/usr/man2/cat.5/slapd-bdb.5.Z
NAME
slapd-bdb, slapd-hdb - BDB backends to slapd
SYNOPSIS
/etc/openldap/slapd.conf
DESCRIPTION
The BDB backend to slapd(8) is the recommended backend for a normal
slapd database. However, it takes more care than with the LDBM backend
to configure it properly. It uses the Sleepycat Berkeley DB (BDB)
package to store data. It makes extensive use of indexing and caching
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.
It is noted that these options are intended to complement Berkeley DB
configuration options set in the environment's DB_CONFIG file. See
Berkeley DB documentation for details on DB_CONFIG configuration
options. Where there is overlap, settings in DB_CONFIG take prece-
dence.
CONFIGURATION
These slapd.conf options apply to the BDB 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 slapd.conf(5) manual page.
cachesize <integer>
Specify the size in entries of the in-memory entry cache main-
tained by the BDB backend database instance. The default is
1000 entries.
checkpoint <kbyte> <min>
Specify the frequency for checkpointing the database transaction
log upon updating of the database. A checkpoint flushes the
database buffers to disk and writes a checkpoint record in the
log. Upon a database update, a 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. Note: checkpointing by this directive
occurs only upon execution of a database update. If one desires
checkpointing to occur otherwise, db_checkpoint(1) or some other
external process should be used to cause a database checkpoint
to be taken. See the Berkeley DB reference guide for more
details.
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.
directory <directory>
Specify the directory where the BDB files containing this data-
base and associated indexes live. A separate directory must be
specified for each database. The default is /usr/lib/openl-
dap/openldap-data.
dirtyread
Allow reads of modified but not yet committed data. Usually
transactions are isolated to prevent other operations from
accessing uncommitted data. This option may improve perfor-
mance, but may also return inconsistent 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.
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 hdb database needs a large idl-
cachesize for good search performance, typically three times the
entry cache size or larger.
index {<attrlist>|default} [pres,eq,approx,sub,<special>]
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
default are maintained. Note that setting a default does not
imply that all attributes will be indexed. Also, for best per-
formance, an eq index should always be configured for the
objectClass attribute.
A number of special index parameters may be specified. The
index type sub can be decomposed into subinitial, subany, and
subfinal indices. The special type nolang may be specified to
disallow use of this index by language subtypes. The special
type nosubtypes may be specified to disallow use of this index
by named subtypes. Note: changing index settings requires
rebuilding indices, see slapindex(8).
lockdetect {oldest|youngest|fewest|random|default}
Specify which transaction to abort when a deadlock is detected.
The default is the same as random.
mode <integer>
Specify the file protection mode that newly created database
index files should have. The default is 0600.
searchstack <depth>
Specify the depth of the stack used for search filter evalua-
tion. 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 par-
ticular 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.
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.
sessionlog <sid> <limit>
Specify a session log store for the syncrepl replication
provider server. The session log store contains information on
the entries that have been scoped out of the provider replica-
tion content identified by <sid>. The number of entries in the
session log store is limited by <limit>. Excessive entries are
removed from the store in the FIFO order. Both <sid> and
<limit> are non-negative integers. <sid> has no more than three
decimal digits. Refer to the "OpenLDAP Administrator's Guide"
for detailed information on setting up a replicated slapd direc-
tory service using the syncrepl replication engine and the ses-
sion log store.
FILES
/etc/openldap/slapd.conf
default slapd configuration file
DB_CONFIG
Berkeley DB configuration file
SEE ALSO
slapd.conf(5), slapd(8), slapadd(8), slapcat(8), slapindex(8), Berkeley
DB documentation.
OpenLDAP 2.2.30 2005/11/18 SLAPD-BDB(5)
See also slapd-hdb(5)
Man(1) output converted with
man2html