SLAPD.BACKENDS(5)	      File Formats Manual	     SLAPD.BACKENDS(5)



NAME
       slapd.backends - backends for slapd, the stand-alone LDAP daemon

DESCRIPTION
       The slapd(8) daemon can use a variety of different backends for serving
       LDAP requests.  Backends may be compiled statically into slapd, or when
       module  support	is  enabled,  they may be dynamically loaded. Multiple
       instances of a backend can be configured, to serve  separate  databases
       from the same slapd server.


       Configuration options for each backend are documented separately in the
       corresponding slapd-<backend>(5) manual pages.

       bdb    This was the recommended primary backend through	OpenLDAP  2.3,
	      but  it  has since been superseded by the hdb backend.  It takes
	      care to configure it properly.  It uses the transactional	 data-
	      base  interface of the Oracle Berkeley DB (BDB) package to store
	      data.

       config This backend is used to manage the  configuration	 of  slapd  at
	      run-time.	  Unlike other backends, only a single instance of the
	      config backend may be defined. It also instantiates itself auto-
	      matically,  so  it  is  always  present  even  if not explicitly
	      defined in the slapd.conf(5) file.

       dnssrv This backend is experimental.  It serves up referrals based upon
	      SRV resource records held in the Domain Name System.

       hdb    This is the recommended primary backend for a normal slapd data-
	      base.  hdb is a variant of the bdb backend that uses  a  hierar-
	      chical database layout.  This layout stores entry DNs more effi-
	      ciently than the bdb backend, using  less	 space	and  requiring
	      less  work to create, delete, and rename entries. It is also one
	      of the few backends to support subtree renames.

       ldap   This backend acts as a proxy to  forward	incoming  requests  to
	      another LDAP server.

       ldif   This database uses the filesystem to build the tree structure of
	      the database, using plain ascii files to store data.  Its	 usage
	      should be limited to very simple databases, where performance is
	      not a requirement. This backend also supports subtree renames.

       mdb    This will soon be the recommended primary	 backend,  superseding
	      hdb.   This  backend uses OpenLDAP's own MDB transactional data-
	      base library. It is extremely compact and	 extremely  efficient,
	      delivering much higher performance than the Berkeley DB backends
	      while using significantly less memory.   Also,  unlike  Berkeley
	      DB,  MDB is crash proof, and requires no special tuning or main-
	      tenance.	This backend also supports subtree renames.

       meta   This backend performs basic LDAP proxying with respect to a  set
	      of  remote  LDAP servers. It is an enhancement of the ldap back-
	      end.

       monitor
	      This backend provides information about the  running  status  of
	      the  slapd daemon. Only a single instance of the monitor backend
	      may be defined.

       ndb    This backend is experimental.  It uses the  transactional	 data-
	      base  interface of the MySQL Cluster Engine (NDB) to store data.
	      Note that Oracle, which now owns MySQL,  has  withdrawn  support
	      for  NDB	and  this backend is unlikely to be developed any fur-
	      ther.

       null   Operations in this backend succeed but do nothing.

       passwd This backend is provided for demonstration  purposes  only.   It
	      serves  up  user	account	 information from the system passwd(5)
	      file.

       perl   This backend embeds a perl(1) interpreter into slapd.   It  runs
	      Perl subroutines to implement LDAP operations.

       relay  This  backend  is experimental.  It redirects LDAP operations to
	      another database in the same server, based on the naming context
	      of   the	request.   Its	use  requires  the  rwm	 overlay  (see
	      slapo-rwm(5) for details) to rewrite the naming context  of  the
	      request.	It is primarily intended to implement virtual views on
	      databases that actually store data.

       shell  This backend executes external programs to implement LDAP opera-
	      tions.  It is primarily intended to be used in prototypes.

       sql    This backend is experimental.  It services LDAP requests from an
	      SQL database.

FILES
       /etc/openldap/slapd.conf
	      default slapd configuration file

       /etc/openldap/slapd.d
	      default slapd configuration directory

SEE ALSO
       ldap(3), slapd-bdb(5), slapd-config(5), slapd-dnssrv(5),	 slapd-hdb(5),
       slapd-ldap(5),  slapd-ldif(5), slapd-mdb(5), slapd-meta(5), slapd-moni-
       tor(5), slapd-ndb(5),  slapd-null(5),  slapd-passwd(5),	slapd-perl(5),
       slapd-relay(5),	   slapd-shell(5),     slapd-sql(5),	slapd.conf(5),
       slapd.overlays(5),   slapd(8).	 "OpenLDAP   Administrator's	Guide"
       (http://www.OpenLDAP.org/doc/admin/)

ACKNOWLEDGEMENTS
       OpenLDAP	 Software  is developed and maintained by The OpenLDAP Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from  Univer-
       sity of Michigan LDAP 3.3 Release.



OpenLDAP 2.4.40			  2014/09/20		     SLAPD.BACKENDS(5)