HP-UX Directory Server Administrator Guide HP-UX Directory Server Version 8.1 (5900-3098, May 2013)

1. Stop the Directory Server.
/opt/dirsrv/slapd-instance_name/stop-slapd
2. In the dse.ldif file, locate the entry for the nsslapd-db-logdirectory attribute,
cn=config,cn=ldbm database,cn=plugins,cn=config. Provide the full path to the
log directory in the attribute.
3. Start Directory Server.
/opt/dirsrv/slapd-instance_name/start-slapd
16.2.4 Changing the database checkpoint interval
At regular intervals, the Directory Server writes operations logged in the transaction log to the disk
and logs a checkpoint entry in the database transaction log. By indicating which changes have
already been written to the directory, checkpoint entries indicate where to begin recovery from
the transaction log, thus speeding up the recovery process.
By default, the Directory Server is set up to send a checkpoint entry to the database transaction
log every 60 seconds. Increasing the checkpoint interval may increase the performance of directory
write operations. However, increasing the checkpoint interval may also increase the amount of
time required to recover directory databases after a disorderly shutdown and require more disk
space because of large database transaction log files. Therefore, only modify this attribute if you
are familiar with database optimization and can fully assess the effect of the change.
To modify the checkpoint interval while the server is running, use the ldapmodify command line
utility to add the nsslapd-db-checkpoint-interval attribute to the cn=config,cn=ldbm
database,cn=plugins,cn=config entry.
For more information on the syntax of the nsslapd-db-checkpoint-interval attribute, see
HP-UX Directory Server configuration, command, and file reference. For instructions on using
ldapmodify, see “Adding and modifying entries using ldapmodify” (page 112).
16.2.5 Disabling durable transactions
Durable transaction logging means that the temporary database transaction log is, in fact, physically
written to disk.
When durable transaction logging is disabled, every directory database operation is written to
the database transaction log file but may not be physically written to disk immediately. If a directory
change was written to the logical database transaction log file but not physically written to disk at
the time of a system crash, the change cannot be recovered. When durable transactions are
disabled, the recovered database is consistent but does not reflect the results of any LDAP write
operations that completed just before the system crash.
By default, durable database transaction logging is enabled. To disable durable transaction
logging, use the following procedure:
1. Stop the Directory Server.
2. In the dse.ldif file, locate the entry for the nsslapd-db-durable-transactions
attribute, cn=config,cn=ldbm database,cn=plugins,cn=config. Change the default
value of this attribute to off.
3. Restart the Directory Server.
16.2.6 Specifying transaction batching
To improve update performance when full transaction durability is not required, use the
nsslapd-db-transaction-batch-val attribute to specify how many transactions will be
batched before being committed to the transaction log. Setting this attribute to a value of greater
than 0 causes the server to delay committing transactions until the number of queued transactions
is equal to the attribute value. For transaction batching to be valid, the
nsslapd-db-durable-transaction attribute must be set to on.
16.2 Tuning database performance 541