Red Hat Directory Server 8.0 Configuration, Command, and File Reference

This performance tuning-related attribute automatically sets the size of the import cache
(importCache) to be used during the command-line-based import process of LDIF files to the
database (the ldif2db operation).
In Directory Server, the import operation can be run as a server task or exclusively on the
command-line. In the task mode, the import operation runs as a general Directory Server
operation. The nsslapd-import-cache-autosize attribute enables the importCache to be set
automatically to a predetermined size when the import operation is run on the command-line.
The attribute can also be used by Directory Server during the task mode import for allocating a
specified percentage of free memory for importCache.
By default, the nsslapd-import-cache-autosize attribute is enabled and is set to a value of
-1. This value autosizes importCache for the ldif2db operation only, automatically allocating
fifty percent (50%) of the free physical memory for importCache. The percentage value (50%) is
hardcoded and cannot be changed.
Setting the attribute value to 50 (nsslapd-import-cache-autosize: 50) has the same effect
on performance during an ldif2db operation. However, such a setting will have the same effect
on performance when the import operation is run as a Directory Server task. The -1 value
autosizes importCache just for the ldif2db operation and not for any, including import, general
Directory Server tasks.
NOTE
The purpose of a -1 setting is to enable the ldif2db operation to benefit from
free physical memory but, at the same time, not compete for valuable memory
with entryCache, which is used for general operations of the Directory Server.
Setting the nsslapd-import-cache-autosize attribute value to 0 turns off the importCache
autosizing feature - that is, no autosizing occurs during either mode of the import operation.
Instead, Directory Server uses the Section 4.1.22, “nsslapd-import-cachesize” attribute for
import cache size, with a default of 20,000,000.
There are three caches in the context of Directory Server: dbCache, entryCache, and
importCache. importCache is only used during the import operation. The
nsslapd-cache-autosize attribute, which is used for autosizing entryCache and dbCache, is
used during the Directory Server operations only and not during the ldif2db command-line
operation; the attribute value is the percentage of free physical memory to be allocated for
entryCache and dbCache.
If both the autosizing attributes, nsslapd-cache-autosize and
nsslapd-import-cache-autosize, are enabled, ensure that their sum is less than 100.
Parameter Description
Entry DN cn=config, cn=ldbm database, cn=plugins,
cn=config
Database Attributes under cn=config,
145