> olcDbDirectory: /usr/local/var/openldap-data
-H4: Sample Entry
+H4: olcDbCachesize: <integer>
->dn: olcDatabase=bdb,cn=config
->objectClass: olcDatabaseConfig
->objectClass: olcBdbConfig
->olcDatabase: bdb
->olcSuffix: "dc=example,dc=com"
->olcDbDirectory: /usr/local/var/openldap-data
+This directive specifies the size in entries of the in-memory
+cache maintained by the BDB backend database instance.
-H3: LDBM Database Directives
+\Default:
-Directives in this category only apply to a {{TERM:LDBM}} database.
-That is, they must follow a "database ldbm" line and come before
-any subsequent "backend" or "database" line. For a complete reference
-of LDBM configuration directives, see {{slapd-ldbm}}(5).
+> olcDbCachesize: 1000
-H4: cachesize <integer>
-This directive specifies the size in entries of the in-memory
-cache maintained by the LDBM backend database instance.
+H4: olcDbCheckpoint: <kbyte> <min>
-\Default:
+This directive specifies how often to checkpoint the BDB 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 checkpont. Both arguments default
+to zero, in which case they are ignored. When the <min> argument is
+non-zero, an internal task will run every <min> minutes to perform the
+checkpoint. See the Berkeley DB reference guide for more details.
-> cachesize 1000
+\Example:
+> olcDbCheckpoint: 1024 10
-H4: dbcachesize <integer>
-This directive specifies the size in bytes of the in-memory cache
-associated with each open index file. If not supported by the
-underlying database method, this directive is ignored without
-comment. Increasing this number uses more memory but can
-cause a dramatic performance increase, especially during
-modifies or when building indices.
+H4: olcDbConfig: <DB_CONFIG setting>
-\Default:
+This attribute specifies a configuration directive to be placed in the
+{{EX:DB_CONFIG}} file of the database directory. At server startup time, if
+no such file exists yet, the {{EX:DB_CONFIG}} file will be created and the
+settings in this attribute will be written to it. If the file exists,
+its contents will be read and displayed in this attribute. The attribute
+is multi-valued, to accomodate multiple configuration directives. No default
+is provided, but it is essential to use proper settings here to get the
+best server performance.
-> dbcachesize 100000
+\Example:
+> olcDbConfig: set_cachesize 0 10485760 0
+> olcDbConfig: set_lg_bsize 2097512
+> olcDbConfig: set_lg_dir /var/tmp/bdb-log
+> olcDbConfig: set_flags DB_LOG_AUTOREMOVE
-H4: dbnolocking
+In this example, the BDB cache is set to 10MB, the BDB transaction log
+buffer size is set to 2MB, and the transaction log files are to be stored
+in the /var/tmp/bdb-log directory. Also a flag is set to tell BDB to
+delete transaction log files as soon as their contents have been
+checkpointed and they are no longer needed. Without this setting the
+transaction log files will continue to accumulate until some other
+cleanup procedure removes them. See the SleepyCat documentation for the
+{{EX:db_archive}} command for details.
-This option, if present, disables database locking.
-Enabling this option may improve performance at the expense
-of data security.
+Ideally the BDB cache must be
+at least as large as the working set of the database, the log buffer size
+should be large enough to accomodate most transactions without overflowing,
+and the log directory must be on a separate physical disk from the main
+database files. And both the database directory and the log directory
+should be separate from disks used for regular system activities such as
+the root, boot, or swap filesystems. See the FAQ-o-Matic and the SleepyCat
+documentation for more details.
-H4: dbnosync
+H4: olcDbNosync: <TRUE|FALSE>
This option causes on-disk database contents to not be immediately
-synchronized with in memory changes upon change. Enabling this option
-may improve performance at the expense of data integrity.
+synchronized with in memory changes upon change. Setting this option
+to TRUE may improve performance at the expense of data integrity. This
+directive has the same effect as using
+> olcDbConfig: set_flags DB_TXN_NOSYNC
-H4: directory <directory>
+H4: olcDbIDLcacheSize: <integer>
-This directive specifies the directory where the LDBM files
-containing the database and associated indices live.
+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. The optimal size will depend on the data and search
+characteristics of the database, but using a number three times
+the entry cache size is a good starting point.
-\Default:
+\Example:
-> directory /usr/local/var/openldap-data
+> olcDbIDLcacheSize: 3000
-H4:
index {<attrlist> | default} [pres,eq,approx,sub,none]
+H4:
olcDbIndex: {<attrlist> | default} [pres,eq,approx,sub,none]
This directive specifies the indices to maintain for the given
attribute. If only an {{EX:<attrlist>}} is given, the default
\Example:
-> index default pres,eq
-> index uid
-> index cn,sn pres,eq,sub
-> index objectClass eq
+> olcDbIndex: default pres,eq
+> olcDbIndex: uid
+> olcDbIndex: cn,sn pres,eq,sub
+> olcDbIndex: objectClass eq
The first line sets the default set of indices to maintain to
present and equality. The second line causes the default (pres,eq)
By default, no indices are maintained. It is generally advised
that minimally an equality index upon objectClass be maintained.
-> index objectClass eq
+> olcDbindex: objectClass eq
+
+If this setting is changed while slapd is running, an internal task
+will be run to generate the changed index data. All server operations
+can continue as normal while the indexer does its work. If slapd is
+stopped before the index task completes, indexing will have to be
+manually completed using the slapindex tool.
+
+H4: olcDbLinearIndex: <TRUE|FALSE>
+If this setting is {{EX:TRUE}} slapindex will index one attribute
+at a time. The default settings is {{EX:FALSE}} in which case all
+indexed attributes of an entry are processed at the same time. When
+enabled, each indexed attribute is processed individually, using
+multiple passes through the entire database. This option improves
+slapindex performance when the database size exceeds the BDB cache
+size. When the BDB cache is large enough, this option is not needed
+and will decrease performance. Also by default, slapadd performs
+full indexing and so a separate slapindex run is not needed. With
+this option, slapadd does no indexing and slapindex must be used.
-H4: mode <integer>
+
+H4: olcDbMode: <integer>
This directive specifies the file protection mode that newly
created database index files should have.
\Default:
-> mode 0600
+> olcDbMode: 0600
+
+H4: olcDbSearchStack: <integer>
+
+Specify the depth of the stack used for search filter evaluation.
+Search filters are evaluated on a stack to accomodate nested {{EX:AND}} /
+{{EX:OR}} clauses. An individual stack is allocated for 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 separate 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
+uses 512K bytes per level on a 32-bit machine, or 1024K bytes per level
+on a 64-bit machine. The default stack depth is 16, thus 8MB or 16MB
+per thread is used on 32 and 64 bit machines, respectively. Also the
+512KB size of a single stack slot is set by a compile-time constant which
+may be changed if needed; the code must be recompiled for the change
+to take effect.
+
+\Default:
+
+> olcDbSearchStack: 16
+
+
+H4: olcDbShmKey: <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.
+
+\Example:
+
+> olcDbShmKey: 42
+
+
+H4: Sample Entry
+
+>dn: olcDatabase=bdb,cn=config
+>objectClass: olcDatabaseConfig
+>objectClass: olcBdbConfig
+>olcDatabase: bdb
+>olcSuffix: "dc=example,dc=com"
+>olcDbDirectory: /usr/local/var/openldap-data
+>olcDbCacheSize: 1000
+>olcDbCheckpoint: 1024 10
+>olcDbConfig: set_cachesize 0 10485760 0
+>olcDbConfig: set_lg_bsize 2097152
+>olcDbConfig: set_lg_dir /var/tmp/bdb-log
+>olcDbConfig: set_flags DB_LOG_AUTOREMOVE
+>olcDbIDLcacheSize: 3000
+>olcDbIndex: objectClass eq
+
+
+Note: the remainder of this chapter has not yet been updated to reflect
+the new cn=config mechanisms.
H2: Access Control
projects / openldap / commitdiff