Antw: delta sync and strictrefresh

["Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de>]

>>> "A. Schulze" <sca@andreasschulze.de> schrieb am 08.03.2016 um 21:13 in
Nachricht <20160308211316.Horde.GypvzvjbSnE4DU4U3p33UA1@andreasschulze.de>:

> Hello,
> 
> I'm a longtime openldap and syncreplica user. Now I learned about  
> delta replication and the option "strictrefresh".
> But it doesn't work as promised. Maybe my expectation is simply wrong...
> 
> Let's describe my use case:
> One ore two provider serve data to numerous consumer.
> Application running on the consumer host are configured to query the  
> local consumer first
> and fall back to the provider. A typical LDAP-URI looks like  
> "ldap://localhost ldaps://provider1 ldaps://provider2"
> Application only /read/ data.
> 
> Sometimes it happen the consumer go out of sync. Convenient solution:  

What you describe is not a database out of sync, but a corrupted database. You never have to delete a database that is out of sync; you'll just have to refresh it, and that should be automatic if configured and working correctly

> delete the consumer ldap database and restart slapd. Now it take some  
> time to fetch the whole data from provider to consumer server.

It would be definitely helpful to have a diff of the databases (between up-to-date, and outdated).

> 
> Just in this time frame the application may query ldap://localhost and  
> get an answer which is simply wrong
> because the data transfer is still in progress. That's what I want to avoid.

What you did not say is who is updating the data, and where.

> 
> Is that possible with openldap at all

"time was invented in universe so that not everything would happen at once" (vague memory of som UNIX fortune cookie) ;-)

Regards,
Ulrich