Re: Index Usage

[masarati@aero.polimi.it]

> On 12/21/2010 07:26 AM, Quanah Gibson-Mount wrote:
>> --On Monday, December 20, 2010 12:44 PM -1000 Paul <paul@ehawaii.gov>
>> wrote:
>>
>>> I'm also seeing odd entries in the ldap logs:
>>>
>>> Dec 20 11:21:17 <server> slapd[11171]: <= bdb_equality_candidates:
>>> (objectClass) index_param failed (18)
>>> Dec 20 11:21:17 <server> slapd[11171]: <= bdb_equality_candidates:
>>> (objectClass) index_param failed (18)
>>> Dec 20 11:21:17 <server> slapd[11171]: <= bdb_equality_candidates:
>>> (gidNumber) index_param failed (18)
>>
>> This means those entries are being searched on with a search other
>> than the way they are indexed.  No amount of re-running slapindex is
>> going to change those messages.
>
> Sorry, I may be being completely dense here.  So those errors are
> because the wrong type of index is being specified in these lines in my
> config file?
>
> index           objectClass                     pres,eq
> index           gidNumber                       eq
>
> I assumed that "bdb_equality_candidates" would indicate "eq" indexing as
> being the type of search it's trying to do, is my assumption off the mark?

Your assumption is correct.  You don't need to index "objectClass" for
"pres", as the objectClass attribute is always present, "eq" suffices.  If
you changed the "index" directive in slapd.conf you need to run slapindex
while slapd is not running.  Make sure you run slapindex with the correct
identity, as all index files will be generated with that identity, and
then slapd needs to be able to read them.

> On the general subject of indexes, is there a way to identify in
> OpenLDAP/slapd which ones are actually being used?  Beyond just basic
> pam/e-mail stuff I've got a number of java apps and the like not all
> done in house that could be querying the LDAP server in numerous ways.

You can enable monitoring (configure the monitor database in slapd.conf),
and check the contents of olmBDBNotIndexed in the database entry (e.g.
"cn=Database 1,cn=databases,cn=monitor" if the BDB database is the first
one); to use this feature, you need to #define BDB_MONITOR_IDX and
recompile slapd.  You'll get data like

olmBDBNotIndexed: description#present=1#substr=1

indicating that "description" was searched once with "present" and once
with "substring" and they were not indexed.

p.