NELSON KINGDirectorial DebutRadiantOne puts LDAP in middleware to boost searches of multiple data sourcesAt heart, Radiant Logic’s RadiantOne is middleware. Yes, the software world is filling up with middleware, but this one is different. RadiantOne provides access to many kinds of databases for applications and direct viewing in a Web browser. These are conventional tasks for middleware, but as I found out during testing, what makes RadiantOne different is how it completes those tasks. RadiantOne is about using directories, specifically directories based on the lightweight directory access protocol (LDAP — see sidebar, “Lightweight Defeats Heavyweight”). In what Radiant Logic calls a Virtual Directory Server (VDS), RadiantOne stores and manages references to data in relational databases using LDAP. What does LDAP bring to this dance of data? The use of a new technology may have benefits that are not immediately apparent. Using e-commerce as an example, one of the biggest needs for business-to-business or consumer e-commerce is to qualify the customer (security, preferences, and so on). This information usually has multiple database sources, which makes searching and coordination difficult, especially under the demands of an interactive online context. Using an LDAP directory for this searching and coordination provides a structured environment that is much easier to configure and manage than other approaches. LDAP provides a standardized hierarchical format to organize the information, which RadiantOne visually presents in the extremely familiar Windows Explorer-style view of objects. Within the structure of an LDAP directory, RadiantOne stores references to data rather than the data itself. Radiant Logic calls the references — or addresses — Information Resource Locators (IRL), a kind of URL. An IRL is essentially a pre-configured query stored as an LDAP object. When an application (or a customer with a browser) requests a piece of information associated with an IRL, the IRL is converted to a SQL query and sent to the appropriate database server. RadiantOne processes the results and can return them as XML, LDAP, or SQL data sets. This system makes RadiantOne independent of the data content. As an LDAP server, RadiantOne can also connect with relative ease to other LDAP servers or interfaces, which usually will be the big, powerful, enterprise directories that are now shipping with major network platforms such as Novell (NetWare Directory Services) and Microsoft Windows 2000 (Active Directory). Between the directory and database connections, RadiantOne VDS can act as a hub for all kinds of application data management.
Schema DesignerIn some ways, using RadiantOne is easier than trying to describe it — often true with innovative products. Installation on Windows NT is painless and quick. Even without documentation (the beta version I tested had only sketchy documentation), most of the features of RadiantOne can be used by anyone familiar with database management. In addition to the Virtual Directory Server, RadiantOne includes tools that directory and database managers can use to set up the server environment. You can install the tools on Windows NT and 98 systems. The process starts with the DirectView Schema Manager. (See Figure 1.) This is the program where you analyze and prepare OLE DB/ODBC data sources, usually relational database systems, that an application requires. A schema extraction wizard does most of the work. (See Figure 2.) Because RadiantOne operates independently of the data and database server, you can use the Schema Designer to create relationships and views that are not part of the underlying database. When finished, the program creates an Objects and Relationships Graph (ORG) file, which the DirectoryView Designer uses in the next step. (See Figure 3.)
View DesignerThe DirectoryView Designer is another GUI Windows Explorer-like program where you refine views that will be used in applications. You use this tool primarily to determine what information is going to be available in a view and how RadiantOne VDS will present or output it. One of the aspects of RadiantOne that I found appealing was the use of an LDAP tree structure (see Figure 4) to allow users with a browser to drill down into data, even through complex relationships. This feature requires a small “SmartBrowser” plug-in that is downloaded at runtime. Not every application needs (or would allow) this kind of detailed examination of the data, but for some circumstances this is a powerful way to present relationships (for example, customer invoice and order items). Although I wasn’t able to stress the RadiantOne engine in a full production enterprise environment, I tested the beta release on both an intranet and Internet configuration, and the server performed well. RadiantOne is built on the Netscape Directory Server 4.0, which should provide both performance and scalability for the typical enterprise application. However, it should be clear that RadiantOne is not an application server. It doesn’t have session management or business-rule features, nor does it provide some performance features of many application servers such as connection pooling and data caching. It is arguable that the right way to organize enterprise information (at the highest level) is through a virtual directory. However, as we’re discovering, enterprise directories are not necessarily the easy way. Loading mission-critical information into an operating platform directory system (people, products, prices, and so on) is tricky and requires a great deal of forethought. RadiantOne LDAP directories are easier to implement, but still require careful planning. Once committed to directories (of all kinds) as the repository of enterprise information, it becomes almost imperative to have good tools to use those directories. RadiantOne should become a must-have program for network and database administrators working on applications in an enterprise environment with multiple heterogeneous directories. Whether it will also compete successfully with the many other middleware offerings that cater data to applications remains to be seen. RadiantOne has an attractive approach, but other features of middleware servers such as business-logic management and load balancing may be more important for general use. Judging from what I’ve seen in this first version of RadiantOne, VDS would be best used in conjunction with application servers such as Microsoft Site Server to produce applications that take advantage of the multiple data sources and manage the application environment.
Nelson King (nelsonking@earthlink.net) is a frequent contributor to Intelligent Enterprise. He has written nine books on database application programming and spends much of his time in the trenches of enterprise software development.
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