Best practice for choosing RID - openldap-technical

12 Nov 2009


      Hi,
I'm moving more and more towards loading new databases via ldapadd to 
cn=config.
All databases are replicated between two mirrormode servers - including 
cn=config.
From my unserstanding I need to syncrepl directives for each database.
For cn=config it could be:
syncrepl rid=1
    provider=ldaps://<SERVER1>/
    searchbase="cn=config"
    type=refreshAndPersist
    retry="60 +"
    scope=sub
    schemachecking=on
    bindmethod=sasl
    binddn="cn=config"
    saslmech="EXTERNAL"
    tls_cert=/etc/ldap/ssl/config.crt
    tls_key=/etc/ldap/ssl/config.nopass.key
    tls_cacert=/etc/ldap/ssl/ca.crt
    tls_cipher_suite="NULL-SHA"
syncrepl rid=2
    provider=ldaps://<SERVER2>/
    searchbase="cn=config"
    type=refreshAndPersist
    retry="60 +"
    scope=sub
    schemachecking=on
    bindmethod=sasl
    binddn="cn=config"
    saslmech="EXTERNAL"
    tls_cert=/etc/ldap/ssl/config.crt
    tls_key=/etc/ldap/ssl/config.nopass.key
    tls_cacert=/etc/ldap/ssl/ca.crt
    tls_cipher_suite="NULL-SHA"
The two directives are needed since the configuration will be replicated 
and the two servers have to contain the same configuration. As long as 
Server-2 can recognize it self as <SERVER2> it will ignore the directive 
  pointing to it self - correct?
So cn=config will use RID 1 and RID 2.
When I add a new database it will also have to have 2 syncrepl 
directives, but will have to use RID 3 and RID 4 - correct?
Now, I would like not to have to specify the RID in the LDIF loaded to 
create a new database. In principle I would not know how many other 
replications were in place on the server I load it into, so it would be 
a bad thing to hardwire the RID into the LDIF for the new database.
Are there any mechanism/best practice to do chose new RIDs automatically?
/Peter