[PATCH] Assert that the objectClass is always present

Arvid Requate requate at univention.de
Tue Mar 11 10:37:05 MDT 2014


On Fri, 2014-02-28 at 17:51:43 +1300, Andrew Bartlett wrote:
> Metze and Arvid,
> What do you think of the attached, to try and ensure the objectClass
> missing bug can't be propagated?

On Sat, 2014-03-01 at 07:49 +1300, Andrew Bartlett wrote:
> If that is how this corruption happens, then while disturbing, this also
> suggests that the fix is to force re-replication, not to delete the
> object, as on at least one DC, the whole correct object exists.  Anyway,
> the new assertions in the patches should help with detecting this, as we
> won't accept the object without an objectclass any more.

Ok, how will drepl behave after the new assertion has been triggered? Will 
this block replication full stop or will it cause the object to be neglected 
or will it try tro re-replicate the object in the next replication run?

* If the patch brings replication to a grinding halt that would be a show 

* Neglecting the entire object in replication might also cause additional 
inconsistencies (think group membership or other backlinks), but maybe it's 
better than forcing samba to swallow a broken object which it cannnot digest 
anyway. I cannot rate the impact such a broken object would cause in other 
parts of samba. Segfaulting processes are definitely not good either, but the 
impact is more isolated than a stopped replication. A segfault usually doesn't 
go unnoticed, a stopped replication may go unnoticed for too long time. And 
the cause might be harder to identify.

* The third option, re-replication, would be ideal, obviously, if it doesn't 
lead to an infinite circle.

Felix already commented on the other points. I may add that we have seen 
missing objectclasses in four different environments.


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