Merging databases with translucent

["M. P." <kisscoolandthegangbang@hotmail.fr>]

Hi,

We are on a process of merging datas from a remote database to a local 
database. The two databases have the same base dn. To ease this process, 
I thought for a way to make a union of the remote database and the local 
database until remote datas are merged to local database. From my 
reading I found this thread 
http://thread.gmane.org/gmane.network.openldap.technical/11893 that is 
something that correspond I think to what I want.

The practical part is done on a debian jessie 8.2 with openldap 
2.4.40+dfsg-1+deb8u1 version. The local database definition is like 
this.

# Entry 1: olcDatabase={2}mdb,cn=config
dn: olcDatabase={2}mdb,cn=config
objectclass: olcDatabaseConfig
objectclass: olcMdbConfig
olcaccess: ...
olcdatabase: {2}mdb
olcdbdirectory: /var/lib/ldap/base_dn
olcdbindex: ...
olcdbmaxsize: 104857600
olclimits: ...
olcrootdn: cn=admin,dc=base,dc=dn
olcrootpw: {SSHA}.......
olcsuffix: dc=base,dc=dn
olcsyncrepl: ...
olcupdateref: ldap://master.ldap.server/

To this database definition I have added this part to make translucent 
work.

# ldapadd -Y EXTERNAL -H ldapi:/// << EOF
dn: olcOverlay=translucent,olcDatabase={2}mdb,cn=config
objectClass: olcConfig
objectClass: olcOverlayConfig
objectClass: olcTranslucentConfig
objectClass: top
olcOverlay: translucent
EOF

# ldapadd -Y EXTERNAL -H ldapi:/// << EOF
dn: 
olcDatabase=ldap,olcOverlay={3}translucent,olcDatabase={2}mdb,cn=config
objectClass: olcConfig
objectClass: olcLDAPConfig
objectClass: olcTranslucentDatabase
objectClass: olcDatabaseConfig
olcDbURI: ldap://remote-ldap.server
olcDbIDAssertBind: bindmethod="simple" binddn="cn=binddn,dc=base,dc=dn" 
credentials="onepassword" mode="self"
EOF

With this configuration, I can see on the local server, the entries that 
are available on the remote server only, an ldapsearch does not return 
entries available on the local server. Is this the normal behavior ?

Another problem is that when I restart slapd, I have an error like this

slapd[3440]: @(#) $OpenLDAP: slapd  (Sep 11 2015 15:11:55) 
$#012#011buildd@babin:/build/openldap-nFTO9j/openldap-2.4.40+dfsg/debian/build/servers/slapd
slapd[3441]: syncprov_db_open: invalid config, lastmod must be enabled
slapd[3441]: backend_startup_one (type=mdb, suffix="dc=linkeo,dc=com"): 
bi_db_open failed! (-1)
slapd[3441]: DIGEST-MD5 common mech free
slapd[3441]: slapd stopped.

I have to reload config without dn: 
olcOverlay=translucent,olcDatabase={2}mdb,cn=config and dn: 
olcDatabase=ldap,olcOverlay={3}translucent,olcDatabase={2}mdb,cn=config 
entries to make slapd start properly.

Can somebody tell me what I have done wrong ?

Thanks,
--
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M. P.