Performing a Site Survey34 Netscape Directory Server Deployment Guide • December 2001Mastering data in non-directory applications makes the most sense if you canidentify one or two applications that you already use to master your data, andyou want to use your directory only for lookups (for example, for onlinecorporate telephone books).How you maintain master copies of your data depends on your specific needs.However, regardless of the how you maintain data masters, keep it simple andconsistent. For example, you should not attempt to master data in multiple sites,then automatically exchange data between competing applications. Doing so leadsto a “last change wins” scenario and increases your administrative overhead.For example, suppose you want to manage an employee’s home telephonenumber. Both the LDAP directory and a human resources database store thisinformation.The human resources application is LDAP enabled, so you can writean automatic application that transfers data from the LDAP directory to the humanresources database, and vice versa. However, if you attempt to master changes tothat employee’s telephone number in both the LDAP directory and the humanresources data, then the last place where the telephone number was changedoverwrites the information in the other database. This is acceptable as long as thelast application to write the data had the correct information. But if thatinformation was old or out of date (perhaps because, for example, the humanresources data was reloaded from a backup), then the correct telephone number inthe LDAP directory will be deleted.Determining Data OwnershipData ownership refers to the person or organization responsible for making sure thedata is up-to-date. During the data design, decide who can write data to thedirectory. Some common strategies for deciding data ownership follow:• Allow read-only access to the directory for everyone except a small group ofdirectory content managers.• Allow individual users to manage some strategic subset of information forthemselves.This subset of information might include their passwords, descriptiveinformation about themselves and their role within the organization, theirautomobile license plate number, and contact information such as telephonenumbers or office numbers.• Allow a person’s manager to write to some strategic subset of that person’sinformation, such as contact information or job title.
