From: Gavin Henry Date: Thu, 2 Aug 2007 21:48:35 +0000 (+0000) Subject: Merging of description sections of slapd-*. Wille expand/change later. X-Git-Tag: OPENLDAP_REL_ENG_2_4_MP~281 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=35b27857585feeef378420dd0e5f1075d19f27dc;p=openldap Merging of description sections of slapd-*. Wille expand/change later. --- diff --git a/doc/guide/admin/backends.sdf b/doc/guide/admin/backends.sdf index fc02d26aa2..cd76d8c768 100644 --- a/doc/guide/admin/backends.sdf +++ b/doc/guide/admin/backends.sdf @@ -10,92 +10,256 @@ H2: Berkley DB Backends H3: Overview +The {{bdb}} backend to {{slapd}}(8) is the recommended primary backend for a +normal {{slapd}} database. It uses the Oracle Berkeley DB ({{TERM:BDB}}) +package to store data. It makes extensive use of indexing and caching +(see {{SECT:Tuning}}) to speed data access. + +{{hdb}} is a variant of the {{bdb}} backend that uses a hierarchical database +layout which supports subtree renames. It is otherwise identical to the {{bdb}} + behavior, and all the same configuration options apply. + +Note: An {{hdb}} database needs a large {{idlcachesize}} for good search performance, +typically three times the {{cachesize}} (entry cache size) or larger. H3: back-bdb/back-hdb Configuration +MORE LATER H3: Further Information +{{slapd-bdb}}(5) H2: LDAP H3: Overview +The LDAP backend to {{slapd}}(8) is not an actual database; instead it acts +as a proxy to forward incoming requests to another LDAP server. While +processing requests it will also chase referrals, so that referrals are fully +processed instead of being returned to the {{slapd}} client. + +Sessions that explicitly {{Bind}} to the {{back-ldap}} database always create +their own private connection to the remote LDAP server. Anonymous sessions +will share a single anonymous connection to the remote server. For sessions +bound through other mechanisms, all sessions with the same DN will share the +same connection. This connection pooling strategy can enhance the proxy’s +efficiency by reducing the overhead of repeatedly making/breaking multiple +connections. + +The ldap database can also act as an information service, i.e. the identity +of locally authenticated clients is asserted to the remote server, possibly +in some modified form. For this purpose, the proxy binds to the remote server +with some administrative identity, and, if required, authorizes the asserted +identity. H3: back-ldap Configuration +LATER H3: Further Information +{{slapd-ldap}}(5) H2: LDIF H3: Overview +The LDIF backend to {{slapd}}(8) is a basic storage backend that stores +entries in text files in LDIF format, and exploits the filesystem to create +the tree structure of the database. It is intended as a cheap, low performance +easy to use backend, and it is exploited by higher-level internal structures +to provide a permanent storage. + +When using Dynamic configuration over LDAP via {{cn=config}}, this is where all +configuration is stored if {{slapd}}(8) if started with {{-F}}. See {{slapd-config.5}](5) +for more information H3: back-ldif Configuration +LATER H3: Further Information +{{slapd-ldif}}(5) H2: Metadirectory H3: Overview +The meta backend to {{slapd}}(8) performs basic LDAP proxying with respect +to a set of remote LDAP servers, called "targets". The information contained +in these servers can be presented as belonging to a single Directory Information +Tree ({{TERM:DIT}}). + +A basic knowledge of the functionality of the {{slapd-ldap}}(5) backend is +recommended. This backend has been designed as an enhancement of the ldap +backend. The two backends share many features (actually they also share portions + of code). While the ldap backend is intended to proxy operations directed + to a single server, the meta backend is mainly intended for proxying of + multiple servers and possibly naming context masquerading. + +These features, although useful in many scenarios, may result in excessive +overhead for some applications, so its use should be carefully considered. + H3: back-meta Configuration +LATER H3: Further Information +{{slapd-meta}}(5) H2: Monitor H3: Overview +The monitor backend to {{slapd}}(8) is not an actual database; if enabled, +it is automatically generated and dynamically maintained by slapd with +information about the running status of the daemon. + +To inspect all monitor information, issue a subtree search with base {{cn=Monitor}}, +requesting that attributes "+" and "*" are returned. The monitor backend produces +mostly operational attributes, and LDAP only returns operational attributes +that are explicitly requested. Requesting attribute "+" is an extension which +requests all operational attributes. + +See the {{SECT:Monitoring}} section. H3: back-monitor Configuration +LATER H3: Further Information +{{slapd-monitor}}(5) -H2: Relay +H2: Null H3: Overview +The Null backend to {{slapd}}(8) is surely the most useful part of slapd: -H3: back-relay Configuration +- Searches return success but no entries. +- Compares return compareFalse. +- Updates return success (unless readonly is on) but do nothing. +- Binds other than as the rootdn fail unless the database option "bind on" is given. +- The slapadd(8) and slapcat(8) tools are equally exciting. + +Inspired by the {{F:/dev/null}} device. +H3: back-null Configuration + +LATER H3: Further Information +{{slapd-null}}(5) -H2: Perl/Shell +H2: Passwd + + +H3: Overview + +The PASSWD backend to {{slapd}}(8) serves up the user account information +listed in the system {{passwd}}(5) file. + +This backend is provided for demonstration purposes only. The DN of each entry +is "uid=,". + +H3: back-passwd Configuration + +LATER + +H3: Further Information +{{slapd-passwd}}(5) + +H2: Perl/Shell H3: Overview +The Perl backend to {{slapd}}(8) works by embedding a {{perl}}(1) interpreter +into {{slapd}}(8). Any perl database section of the configuration file +{{slapd.conf}}(5) must then specify what Perl module to use. Slapd then creates +a new Perl object that handles all the requests for that particular instance of the backend. + +The Shell backend to {{slapd}}(8) executes external programs to implement +operations, and is designed to make it easy to tie an existing database to the +slapd front-end. This backend is is primarily intended to be used in prototypes. H3: back-perl/back-shell Configuration +LATER + +H3: Further Information + +{{slapd-shell}}(5) and {{slapd-perl}}(5) + +H2: Relay + + +H3: Overview + +The primary purpose of this {{slapd}}(8) backend is to map a naming context +defined in a database running in the same {{slapd}}(8) instance into a +virtual naming context, with attributeType and objectClass manipulation, if +required. It requires the rwm overlay. + +This backend and the above mentioned overlay are experimental. + +H3: back-relay Configuration + +LATER H3: Further Information +{{slapd-relay}}(5) H2: SQL H3: Overview +The primary purpose of this {{slapd}}(8) backend is to PRESENT information +stored in some RDBMS as an LDAP subtree without any programming (some SQL and +maybe stored procedures can’t be considered programming, anyway ;). + +That is, for example, when you (some ISP) have account information you use in +an RDBMS, and want to use modern solutions that expect such information in LDAP +(to authenticate users, make email lookups etc.). Or you want to synchronize or +distribute information between different sites/applications that use RDBMSes +and/or LDAP. Or whatever else... + +It is NOT designed as a general-purpose backend that uses RDBMS instead of +BerkeleyDB (as the standard BDB backend does), though it can be used as such with +several limitations. You can take a look at {{URL:http://www.openldap.org/faq/index.cgi?file=378}} + (OpenLDAP FAQ-O-Matic/General LDAP FAQ/Directories vs. conventional databases) + to find out more on this point. + +The idea is to use some meta-information to translate LDAP queries to SQL queries, +leaving relational schema untouched, so that old applications can continue using +it without any modifications. This allows SQL and LDAP applications to interoperate +without replication, and exchange data as needed. + +The SQL backend is designed to be tunable to virtually any relational schema without +having to change source (through that meta-information mentioned). Also, it uses +ODBC to connect to RDBMSes, and is highly configurable for SQL dialects RDBMSes +may use, so it may be used for integration and distribution of data on different +RDBMSes, OSes, hosts etc., in other words, in highly heterogeneous environment. + +This backend is experimental. H3: back-sql Configuration +LATER H3: Further Information + +{{slapd-sql}}(5)