3.4.1.4 nsslapd-dbcachesize

This performance tuning-related attribute specifies the database index cache size, and is one of the most important values for controlling how much physical RAM the directory server uses.

This is not the entry cache. This is the amount of memory the Berkeley database backend will use to cache the indexes (the .db4 files) and other files. This value is passed to the Berkeley DB API function set_cachesize. If automatic cache resizing is activated, this attribute is overridden when the server replaces these values with its own guessed values at a later stage of the server startup. For more technical information on this attribute, see the cache size section of the Berkeley DB reference guide.

Attempting to set a value that is not a number or is too big for a 32-bit signed integer returns an LDAP_UNWILLING_TO_PERFORM error message with additional error information explaining the problem.

The server has to be restarted for changes to this attribute to go into effect.

Parameter

Description

Entry DN

cn=config, cn=ldbm database, cn=plugins, cn=config

 

 

Valid Range

500 kilobytes to 4 gigabytes for 32-bit platforms and 500 kilobytes to 2^64-1 for 64-bit

 

platforms

 

 

Default Value

10000000 bytes

 

 

Syntax

Integer

 

 

Example

nsslapd-dbcachesize: 10,000,000

 

 

3.4.1.5 nsslapd-db-checkpoint-interval

This sets the amount of time in seconds after which the Directory Server sends a checkpoint entry to the database transaction log. The database transaction log contains a sequential listing of all recent database operations and is used for database recovery only. A checkpoint entry indicates which database operations have been physically written to the directory database. The checkpoint entries are used to determine where in the database transaction log to begin recovery after a system failure. The nsslapd-db-checkpoint-intervalattribute is absent from dse.ldif. To change the checkpoint interval, add the attribute to dse.ldif. This attribute can be dynamically modified using the ldapmodify command. For further information on modifying this attribute, see the "Tuning Directory Server Performance" chapter in the HP-UX Directory Server administrator guide.

This attribute is provided only for system modification/diagnostics and should be changed only with the guidance of HP technical support or HP professional services. Inconsistent settings of this attribute and other configuration attributes may cause the Directory Server to be unstable.

For more information on database transaction logging, refer to the "Monitoring Server and Database Activity" chapter in the HP-UX Directory Server administrator guide.

Parameter

Description

Entry DN

cn=config, cn=ldbm database, cn=plugins, cn=config

 

 

Valid Range

10 to 300 seconds

 

 

Default Value

60

 

 

Syntax

Integer

 

 

Example

nsslapd-db-checkpoint-interval: 120

 

 

134 Plug-in implemented server functionality reference