This document describes the advantages of using a directory for directory integration.
Advantages of Using a Directory
An application-specific directory stores only the information needed by a particular application and is not accessible by other applications. Because a full-function directory service is complex to build, application-specific directories are typically very limited. They probably store only a specific type of information, do not have general search capabilities, do not support replication and partitioning, and probably do not have a full set of administration tools. An application specific directory could be as simple as a set of editable text files, or it could be stored and accessed in an undocumented, proprietary manner.
In such an environment, each application creates and manages its own application specific directory, which quickly becomes an administrative nightmare. The same e-mail address stored by the calendar application might also be stored by a mail application and by an application that notifies system operators of equipment problems. Keeping multiple copies of information up-to-date and synchronized is difficult, especially when different user interfaces and even different system administrators are involved.
What is needed is a common, application-independent directory. If application developers could be assured of the existence of a directory service, then application specific directories would not be necessary. However, a common directory must address the problems mentioned above. It must be based on an open standard that is supported by many vendors on many platforms. It must be accessible through a standard API. It must be extensible so that it can hold the types of data needed by arbitrary applications, and it must provide full functionality without requiring excessive resources on smaller systems. Since more users and applications will access and depend on the common directory, it must also be robust, secure, and scalable.
When such a directory infrastructure is in place, application developers can devote their time to developing applications instead of application specific directories. In the same way that developers rely on the communications infrastructure of TCP/IP and remote procedure call (RPC) to free them from low-level communication issues, they will be able to rely on powerful, full-function directory services. LDAP is the protocol to be used to access this common directory infrastructure. Like HTTP (hypertext transfer protocol) and FTP (file transfer protocol), LDAP has become an indispensable part of the Internet's protocol suite.
When applications access a standard common directory that is designed in a proper way, rather than using application specific directories, redundant and costly administration can be eliminated, and security risks are more controllable. For example, the telephone directory, mail, and Web application, as shown in the illustration "Several Applications Using Attributes of the Same Entry", can all access the same directory to retrieve an e-mail address or other information stored in a single directory entry. The advantage is that the data is kept and maintained in one place. Various applications can use individual attributes of an entry for different purposes permitting that they have the correct authority. New uses for directory information will be realized, and a synergy will develop as more applications take advantage of the common directory.
Storing data in a directory and sharing it amongst applications saves you time and money by keeping administration effort and system resources down. Many IBM applications also use directories to centrally store and share information. The number of applications that support LDAP directories is constantly increasing. For example, LDAP directory support, such as for authentication and configuration management, is provided in various IBM Operating Systems, IBM WebSphere Application Server, WebSphere Portal Server, Tivoli Access Manager, IBM Tivoli Directory Server, IBM HTTP server, Lotus Domino, and so on.
This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a client responsibility and depends upon the client's ability to evaluate and integrate them into the client's operational environment.