Re: Sync replication failure during startup.

[Howard Chu <hyc@symas.com>]

Stelios Grigoriadis wrote:
> Howard Chu wrote:
> > Stelios Grigoriadis wrote:
> > > The output from one run. I haven't had the time to look at it yet.
> > The key question is, do any of these debug messages correspond to
> > entries that you've found are missing on the replicas?
> >
> > > Entry cn=dlt30604-0,dc=example,dc=com CSN
> > > 20071005135356Z#00000e#00#000000 greater than snapshot
> > > 20071005135356Z#00000d#00#000000
> The entries that are missing from the replicas are the ones with
> "greater than snapshot". I commented
> out the if-statement around line 1869 in syncprov.c and couldn't
> reproduce the problem.
>
> On a side note, if an exception would be made for refresh and persist
> and send results greater than
> the snapshot:ed ctxcsn, what are the side effects of this? Is it
> possible to get "ghost" entries in the replicas?
> Suppose that an add operation fails to commit but the entry is already
> replicated, is that possible?

No, not possible. The backends will not return uncommitted entries in search 
responses.

The only possible side-effect is that the replicas may receive some entries 
twice if they are picked up during both the refresh phase and during the 
persist phase. That is, it will consume a little extra network bandwidth.

I'm looking at restructuring the search code to try to avoid this duplication.
--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/