The slapd(8) daemon can use a variety of different overlays to alter
or extend the normal behavior of a database backend. Overlays may be
compiled statically into slapd, or when module support is enabled,
they may be dynamically loaded. Most of the overlays are only allowed
to be configured on individual databases, but some may also be
Configuration options for each overlay are documented separately in
the corresponding slapo-<overlay>(5) manual pages.
Access Logging. This overlay can record accesses to a given
backend database on another database.
Audit Logging. This overlay records changes on a given
backend database to an LDIF log file. By default it is not
chain Chaining. This overlay allows automatic referral chasing when
a referral would have been returned, either when configured by
the server or when requested by the client.
Collective Attributes. This overlay implements RFC 3671
collective attributes; these attributes share common values
over all the members of the collection as inherited from an
Constraint. This overlay enforces a regular expression
constraint on all values of specified attributes. It is used
to enforce a more rigorous syntax when the underlying
attribute syntax is too general.
dds Dynamic Directory Services. This overlay supports dynamic
objects, which have a limited life after which they expire and
are automatically deleted.
Dynamic Group. This is a demo overlay which extends the
Compare operation to detect members of a dynamic group. It
has no effect on any other operations.
Dynamic List. This overlay allows expansion of dynamic groups
MemberOf. This overlay maintains automatic reverse group
membership values, typically stored in an attribute called
pbind Proxybind. This overlay forwards simple bind requests on a
local database to a remote LDAP server.
pcache Proxycache. This overlay allows caching of LDAP search
requests in a local database. It is most often used with the
slapd-ldap(5) or slapd-meta(5) backends.
Password Policy. This overlay provides a variety of password
control mechanisms, e.g. password aging, password reuse and
duplication control, mandatory password resets, etc.
refint Referential Integrity. This overlay can be used with a
backend database such as slapd-bdb(5) to maintain the
cohesiveness of a schema which utilizes reference attributes.
Return Code. This overlay is useful to test the behavior of
clients when server-generated erroneous and/or unusual
rwm Rewrite/remap. This overlay is experimental. It performs
basic DN/data rewrite and objectClass/attributeType mapping.
sssvlv Server Side Sorting and Virtual List Views. This overlay
implements the RFC2891 server-side sorting control and virtual
list view controls, and replaces the RFC2696 paged-results
implementation to ensure it works with the sorting technique.
Syncrepl Provider. This overlay implements the provider-side
support for syncrepl replication, including persistent search
Translucent Proxy. This overlay can be used with a backend
database such as slapd-bdb(5) to create a "translucent proxy".
Content of entries retrieved from a remote LDAP server can be
partially overridden by the database.
unique Attribute Uniqueness. This overlay can be used with a backend
database such as slapd-bdb(5) to enforce the uniqueness of
some or all attributes within a subtree.
Value Sorting. This overlay can be used to enforce a specific
order for the values of an attribute when it is returned in a
This page is part of the OpenLDAP (an open source implementation of
the Lightweight Directory Access Protocol) project. Information
about the project can be found at ⟨http://www.openldap.org/⟩. If you
have a bug report for this manual page, see
⟨http://www.openldap.org/its/⟩. This page was obtained from the
project's upstream Git repository
⟨git://git.openldap.org/openldap.git⟩ on 2017-03-13. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
OpenLDAP LDVERSION RELEASEDATE SLAPD.OVERLAYS(5)