Re: Problem Using Chain Overlay, unable to figure out dontusecopy control to fix it

[Dieter KlÃnter <dieter@dkluenter.de>]

Am Tue, 29 Jul 2014 17:22:17 -0500
schrieb Andy Dorman <adorman@ironicdesign.com>:

> - Debian OpenLDAP 2.4.39 using back_mdb
> 
> - delta-syncrepl master->multiple slaves (lightning fast and has
> worked great for many years)
> 
> - the client running on each slave and causing the problem is Horde 
> using the php-ldap client (PHP 5.6).
> 
> Horde is configured to use the slave/localhost LDAP replica and we
> are hoping to use updateref and chain overlay to write to the master
> and read from the localhost slave.
> 
> Our slapd.conf global config has:
> 
> ...
> moduleload            back_ldap
> overlay               chain
> chain-uri             ldap://ldap.ironicdesign.com/
> 
> chain-idassert-bind   bindmethod="simple"
>                        binddn="root dn"
>                        credentials=<root pwd>
>                        mode="self"
> chain-return-error    TRUE
> ...
> 
> And after the syncrepl setup, the last line of slapd.conf defines
> updateref.
> 
> ...
> updateref     ldap://ldap.ironicdesign.com/
> 
> 
> So, the problem comes when we add an address book contact to be
> stored in LDAP.   The contact is written successfully to the LDAP
> master, but then Horde/php-ldap tries to get/read the new contact and
> of course it is not on our localhost slave yet, so the "get" fails.
> 
> I noted in the OpenLDAP docs, "12.3.4. Read-Back of Chained 
> Modifications", where it discusses using the "dontusecopy" control in 
> the client to prevent this problem, but I can find no reference to 
> setting this "dontusecopy" control anywhere in the PHP-ldap client or 
> any other client for that matter.
> 
> Has anyone ever used the "dontusecopy" control and if so, would you
> mind terribly telling us how/where you used it?

The php ldap module has not implemented this control.
http://php.net/manual/en/book.ldap.php
You may test the client using ldapsearch(5), read the manual page on
search extensions.

-Dieter


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Dieter KlÃnter | Systemberatung
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