Re: syncrepl questions

[Jonghyuk Choi <jongchoi@us.ibm.com>]

>Both servers are loaded with the exact same databse, with have the entryCSN 
>for all entries.  I then made a _single_ change to the master.

I'll soon commit the replica promotion / demotion patch for the slaptools that I talked about.

>So, if I have a database with 5 million entries, it is going to send along 
>1 change + 4,999,999 ID's of unchanged entries?

Yes. 
The revised (soon too be published) LDAP Sync protocol has two modes.
One is state-based (sending add+present) and the other is log-based (sending add+delete).
If OpenLDAP becomes capable of maintaining history store
then the Syncrepl engine will be enabled to switch between the two modes
depending on the consumer's state. If the consumer state is recent enough
to be covered by the history store, then only changes would be sent if it is more efficient.
If the consumer state cannot be covered by the history store, then the additive changes
and IDs of present entries will be sent, which is far more efficient than a full reload.
On the other hand, the LCUP proposal only supports the log-based mode.
So, without the history store, full reload would be a frequent event.

------------------------
Jong Hyuk Choi
IBM Thomas J. Watson Research Center - Enterprise Linux Group
P. O. Box 218, Yorktown Heights, NY 10598
email: jongchoi@us.ibm.com
(phone) 914-945-3979    (fax) 914-945-4425   TL: 862-3979