Thanks Howard.
I had already put in my DB_CONFIG file this values
set_lk_max_locks 2000
set_lk_max_lockers 2000
set_lk_max_objects 2000
Just double value, by default I've read it was 1000. Do you refer
this when you recommend me that page(
http://www.openldap.org/faq/data/cache/893.html)?
But number of lockers increase day by day ... now its value is about
250 but in two weeks my OpenLDAP will get 2000 lockers because this
value never decrease. And then my OpenLDAP will crash beause of this
error "Lock table is out of available locker entries". This force me
to run db_recover almost twice a month.