HP UX Direry Server 2.3.5 Considering a data master, 2.3.4 Determining level of service, Table, •Data owner, “Directory data characteristics”

•Data owner•Relationship to other directory data

Study each kind of data to include in the directory to determine what characteristics it shares with the other pieces of data. This helps save time during the schema design stage, described in more detail in Chapter 3 “Designing the directory schema”.

A good idea is to use a table, similar to Table 2-3 “Directory data characteristics”, which characterizes the directory data.

Table 2-3 Directory data characteristics

Data	Format	Size	Owner	Related to
Employee Name	Text string	128 characters	Human resources	User's entry
Fax number	Phone number	14 digits	Facilities	User's entry
Email address	Text	Many characters	IS department	User's entry

2.3.4 Determining level of service

The level of service provided depends on the expectations of the people who rely on directory-enabled applications. To determine the level of service each application expects, first determine how and when the application is used.

As the directory evolves, it may need to support a wide variety of service levels, from production to mission critical. It can be difficult raising the level of service after the directory is deployed, so make sure the initial design can meet the future needs.

For example, if the risk of total failure must be eliminated, use a multi-master configuration, where several suppliers exist for the same data.

2.3.5 Considering a data master

A data master is a server that is the master source of data. Any time the same information is stored in multiple locations, the data integrity can be degraded. A data master makes sure all information stored in multiple locations is consistent and accurate. There are several scenarios that require a data master:

•Replication among Directory Servers•Synchronization between Directory Server and Active Directory•Independent client applications which access the Directory Server data

Consider the master source of the data if there are applications that communicate indirectly with the directory. Keep the processes for changing data, and the places from which the data can be changed, as simple as possible. After deciding on a single site to master a piece of data, use the same site to master all the other data contained there. A single site simplifies troubleshooting if the databases lose synchronization across the enterprise.

There are different ways to implement data mastering:

•Master the data in both the directory and all applications that do not use the directory.

Maintaining multiple data masters does not require custom scripts for moving data in and out of the directory and the other applications. However, if data changes in one place, someone has to change it on all the other sites. Maintaining master data in the directory and

2.3 Performing a site survey 21