1SLAPD-BDB(5) File Formats Manual SLAPD-BDB(5)
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6 slapd-bdb, slapd-hdb - Berkeley DB backends to slapd
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9 /etc/openldap/slapd.conf
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12 The bdb backend to slapd(8) is the recommended primary backend for a
13 normal slapd database. It uses the Sleepycat Berkeley DB (BDB) package
14 to store data. It makes extensive use of indexing and caching to speed
15 data access.
16 hdb is a variant of the bdb backend that uses a hierarchical database
18 layout which supports subtree renames. It is otherwise identical to the
19 bdb behavior, and all the same configuration options apply.
20 It is noted that these options are intended to complement Berkeley DB
22 configuration options set in the environment's DB_CONFIG file. See
23 Berkeley DB documentation for details on DB_CONFIG configuration
24 options. Where there is overlap, settings in DB_CONFIG take prece‐
25 dence.
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28 These slapd.conf options apply to the bdb and hdb backend database.
29 That is, they must follow a "database bdb" or "database hdb" line and
30 come before any subsequent "backend" or "database" lines. Other data‐
31 base options are described in the slapd.conf(5) manual page.
32 cachesize <integer>
34 Specify the size in entries of the in-memory entry cache main‐
35 tained by the bdb or hdb backend database instance. The default
36 is 1000 entries.
37 cachefree <integer>
39 Specify the number of entries to free from the entry cache when
40 the cache reaches the cachesize limit. The default is 1 entry.
41 checkpoint <kbyte> <min>
43 Specify the frequency for checkpointing the database transaction
44 log. A checkpoint operation flushes the database buffers to
45 disk and writes a checkpoint record in the log. The checkpoint
46 will occur if either <kbyte> data has been written or <min> min‐
47 utes have passed since the last checkpoint. Both arguments
48 default to zero, in which case they are ignored. When the <min>
49 argument is non-zero, an internal task will run every <min> min‐
50 utes to perform the checkpoint. See the Berkeley DB reference
51 guide for more details.
52 dbconfig <Berkeley-DB-setting>
54 Specify a configuration directive to be placed in the DB_CONFIG
55 file of the database directory. The dbconfig directive is just a
56 convenience to allow all necessary configuration to be set in
57 the slapd.conf file. The options set using this directive will
58 only be written to the DB_CONFIG file if no such file existed at
59 server startup time. This allows one to set initial values with‐
60 out overwriting/destroying a DB_CONFIG file that was already
61 customized through other means. This directive may be specified
62 multiple times, as needed. For example:
63 dbconfig set_cachesize 0 1048576 0
64 dbconfig set_lg_bsize 2097152
65 dbnosync
67 Specify that on-disk database contents should not be immediately
68 synchronized with in memory changes. Enabling this option may
69 improve performance at the expense of data security. See the
70 Berkeley DB reference guide for more details.
71 directory <directory>
73 Specify the directory where the BDB files containing this data‐
74 base and associated indexes live. A separate directory must be
75 specified for each database. The default is /var/openldap-data.
76 dirtyread
78 Allow reads of modified but not yet committed data. Usually
79 transactions are isolated to prevent other operations from
80 accessing uncommitted data. This option may improve perfor‐
81 mance, but may also return inconsistent results if the data
82 comes from a transaction that is later aborted. In this case,
83 the modified data is discarded and a subsequent search will
84 return a different result.
85 idlcachesize <integer>
87 Specify the size of the in-memory index cache, in index slots.
88 The default is zero. A larger value will speed up frequent
89 searches of indexed entries. An hdb database needs a large idl‐
90 cachesize for good search performance, typically three times the
91 cachesize (entry cache size) or larger.
92 index {<attrlist>|default} [pres,eq,approx,sub,<special>]
94 Specify the indexes to maintain for the given attribute (or list
95 of attributes). Some attributes only support a subset of
96 indexes. If only an <attr> is given, the indices specified for
97 default are maintained. Note that setting a default does not
98 imply that all attributes will be indexed. Also, for best per‐
99 formance, an eq index should always be configured for the
100 objectClass attribute.
101 A number of special index parameters may be specified. The
103 index type sub can be decomposed into subinitial, subany, and
104 subfinal indices. The special type nolang may be specified to
105 disallow use of this index by language subtypes. The special
106 type nosubtypes may be specified to disallow use of this index
107 by named subtypes. Note: changing index settings in
108 slapd.conf(5) requires rebuilding indices, see slapindex(8);
109 changing index settings dynamically by LDAPModifying "cn=config"
110 automatically causes rebuilding of the indices online in a back‐
111 ground task.
112 linearindex
114 Tell slapindex to index one attribute at a time. By default, all
115 indexed attributes in an entry are processed at the same time.
116 With this option, each indexed attribute is processed individu‐
117 ally, using multiple passes through the entire database. This
118 option improves slapindex performance when the database size
119 exceeds the dbcache size. When the dbcache is large enough, this
120 option is not needed and will decrease performance. Also by
121 default, slapadd performs full indexing and so a separate
122 slapindex run is not needed. With this option, slapadd does no
123 indexing and slapindex must be used.
124 lockdetect {oldest|youngest|fewest|random|default}
126 Specify which transaction to abort when a deadlock is detected.
127 The default is random.
128 mode <integer>
130 Specify the file protection mode that newly created database
131 index files should have. The default is 0600.
132 searchstack <depth>
134 Specify the depth of the stack used for search filter evalua‐
135 tion. Search filters are evaluated on a stack to accommodate
136 nested AND / OR clauses. An individual stack is assigned to each
137 server thread. The depth of the stack determines how complex a
138 filter can be evaluated without requiring any additional memory
139 allocation. Filters that are nested deeper than the search stack
140 depth will cause a separate stack to be allocated for that par‐
141 ticular search operation. These allocations can have a major
142 negative impact on server performance, but specifying too much
143 stack will also consume a great deal of memory. Each search
144 stack uses 512K bytes per level. The default stack depth is 16,
145 thus 8MB per thread is used.
146 shm_key <integer>
148 Specify a key for a shared memory BDB environment. By default
149 the BDB environment uses memory mapped files. If a non-zero
150 value is specified, it will be used as the key to identify a
151 shared memory region that will house the environment.
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154 The bdb and hdb backends honor access control semantics as indicated in
155 slapd.access(5).
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158 /etc/openldap/slapd.conf
159 default slapd configuration file
160 DB_CONFIG
162 Berkeley DB configuration file
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165 slapd.conf(5), slapd(8), slapadd(8), slapcat(8), slapindex(8), Berkeley
166 DB documentation.
167OpenLDAP 2.3.34 2007/2/16 SLAPD-BDB(5)