Re: delete members in big groups with back_mdb

[Howard Chu <hyc@symas.com>]

Marco Schirrmeister wrote:
> Hi,
>
> I have a problem with mdb and modify operations on very large groups. Specifically deleting members from those groups.
> Removing 10 members from a group with 25000 members takes 23 seconds. Which also means, all other clients that want to do something hang.
> Deleting a user from multiple big groups takes minutes before it finishes.
> Adding members to a large group is quick though.
>
> When this delete is running, the cpu goes also up to 100%.
>
> It looks like it has to do with the index that I have on uniqueMember.
> If I remove the index on uniqueMember, the delete of members in big groups is fast.
>
> System details are
> CentOS 6 64bit
> OpenLDAP 2.4.35
> slapd.conf below
>
> Is this something normal/exptected or is it maybe a bug?

Read slapd.conf(5) manpage, sortvals keyword.

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/