On Tue, Aug 05, 2025 at 12:50:44PM +0000, Windl, Ulrich wrote:
> Hi!
> 
> I have a support case from SUSE's version of slapd open, and I wonder
> about one specific statement from support:
> 
> A core dump is triggered by
> 
> syncprov.c:2360:
> 
> assert( !BER_BVISEMPTY( &oldestcsn ) && !BER_BVISEMPTY( &newestcsn ) &&
>         ber_bvcmp( &oldestcsn, &newestcsn ) < 0 );
> 
> Support explained: "Any of these indicates the changelog (accesslog)
> is in a completely inconsistent or corrupted state."

Hi Ulrich,
based on what have they concluded this? There is very little to go on in
what you've provided here.

Again as with all reports of crashes and desyncs, please file an ITS at
bugs.openldap.org or encourage them to do so:
- if you can reproduce the issue with sample data, please provide a way
  to do so, this is universally the best way to ensure we can diagnose
  and address a bug
- provide as much information as possible, at a minimum relevant parts
  of configuration, "sync"-level logs, ... from all servers involved
- provide the values of contextCSN and minCSN on the main and accesslog
  DBs on all the servers involved (in addition to the logs from that
  event)

Without this you're just hoping someone else encounters this issue and
does the right thing of giving us the information we need to isolate it.

> The support recommends to reset the CSNs by disabling any replication
> (which doesn't remove those IMHO) and "either using syncrepl or
> delta-syncrepl, but not mixing both.":
>
> I don't see a problem if one dependent server gets the changed through
> "classic methods" (e.g. Refresh), and another server gets updates
> through delte-syncrepl. Am I wrong?

Stating "either using syncrepl or delta-syncrepl, but not mixing both."
sounds concerning. You haven't provided any sort of configuration
snippets or even basic description of your set up to say if we should be
concerned about this.

Are these servers also providers? All providers need to have *identical*
configuration and *full* read access to other provider's DB (both main
DB and accesslog if used).

> Finally support concludes: "Please note that these types of
> replication integrity issues do not affect 389 Directory Server, which
> uses a more robust mechanism for change tracking and includes a proper
> Lamport clock implementation."

AFAIK 389DS replication is push based, so the design and behaviours are
quite different. Also assuming we're looking at the above, their comment
seems somewhat random in context.

> Well, I actually tried 389DS, but the conversion tool was highly
> incomplete, the schemata and ACL mechanism were completely different,
> and there was not a single current book for it available, so I
> resigned.

Regards,

-- 
Ondřej Kuzník
Senior Software Engineer
Symas Corporation                       http://www.symas.com
Packaged, certified, and supported LDAP solutions powered by OpenLDAP

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