Service manual

Tuning Indexing for Performance
Chapter 7 Tuning Indexing 137
The notes=U flag at the end of an access log RESULT message indicates Directory
Server performed an unindexed search. A previous
SRCH message for the same
connection and operation specifies the search filter used. The following two-line
example traces an unindexed search for
(cn=Smith) returning 10000 entries. Time
stamps have been removed from the messages.
conn=2 op=1 SRCH base="o=example.com" scope=0 filter="(cn=Smith)"
conn=2 op=1 RESULT err=0 tag=101 nentries=10000 notes=U
If you observemany such pairs for searches that should be indexed, you may be
able to improve search performance by increasing the threshold.
Changing the Index List Threshold Size
Good values for nsslapd-allidsthreshold typically fall in a range around 5
percent of the total number of entries in the directory. For example, the default
value of 4000 is generally right for Directory Server instances handling 80,000
entries or less. You may decide to set the value significantly higher than 5 percent
of the total if you expect to add large numbers of entries to the directory in the near
term, or if you expect the directory to grow considerably. You may also decide to
set the threshold differently on consumer replicas supporting many searches than
on masters supporting almost only writes. If you plan to reinitialize a large
directory from LDIF in the near term, you may even choose to adjust the value for
nsslapd-allidsthreshold just before reinitialization, as each change to the value
of this attribute requires that all indexes berebuilt. In any case, avoid setting the all
IDs threshold very high (above 50,000)even for very largedeployments unlessyou
have a good, specific reason for doing so.
Change the all IDs threshold as follows. Note that service is interrupted on the
Directory Server instance undergoing the change.
1. Stop the Directory Server instance in question.
2. Export all directory databases to LDIF.
Refer to the Sun ONE Directory Server Administration Guide for details.
3. Carefully adjust the value of the nsslapd-allidsthreshold attribute in
ServerRoot/slapd-ServerID/config/dse.ldif.
4. Reinitialize all directory databases from LDIF.
Refer to the Sun ONE Directory Server Administration Guide for details.