Merge remote branch 'origin/mdb.master'

[openldap] / doc / man / man5 / slapd-bdb.5

diff --git a/doc/man/man5/slapd-bdb.5 b/doc/man/man5/slapd-bdb.5
index 630aecb5455f357139338d8adc96456749d83303..f64e6d3e4b311af70d03836b4884506976767c94 100644 (file)
--- a/doc/man/man5/slapd-bdb.5
+++ b/doc/man/man5/slapd-bdb.5
@@ -1,53 +1,137 @@
-.TH SLAPD-BDB 5 "30 April 2002" "OpenLDAP LDVERSION"
-.\" Copyright 1998-2002 The OpenLDAP Foundation All Rights Reserved.
+.TH SLAPD-BDB 5 "RELEASEDATE" "OpenLDAP LDVERSION"
+.\" Copyright 1998-2011 The OpenLDAP Foundation All Rights Reserved.

 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .\" $OpenLDAP$
 .SH NAME
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .\" $OpenLDAP$
 .SH NAME

-slapd-bdb \- BDB backend to slapd
+slapd\-bdb, slapd\-hdb \- Berkeley DB backends to slapd

 .SH SYNOPSIS
 .SH SYNOPSIS

-ETCDIR/slapd.conf
+.B ETCDIR/slapd.conf

 .SH DESCRIPTION
 .SH DESCRIPTION

-The BDB backend to
+The \fBbdb\fP backend to

 .BR slapd (8)
 .BR slapd (8)

-is the recommended backend for a normal slapd database.
-It uses the Sleepycat BerkelyDB package to store data.
+uses the Oracle Berkeley DB (BDB) package to store data.

 It makes extensive use of indexing and caching to speed data access.
 It makes extensive use of indexing and caching to speed data access.

+.LP
+\fBhdb\fP is the recommended primary database backend.  It is a variant of
+the \fBbdb\fP backend that uses a hierarchical database layout which
+supports subtree renames. It is both more space-efficient and more
+execution-efficient than the \fBbdb\fP backend.  It is otherwise identical
+to the \fBbdb\fP behavior, and all the same configuration options apply.
+.LP
+It is noted that these options are intended to complement
+Berkeley DB configuration options set in the environment's
+.B DB_CONFIG
+file.  See Berkeley DB documentation for details on
+.B DB_CONFIG
+configuration options.
+Where there is overlap, settings in
+.B DB_CONFIG
+take precedence.

 .SH CONFIGURATION
 These
 .B slapd.conf
 .SH CONFIGURATION
 These
 .B slapd.conf

-options apply to the BDB backend database.
-That is, they must follow a "database bdb" line and come before any
-subsequent "backend" or "database" lines.
+options apply to the \fBbdb\fP and \fBhdb\fP backend database.
+That is, they must follow a "database bdb" or "database hdb" line and
+come before any subsequent "backend" or "database" lines.

 Other database options are described in the
 .BR slapd.conf (5)
 manual page.
 .TP
 Other database options are described in the
 .BR slapd.conf (5)
 manual page.
 .TP

-.B cachesize <integer>
-Specify the size in entries of the in-memory cache maintained 
-by the BDB backend database instance.
+.BI cachesize \ <integer>
+Specify the size in entries of the in-memory entry cache maintained 
+by the \fBbdb\fP or \fBhdb\fP backend database instance.

 The default is 1000 entries.
 .TP
 The default is 1000 entries.
 .TP

-.B checkpoint <kbyte> <min>
+.BI cachefree \ <integer>
+Specify the number of entries to free from the entry cache when the
+cache reaches the \fBcachesize\fP limit.
+The default is 1 entry.
+.TP
+.BI checkpoint \ <kbyte>\ <min>

 Specify the frequency for checkpointing the database transaction log.
 A checkpoint operation flushes the database buffers to disk and writes
 a checkpoint record in the log.
 Specify the frequency for checkpointing the database transaction log.
 A checkpoint operation flushes the database buffers to disk and writes
 a checkpoint record in the log.

-The checkpoint will occur if either <kbyte> data has been written or
-<min> minutes have passed since the last checkpoint.
-Both arguments default to zero, in which case they are ignored.
+The checkpoint will occur if either \fI<kbyte>\fP data has been written or
+\fI<min>\fP minutes have passed since the last checkpoint.
+Both arguments default to zero, in which case they are ignored. When
+the \fI<min>\fP argument is non-zero, an internal task will run every 
+\fI<min>\fP minutes to perform the checkpoint.

 See the Berkeley DB reference guide for more details.
 .TP
 See the Berkeley DB reference guide for more details.
 .TP

+.B checksum
+Enable checksum validation of DB pages whenever they are read from disk.
+This setting can only be configured before any database files are created.
+.TP
+.BI cryptfile \ <file>
+Specify the pathname of a file containing an encryption key to use for
+encrypting the database. Encryption is performed using Berkeley DB's
+implementation of AES. Note that encryption can only be configured before
+any database files are created, and changing the key can only be done
+after destroying the current database and recreating it. Encryption is
+not enabled by default, and some distributions of Berkeley DB do not
+support encryption.
+.TP
+.BI cryptkey \ <key>
+Specify an encryption key to use for encrypting the database. This option
+may be used when a separate
+.I cryptfile
+is not desired. Only one of
+.B cryptkey
+or
+.B cryptfile
+may be configured.
+.TP
+.BI dbconfig \ <Berkeley-DB-setting>
+Specify a configuration directive to be placed in the
+.B DB_CONFIG
+file of the database directory. The
+.B dbconfig
+directive is just a convenience
+to allow all necessary configuration to be set in the
+.B slapd.conf
+file.
+The options set using this directive will only be written to the 
+.B DB_CONFIG
+file if no such file existed at server startup time, otherwise
+they are completely ignored. This allows one
+to set initial values without overwriting/destroying a 
+.B DB_CONFIG 
+file that was already customized through other means. 
+This directive may be specified multiple times, as needed. 
+For example:
+.RS
+.nf
+       dbconfig set_cachesize 0 1048576 0
+       dbconfig set_lg_bsize 2097152
+.fi
+.RE
+.TP

 .B dbnosync
 Specify that on-disk database contents should not be immediately
 synchronized with in memory changes.
 Enabling this option may improve performance at the expense of data
 security.
 .B dbnosync
 Specify that on-disk database contents should not be immediately
 synchronized with in memory changes.
 Enabling this option may improve performance at the expense of data
 security.

+See the Berkeley DB reference guide for more details.

 .TP
 .TP

-.B directory <directory>
+\fBdbpagesize \fR \fI<dbfile> <size>\fR
+Specify the page size to use for a particular database file, in units
+of 1024 bytes. The default for the
+.B id2entry
+file is 16, the default for all other files depends on the size of the
+underlying filesystem's block size (typically 4 or 8).
+The maximum that BerkeleyDB supports is 64. This
+setting usually should not need to be changed, but if BerkeleyDB's
+"db_stat \-d" shows a large amount of overflow pages in use in a file,
+setting a larger size may increase performance at the expense of
+data integrity. This setting only takes effect when a database is
+being newly created. See the Berkeley DB reference guide for more details.
+.TP
+.BI directory \ <directory>

 Specify the directory where the BDB files containing this database and
 associated indexes live.
 A separate directory must be specified for each database.
 The default is
 Specify the directory where the BDB files containing this database and
 associated indexes live.
 A separate directory must be specified for each database.
 The default is

-.BR LOCALSTATEDIR/openldap-data .
+.BR LOCALSTATEDIR/openldap\-data .

 .TP
 .B dirtyread
 Allow reads of modified but not yet committed data.
 .TP
 .B dirtyread
 Allow reads of modified but not yet committed data.


@@ -58,15 +142,42 @@ results if the data comes from a transaction that is later aborted.
 In this case, the modified data is discarded and a subsequent search
 will return a different result.
 .TP
 In this case, the modified data is discarded and a subsequent search
 will return a different result.
 .TP

-.B
-index {<attrlist>|default} [pres,eq,approx,sub,<special>]
+.BI dncachesize \ <integer>
+Specify the maximum number of DNs in the in-memory DN cache.
+Ideally this cache should be
+large enough to contain the DNs of every entry in the database. If
+set to a smaller value than the \fBcachesize\fP it will be silently
+increased to equal the \fBcachesize\fP. The default value is 0 which
+means unlimited, i.e. the DN cache will grow without bound.
+
+It should be noted that the \fBDN cache\fP is allowed to temporarily
+grow beyond the configured size. It does this if many entries are 
+locked when it tries to do a purge, because that means they're
+legitimately in use. Also, the \fBDN cache\fP never purges entries
+that have cached children, so depending on the shape of the DIT, it 
+could have lots of cached DNs over the defined limit.
+.TP
+.BI idlcachesize \ <integer>
+Specify the size of the in-memory index cache, in index slots. The
+default is zero. A larger value will speed up frequent searches of
+indexed entries. An \fBhdb\fP database needs a large \fBidlcachesize\fP
+for good search performance, typically three times the 
+.B cachesize
+(entry cache size)
+or larger.
+.TP
+\fBindex \fR{\fI<attrlist>\fR|\fBdefault\fR} [\fBpres\fR,\fBeq\fR,\fBapprox\fR,\fBsub\fR,\fI<special>\fR]

 Specify the indexes to maintain for the given attribute (or
 list of attributes).
 Some attributes only support a subset of indexes.
 Specify the indexes to maintain for the given attribute (or
 list of attributes).
 Some attributes only support a subset of indexes.

-If only an <attr> is given, the indices specified for \fBdefault\fR
+If only an \fI<attr>\fP is given, the indices specified for \fBdefault\fR

 are maintained.
 Note that setting a default does not imply that all attributes will be
 are maintained.
 Note that setting a default does not imply that all attributes will be

-indexed.
+indexed. Also, for best performance, an
+.B eq
+index should always be configured for the
+.B objectClass
+attribute.

 
 A number of special index parameters may be specified.
 The index type
 
 A number of special index parameters may be specified.
 The index type


@@ -82,23 +193,89 @@ may be specified to disallow use of this index by language subtypes.
 The special type
 .B nosubtypes
 may be specified to disallow use of this index by named subtypes.
 The special type
 .B nosubtypes
 may be specified to disallow use of this index by named subtypes.

-Note: changing index settings requires rebuilding indices, see
-.BR slapindex (8).
+Note: changing \fBindex\fP settings in 
+.BR slapd.conf (5)
+requires rebuilding indices, see
+.BR slapindex (8);
+changing \fBindex\fP settings
+dynamically by LDAPModifying "cn=config" automatically causes rebuilding
+of the indices online in a background task.

 .TP
 .TP

-.B lockdetect {oldest|youngest|fewest|random|default}
+.B linearindex
+Tell 
+.B slapindex 
+to index one attribute at a time. By default, all indexed
+attributes in an entry are processed at the same time. With this option,
+each indexed attribute is processed individually, using multiple passes
+through the entire database. This option improves 
+.B slapindex 
+performance
+when the database size exceeds the \fBdbcache\fP size. When the \fBdbcache\fP is
+large enough, this option is not needed and will decrease performance.
+Also by default, 
+.B slapadd 
+performs full indexing and so a separate 
+.B slapindex
+run is not needed. With this option, 
+.B slapadd 
+does no indexing and 
+.B slapindex
+must be used.
+.TP
+.BR lockdetect \ { oldest | youngest | fewest | random | default }

 Specify which transaction to abort when a deadlock is detected.
 Specify which transaction to abort when a deadlock is detected.

-The default is the same as
+The default is

 .BR random .
 .TP
 .BR random .
 .TP

-.B mode <integer>
+.BI mode \ <integer>

 Specify the file protection mode that newly created database 
 index files should have.
 The default is 0600.
 Specify the file protection mode that newly created database 
 index files should have.
 The default is 0600.

+.TP
+.BI searchstack \ <depth>
+Specify the depth of the stack used for search filter evaluation.
+Search filters are evaluated on a stack to accommodate nested AND / OR
+clauses. An individual stack is assigned to each server thread.
+The depth of the stack determines how complex a filter can be
+evaluated without requiring any additional memory allocation. Filters that
+are nested deeper than the search stack depth will cause a separate
+stack to be allocated for that particular search operation. These
+allocations can have a major negative impact on server performance,
+but specifying too much stack will also consume a great deal of memory.
+Each search stack uses 512K bytes per level. The default stack depth
+is 16, thus 8MB per thread is used.
+.TP
+.BI shm_key \ <integer>
+Specify a key for a shared memory BDB environment. By default the
+BDB environment uses memory mapped files. If a non-zero value is
+specified, it will be used as the key to identify a shared memory
+region that will house the environment.
+.SH ACCESS CONTROL
+The 
+.B bdb
+and
+.B hdb
+backends honor access control semantics as indicated in
+.BR slapd.access (5).

 .SH FILES
 .SH FILES

-ETCDIR/slapd.conf
+.TP
+.B ETCDIR/slapd.conf
+default 
+.B slapd 
+configuration file
+.TP
+.B DB_CONFIG
+Berkeley DB configuration file

 .SH SEE ALSO
 .BR slapd.conf (5),
 .SH SEE ALSO
 .BR slapd.conf (5),

+.BR slapd\-config (5),

 .BR slapd (8),
 .BR slapadd (8),
 .BR slapcat (8),
 .BR slapd (8),
 .BR slapadd (8),
 .BR slapcat (8),

-.BR slapindex (8).
+.BR slapindex (8),
+Berkeley DB documentation.
+.SH ACKNOWLEDGEMENTS
+.so ../Project
+Originally begun by Kurt Zeilenga. Caching mechanisms originally designed
+by Jong-Hyuk Choi. Completion and subsequent work, as well as
+back-hdb, by Howard Chu.