Re: ReW: (ITS#4622) syncrepl operations incomplete when consumer rest arted

[hyc@symas.com]

Halbritter, Matthias wrote:
>> I don't understand what issue you're reporting. The syncrepl consumer
>> always restarts when the consumer server is stopped and restarted. What
>> does REFRESH_DELETE have to do with anything?
>>     
>
> I apologize if my explanations are misleading or may somehow seem opaque.
> Let me try to clarify this issue:
>
> I do not want to state that the consumer server itself or the syncrepl
> consumer service do not restart. That works fine. The issue I am reporting
> is that the syncrepl consumer restarts without recognizing that it still has
> an unsynchronized database.
>   

OK, I see what's happening here. The contextCSN from the provider got 
replicated already, so the consumer thinks that's the current valid 
contextCSN. When it starts up and talks to the provider, it matches the 
provider's current contextCSN, which ordinarily means no updates are 
needed, so nothing happens.

The workaround is to start the consumer slapd with the "-c" option to 
make it ignore the database's contextCSN, and allow it to restart the 
Refresh phase.
> An example: There's a syncrepl provider with about 5,000 entries in its
> database and there's a syncrepl consumer with an empty database. Having
> started the consumer in syncrepl refreshAndPersist mode it will correctly
> start retrieving the missing 5,000 entries (that's where the debug output on
> the consumer with -d 16384 shows a REFRESH_PRESENT line and a whole lot of
> LDAP_SYNC_ADD operations afterwards). Now, let us - say after around 500
> entries - cleanly stop the consumer. (No problem so far.) But after starting
> the consumer again it will show no sign of trying to retrieve the missing
> 4,500 entries (here's where the debug output shows a REFRESH_DELETE line and
> that's it).
> Going from here I may delete entries on the provider which are changes
> passed on to and processed by the consumer - but still no sign of retrieving
> the still missing entries.
>
> I hope I could clear things up a bit.
>
> Matthias Halbritter
-- 
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc
  OpenLDAP Core Team            http://www.openldap.org/project/