cn=config and DB_CONFIG

[DT Piotr Wadas]

Hello,
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Regards,
DT

[Howard Chu]

Post by DT Piotr Wadas
Hello,
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Every version since 2.3.

[Hallvard B Furuseth]

Post by DT Piotr Wadas
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Yes. See the admin guide and the slapd-bdb(8) manpage, keyword
dbconfig. The cn=config attribute is called olcDbConfig. Note that
"The options set using this directive will only be written to the
DB_CONFIG file if no such file existed at server startup time"
Come to think of it, I don't know what happens if you modify an existing
database's DB_CONFIG; I've only used it with empty database directories.

[Quanah Gibson-Mount]

--On Wednesday, May 19, 2010 3:56 PM +0200 Hallvard B Furuseth

Post by Hallvard B Furuseth

Post by DT Piotr Wadas
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Yes. See the admin guide and the slapd-bdb(8) manpage, keyword
dbconfig. The cn=config attribute is called olcDbConfig. Note that
"The options set using this directive will only be written to the
DB_CONFIG file if no such file existed at server startup time"
Come to think of it, I don't know what happens if you modify an existing
database's DB_CONFIG; I've only used it with empty database directories.

It will pull in the changes the next time slapd is started.

--Quanah

--

Quanah Gibson-Mount
Principal Software Engineer
Zimbra, Inc
--------------------
Zimbra :: the leader in open source messaging and collaboration

[Howard Chu]

Post by Hallvard B Furuseth

Post by DT Piotr Wadas
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Yes. See the admin guide and the slapd-bdb(8) manpage, keyword
dbconfig. The cn=config attribute is called olcDbConfig. Note that
"The options set using this directive will only be written to the
DB_CONFIG file if no such file existed at server startup time"
Come to think of it, I don't know what happens if you modify an existing
database's DB_CONFIG; I've only used it with empty database directories.

If you ldapmodify via cn=config the DB environment will be closed and
re-opened to make the new settings take effect.

[Daniel]

Post by DT Piotr Wadas
Is it possible with openldap, any version, to tune DB_CONFIG attributes
for selected context via cn=config ?

Although I don't know in detail if and when these kind of cn=config
settings will take effect (especially for changes), it seems to be
supported:

Have a look at admin guide 2.4 and olcDBConfig attribute:
http://www.openldap.org/doc/admin24/slapdconf2.html#BDB%20and%20HDB%20Database%20Directives


BTW: Could someone confirm, that a slaptest -f -F conversion does not
effect (aka ignores) slapd's bdb DB_CONFIG convenience settings like for
example:

dbconfig set_cachesize 0 500000000 4
dbconfig set_lg_dir /extra/harddrive4performace
dbconfig set_lg_regionmax 5000000
dbconfig set_lg_bsize 5000000
dbconfig set_lg_max 25000000
dbconfig set_flags DB_LOG_AUTOREMOVE


In my case the above settings are contained in a "database hdb" section
and although slaptest -f succeeds after running slaptest -f ... -F ...
slapd.d's ldifs do not contain any olcDBConfig attribute.

Thanks!

Cheers
Daniel