Re: Issues with syncrepl and mirrormode

[Howard Chu <hyc@symas.com>]

Pierangelo Masarati wrote:
> Pierangelo Masarati wrote:
> > I've backed out RID, which is now decimal again (0..999), and let sctxcsn
> > be NULL when no maxcsn can be gathered.  In this case, after running
> > test050 and leaving the directories in place, if I restart the two servers
> > and perform an add as the first operation, the server acting as a consumer
> > crashes both in refreshOnly and in refreshAndPersist modes (I plan to
> > modify the test in order to trigger this case, so we can track regressions
> > once it's fixed).  My question is now:
> >
> > 1) is it correct that syncprov_op_response() is set up at all for those
> > modifications that come from the producer?
>
> Obviously yes, to enable cascaded replication
>
> > 2) If it is, should maxcsn be available?
>
> don't know yet
>
> > 3) If not, how should its absence be dealt with?
>
> it should definitely be dealt with: cascaded replication incurs into
> this issue; after adding cookie logging, testrun/slapd.4.log after
> test019 is full of
>
> syncprov_sendresp: cookie=rid=001,csn=

This is probably an artifact of syncprov_qresp() which always allocates at 
least one byte for the queued CSN, thus the bv_val is never NULL. Which is why 
the test in compose_sync_cookie() was supposed to check BVISEMPTY, not BVISNULL.

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