Merge remote branch 'origin/mdb.master' into OPENLDAP_REL_ENG_2_4

[openldap] / doc / guide / admin / backends.sdf

diff --git a/doc/guide/admin/backends.sdf b/doc/guide/admin/backends.sdf
index c9d403c28b237ba0dbe1c767d85a399167a8cb09..8a32cc3e52837379c364fea0ba7e4f9b1a61ab55 100644 (file)
--- a/doc/guide/admin/backends.sdf
+++ b/doc/guide/admin/backends.sdf
@@ -1,9 +1,22 @@
 # $OpenLDAP$
-# Copyright 2007-2008 The OpenLDAP Foundation, All Rights Reserved.
+# Copyright 2007-2012 The OpenLDAP Foundation, All Rights Reserved.
 # COPYING RESTRICTIONS APPLY, see COPYRIGHT.
 
 H1: Backends
 
+Backends do the actual work of storing or retrieving data in response
+to LDAP requests. Backends may be compiled statically into {{slapd}},
+or when module support is enabled, they may be dynamically loaded.
+
+If your installation uses dynamic modules, you may need to add the
+relevant {{moduleload}} directives to the examples that follow. The
+name of the module for a backend is usually of the form:
+
+>      back_<backend name>.la
+
+So for example, if you need to load the {{hdb}} backend, you would configure
+
+>      moduleload back_hdb.la
 
 H2: Berkeley DB Backends
 
@@ -126,18 +139,11 @@ configuration lines:
 >      include ./schema/core.schema
 >      
 >      database  ldif
->      directory "./ldif"
+>      directory ./ldif
 >      suffix    "dc=suretecsystems,dc=com"
 >      rootdn    "cn=LDIF,dc=suretecsystems,dc=com"
 >      rootpw    LDIF
 
-You'll notice that when compared to examples below, there is no:
-
->   moduleload  back_ldif.la
-
-directive. This is because {{back_ldif}} is always built in by default as it is
-used by {{slapd-config(5)}}, which again is built in by default.
-
 If we add the {{dcObject}} for {{dc=suretecsystems,dc=com}}, you can see how this
 is added behind the scenes on the file system:
 
@@ -181,6 +187,42 @@ H3: Further Information
 
 {{slapd-ldif}}(5)
 
+H2: MDB
+
+
+H3: Overview
+
+The {{mdb}} backend to {{slapd}}(8) is the upcoming primary backend for a
+normal {{slapd}} database.  It uses OpenLDAP's own Memory-Mapped Database ({{TERM:MDB}})
+library to store data and is intended to replace the Berkeley DB backends.
+
+It supports indexing like the BDB backends, but it uses no caching and requires
+no tuning to deliver maximum search performance.  Like {{hdb}}, it is also
+fully hierarchical and supports subtree renames in constant time.
+
+H3: back-mdb Configuration
+
+Unlike the BDB backends, the MDB backend can be instantiated with very few
+configuration lines:
+
+>      include ./schema/core.schema
+>
+>      database  mdb
+>      directory ./mdb
+>      suffix    "dc=suretecsystems,dc=com"
+>      rootdn    "cn=mdb,dc=suretecsystems,dc=com"
+>      rootpw    mdb
+>      maxsize   1073741824
+
+In addition to the usual parameters that a minimal configuration requires, the MDB
+backend requires a maximum size to be set. This should be the largest that
+the database is ever anticipated to grow (in bytes). The filesystem must also
+provide enough free space to accommodate this size.
+
+H3: Further Information
+
+{{slapd-mdb}}(5)
+
 H2: Metadirectory
 
 
@@ -237,9 +279,6 @@ You can however set a {{rootdn}} and {{rootpw}}. The following is all that is
 needed to instantiate a monitor backend:
 
 >      include ./schema/core.schema
->
->      modulepath  /usr/local/libexec/openldap
->      moduleload  back_monitor.la
 >      
 >      database monitor
 >      rootdn "cn=monitoring,cn=Monitor"
@@ -308,16 +347,10 @@ H3: back-null Configuration
 This has to be one of the shortest configurations you'll ever do. In order to 
 test this, your {{F: slapd.conf}} file would look like:
 
->      modulepath  /usr/local/libexec/openldap
->      moduleload  back_null.la
-
 >      database null
 >      suffix "cn=Nothing"
 >      bind on
 
-The first two directives are only applicable if you've enabled module support and
-haven't "built-in" {{slapd-null(5)}} support (why would you?).
-
 {{bind on}} means:
 
 {{"Allow binds as any DN in this backend's suffix, with any password. The default is "off"."}}
@@ -362,9 +395,6 @@ example:
 
 >      include ./schema/core.schema
 >      
->      modulepath  /usr/local/libexec/openldap
->      moduleload  back_passwd.la
->      
 >      database passwd
 >      suffix "cn=passwd"