Netscape NETSCAPE DIRECTORY SERVER 6.1 - ADMINISTRATOR, Administrator'S Manual

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Overview of the Attribute Uniqueness Plug-In
480 Netscape Directory Server Administrator’s Guide • August 2002
If an update operation applies to an attribute and suffix monitored by the plug-in,
and it would cause two entries to have the same attribute value, then the server
terminates the operation and returns an
LDAP_CONSTRAINT_VIOLATION
error to the
client.
The attribute uniqueness plug-in performs a check on:
• A single attribute
• One or several subtrees
If you want to check uniqueness of several attributes, you must create a separate
instance of the plug-in for each attribute you want to check.
You can also configure how the attribute uniqueness plug-in operates:
• It can check every entry in the subtrees you specify.
For example, if your company,
example.com
, hosts the directories for
example_a.com and example_b.com, when you add an entry such as
uid=jdoe,ou=people,o=example_a,dc=example,dc=com
, you need to
enforce uniqueness only in the
o=example_a,dc=example,dc=com
subtree.
You can do this by listing the DN of the subtree explicitly in the uid uniqueness
plug-in configuration.
This configuration option is explained in more detail in “Specifying a Suffix or
Subtree,” on page 487.
• You can specify an object class pertaining to an entry in the DN of the updated
entry, and perform the uniqueness check on all the entries beneath it.
This option is useful in hosted environments. For example, when you add an
entry such as
uid=jdoe,ou=people,o=example_a,dc=example,dc=com
, you
can enforce uniqueness under the
o=example_a,dc=example,dc=com
subtree
without listing this subtree explicitly in the configuration, but instead, by
indicating a marker object class. If you specify that the marker object class is
organization
, the uniqueness check algorithm locates the entry in the DN
that has this object class (
o=example_a
) and performs the check on all entries
beneath it.
Additionally, you can specify to check uniqueness only if the updated entry
includes a specified object class. For example, you could specify to perform the
check only if the updated entry includes
objectclass=inetorgperson
.
This configuration option is explained in more detail in “Using the
markerObjectClass and requiredObjectClass Keywords,” on page 488.
If you intend to use the attribute uniqueness plug-in in a replicated environment,
refer to “Replication and the Attribute Uniqueness Plug-In,” on page 491.