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Re: backend requirements for syncrepl

Jong-Hyuk wrote:

I am currently into
the design of a changelog-based operatoin mode of syncrepl. Wondering
whether this would be sufficient for your case.
- Jong-Hyuk

I'd like to hear more about this, since we are in the process of implementing changelog functionality as well.

One of the weaknesses we see in the current syncrepl implementation is that the syncrepl consumer must always retrieve complete entries for any changes that have occurred on the master. The network overhead can get large for a large number of changes to large entries. Our approach to solving this is to create a changelog on the master which is a database whose entries consist of LDIF modification records. The changelog is written using an overlay on the real database of interest, and the changelog database becomes the syncrepl provider. So the syncrepl protocol doesn't change, but there is a new syncrepl consumer that reads these entries and turns them into the appropriate LDAP operations.

 -- Howard Chu
 Chief Architect, Symas Corp.       Director, Highland Sun
 http://www.symas.com               http://highlandsun.com/hyc
 Symas: Premier OpenSource Development and Support