NetWare Directory Services

3-9

Understanding Management Features

Directory Synchronization

When changes are made to objects within a partition, those changes are

automatically sent to all other replicas of that partition. This ensures that the

global Directory database remains consistent. Only changes are sent to other

replicas. For example, if a user changes a phone number, only the new phone

number is sent, not the entire User object.

An NDS database is a “loosely consistent” database. As changes occur, all

replicas of a partition do not always contain exactly the same information at

every instant. In fact, the contents of the replicas most likely vary slightly at

any given time. However, these replicas eventually converge to a consistent

state once the changes are distributed to all replicas.

Some changes are sent immediately to other replicas, such as changes to a

user’s password. Other, less critical changes, such as a user’s last login time,

are collected locally for a short period of time before being sent out to the

network.

Every partition maintains a record of its replicas. The locations are stored in

the partition’s replica property, with one entry for each replica. The

collection of replica properties of a partition forms a list of the replicas,

sometimes called a replica ring or replica list.