Overlay Chain

["Eudes LEDUCQ" <LEDUCQ@hec.fr>]

Hi,
 
I have founf this :
 
The chain overlay provides basic chaining capability to the underlying
database. 
What is chaining? It indicates the capability of a DSA to follow
referrals on behalf of the client, so that distributed systems are
viewed as a single virtual DSA by clients that are otherwise unable to
"chase" (i.e. follow) referrals by themselves. 
The chain overlay has significantly improved from OpenLDAP 2.2 to 2.3;
the 2.3 version: chains the URI contained in the referral instead of a
fixed URI; can use the identity assertion capability associated with
known URIs; supports the chainingBehavior control
(draft-sermersheim-ldap-chaining); can be used as global, thus allowing
to chain the updateref returned by shadow databases, resulting in
trasparent writes to slaves (either slurpd or syncrepl); note that
writes to shadow databases actually get chained to the master on behalf
of the client, and the result of the write operation that is sent back
to the client represents the response of the master to that operation.
Based on the replication policy and on replication processing time
constraints, the modification may not immediately appear on the shadow
DSA despite a successful result being returned to the client. 
The chain overlay is built on top of the ldap backend; it is compiled
by default when --enable-ldap. 
The chain overlay supports run-time configuration within the
back-config framework. 
 
is it work with Berkeley backend and openLdap 2.3.13 ? if so is some
one can give me an example ?
 
thx