IBM Security Directory Server, Version 6.3.1

Tuning DB2 and LDAP caches

You can tune the DB2 database that is configured with a directory server instance to reduce the search and update time.

IBM® Security Directory Server uses DB2® as the data store; and Structured Query Language (SQL) as the query retrieval mechanism. While the LDAP server caches LDAP queries, results, and authentication information; DB2 caches tables, indexes, and statements.

Many DB2 configuration parameters affect either the memory (buffer pools) or disk resources. Since disk access is usually much slower than memory access, the key database performance tuning objective is to decrease the amount of disk activity. In DB2, version 9.1 and later, you can use Self Tuning Memory Manager (STMM) instead of manually tuning several DB2 parameters. When you use the STMM, DB2 assigns the correct values to memory consumers based on the usage of the system and available resources. You can use the DB2 STMM by setting the values of DB2 buffer pool to AUTOMATIC.

When you tune DB2, you must consider the following options:

Tuning DB2 buffer pool
Tuning DB2 and LDAP caches by using the idsperftune tool
Database maintenance by using the idsdbmaint tool. You can use the tool for DB2 index organization, DB2 row compression, and table space conversion.
Database maintenance by using the idsrunstats tool.
Optimization and organization (reorgchk and reorg)
Other DB2 configuration parameters
Backup and restore the database
Data row compression

For more information about DB2 commands, see the IBM DB2 documentation website at http://pic.dhe.ibm.com/infocenter/db2luw/v9r7/index.jsp.

Attention: Users that are listed as database administrators can run the DB2 commands. When you run the DB2 commands, you must user a user ID that in a member of the dbsysadm group (UNIX operating systems) or a member of the Administrator group (Windows operating systems.) The DB2 instance owner and root are members of the dbsysadm group.

If you have any issues when you run the DB2 commands, check to ensure that the DB2 environment variables are set by running db2profile. If not, the db2 get and db2 update commands might not work. The script file db2profile is in the sqllib subdirectory of the instance owner home directory. To modify the file, follow the comments inside the file to set your instance name, user paths, and default database name (the default path is /home/ldapdb2/sqllib/db2profile.) It is assumed that the user is logged in as ibm-slapdDbUserId. If logged in as the root user on a UNIX operating system, you can switch the user context to the instance owner.

su - instance_owner

where, instance_owner is the defined owner of the LDAP database.

To log on as the database administrator on a Windows 2000 operating system, run the following command:

runas /user:instance_owner db2cmd

where, instance_owner is the defined owner of the LDAP database.

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