of the power and security of the

database can be applied, allowing for audit trails and access control over Web

server access at the object level. This allows the applications to take advantage

of rules and security mechanisms that already exist in the Informix database

application.

13

14

Informix’s Web Integration OptionAdvantages

Informix’s Web Integration Option offers the following advantages over com-

petitive products:

• Centralized management through storage of the entire Web

application content in the database and the ability to extend all database

functionality for Web applications (e.g., secure, manage, backup, recover,

and query).

• Tight integration with the Informix Dynamic Server to deliver

unsurpassed performance and scalability.

• Object-relational extensions within Informix Dynamic Server with the

Universal Data Option enable users to perform content-based queries on

Web pages.

Centra l ized Management

With Informix’s Web Integration Option, the entire Web application and

associated content is stored within the database. The content may include the

AppPages and all the multimedia content, including documents, images,

audio, video, etc. By storing the entire Web application content within the

database, developers can easily access, control, manage, backup, recover, and

query the entire Web application.

Competitive products store various components of their Web applica-

tions in distributed locations, such as within the file system or in a different

server. Decentralization of Web application content makes it difficult for

developers to determine the boundary of the application. As a result, develop-

ers waste an inordinate amount of time—that otherwise could be used for

application development—managing and tracking various application com-

ponents. They don’t get the full value of utilizing the database in the first

place, and it is very difficult for users to find the data they need.

Objec t -Re lat ional Extens ions

Informix Dynamic Server, with the Universal Data Option and Informix’s

DataBlade technology, allow customers to intelligently manage traditional

datatypes, as well as handle complex datatypes that are so common on the

Web, including video, sound, spatial, time-series, 2D and 3D, imaging, text,

and Web-based datatypes using standard SQL. By doing so, customers of

Informix Dynamic Server can fully exploit the database’s object-relational

extensions, allowing users to execute content-based queries on any type of

data stored within the database— while utilizing knowledge they already have

in their organizations.

Not only will the Web browser be able to query standard relational data,

but it will also be able to perform content-based searches on abstract

datatypes such as full text (including spreadsheets, presentations, and word

processing documents) sound clips, full-motion video, time-series, or geospa-

tial information. With Informix Dynamic Server, Universal Data Option,

customers can now create fully intelligent Web applications.

Today, competitive products lack the extensible foundation inherent to

Informix Dynamic Server. In 1991, Informix redesigned its database architec-

ture and built into the core product the foundation for extensibility. As such,

Informix competitors have to resort to inefficient approaches to extend the

capabilities of their core servers, making application development and man-

agement more difficult and costly.

Del iver ing Unsurpassed Per formance

Informix has tightly integrated the Web Integration Option with Informix

Dynamic Server. This tight integration enables Web application users to auto-

matically benefit from the performance and the scalability of Informix’s effi-

cient multithreaded database architecture. The database server’s ability to

scale across a large number of users and process a large amount of mission-

critical data is especially important given the nature of the Web environment,

where the number of users connected and the amount of data processed is

unpredictable and often quickly growing.

Unlike Informix’s Web Integration Option, many competitive products

do not provide the same high level of integration with their database server.

Some competitive products connect to the database via ODBC, hence it is

not tightly integrated with the database and cannot take advantage of the per-

formance and scalability of the database server. Other competitive products

are so tightly integrated with the Web servers such that scalability is limited

only to the scalability of the Web server. No other solution actually uses the

database to manage the Web application. They merely allow developers to put

a Web front-end on an existing client/server application.

Although a few competitive products offer integration with their databas-

es, performance may degrade as the number of connected users increases.

This is due to fundamental flaws within their database server designs. Unlike

15

Informix Dynamic Server, which manages user requests utilizing a light-

weight mechanism called threads, competitive database servers manage

requests at the operating system level. As a result, their applications cannot

support the level of performance and scalability necessary to handle large user

and processing loads.

16

Conclusion

Informix’s Web Integration Option offers customers a solution that is opti-

mized for Informix Dynamic Server. Ideal for both publishing and transac-

tion-based, and internal and external Web applications, Informix’s Web

Integration Option enables customers to create intelligent, customized Web

applications that incorporate data retrieved dynamically from Informix data-

bases. Unlike other competitive solutions, the Web Integration Option eases

the development of dynamic Web applications, by providing integrated Web

content and code management, high-performance, connectivity management,

secure access environment, and independence from Web browsers and

servers—offering customers a robust solution that not only addresses today’s

development needs, but also responds to future advancements in Web tech-

nology. In short, the Informix Web Integration Option allows you to manage

the Web for business advantage.

For more information on Web Integration Option, or any other

Informix products and services, contact your local Informix sales office or

visit the Informix Web site at www.informix.com.

17

©1997 Informix Software, Inc. The following are worldwide trademarks of Informix Software,Inc., Informix Corporation, or their subsidiaries,registered in the United States of America asindicated by “®” and in numerous countries worldwide: INFORMIX®, The Informix Logo®,IllustraTM, Dynamic Scalable ArchitectureTM DataBlade®. All other names or marks may be regis-tered trademarks or trademarks of their respective owners.

4100 Bohannon Drive

Menlo Park, California 94025

1 650 926 6300

World Wide Web: http://www.informix.com

Printed in U.S.A

. 12/97 000-21605-70

About In formixInformix Software, Inc., the world's data-base technology leader, provides innovativedatabase products that enable the world'smajor corporations to attain competitiveadvantage. Informix is widely recognized asthe technology leader for corporate com-puting environments ranging from smallworkgroups to very large parallel processingapplications. Informix's database servers,application development tools, superiorcustomer service, and strong partnershipsenable the company to be at the forefrontof major information technology solutionareas including data warehousing, OLTP,Web/content management, and distributedenterprise solutions.

For more information about Informixproducts and services, please contact thesales office nearest you, or visit us on theWeb at www.informix.com.

Regional Sales Offices

Asia/Pac i f i c65 298 1716

Canada (Toronto)416 730 9009

Europe/Midd le East/Afr i ca44 1784 422 000

Federa l703 847 2900

Japan81 3 5562 4500

Lat in Amer i ca305 265 7545

North Amer i ca800 331 1763650 926 6300

®