Slow adding attributes to a entry with many attributes

[Ariel Malves <almalves@gmail.com>]

Dear list.

In the past 4 days I have had problems with OpenLdap, running a Samba
PDC solution.

My PDC has about 3000 users, migrated from a Netware 5 with
eDirectory. Each user is in a primary and a secondary group too
(Students and Domain Users groups). I could see a very fast increasing
of log size (log.000000*) when adding users to secondary groups. For
each new memberUID attribute added to the group, the log grows about 7
mb! The time for this operation is very bad too, about 3 seconds.

Searching in archive of this list I found a message from other user
with same problem (
http://www.openldap.org/lists/openldap-software/200407/msg00446.html),
and the recommendation was to upgrade the version of OpenLdap to 2.2.*
and BDB to 4.2.52, but I already have those versions in my Debian
Sarge (stable).

Well, my question is: Is this normal?

I have tried changing the backend from bdb to hdb with slapcat &
slapadd, but nothing changed.

The only little performance improvement was when I create a DB_CONFIG
with the following attributes:

set_cachesize 0 300000000 10
set_lg_regionmax 262144

set_lg_bsize 2097152


set_flags DB_TXN_WRITE_NOSYNC

I tried another simulation in a clean ldap installation, creating a
unique person (inetOrgPerson) and adding many (2000+) mail addresses
to it and the results was similar: an intensive I/O on logs and the
operation of adding new attributes slowing down each time.

I have thought about a workaround: don't put these students in a
secondary group, but manage rights access to files would become
difficult a bit.

Please, if anyone has an idea, tell me.

Thanks to all, and sorry my poor English.