6.2. Adjusting the database index cache size
Red Hat recommends using the built-in cache auto-sizing feature for optimized performance. Only change this value if you need to purposely deviate from the auto-tuned values.
The nsslapd-dbcachesize attribute controls the amount of memory the database indexes use. This cache size has less of an impact on Directory Server performance than the entry cache size does, but if there is available RAM after the entry cache size is set, Red Hat recommends increasing the amount of memory allocated to the database cache.
The database cache is limited to 1.5 GB RAM because higher values do not improve performance.
| Default value |
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| Valid range |
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| Entry DN location |
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Conditions préalables
- Le mot de passe du gestionnaire de répertoire LDAP
Procédure
Disable automatic cache tuning, and set the database cache size. This example sets the database cache to 256 megabytes.
[root@server ~]# dsconf -D "cn=Directory Manager" ldap://server.example.com backend config set --cache-autosize=0 --dbcachesize=268435456Restart the Directory Server.
[root@server ~]# systemctl restart dirsrv.target-
Monitor the IdM directory server’s performance. If it does not change in a desirable way, repeat this procedure and adjust
dbcachesizeto a different value, or re-enable cache auto-sizing.
Verification steps
Display the value of the
nsslapd-dbcachesizeattribute and verify it has been set to your desired value.[root@server ~]# ldapsearch -D "cn=directory manager" -w DirectoryManagerPassword -b "cn=config,cn=ldbm database,cn=plugins,cn=config" | grep nsslapd-dbcachesize nsslapd-dbcachesize: 2147483648
Ressources supplémentaires
- nsslapd-dbcachesize in Directory Server 11 documentation
- Re-enabling entry and database cache auto-sizing.
