Re: back-config delete support (syncprov overlay)

[Ralf Haferkamp <rhafer@suse.de>]

Am Freitag 26 Februar 2010 19:29:43 schrieb Howard Chu:
> Ralf Haferkamp wrote:
> > Am Freitag 26 Februar 2010 13:30:55 schrieb masarati@aero.polimi.it:
> >>> Hi,
> >>> 
> >>> while taking up some loose ends on my work on delete support for
> >>> back- config (enabled with -DSLAP_CONFIG_DELETE) I wondered how we
> >>> should deal with the deletion of the syncprov overlay when there
> >>> are active refreshAndPersist sessions. What errorcode should we
> >>> sent when closing such a connection? To me LDAP_UNAVAILABLE sound
> >>> like the best choice. LDAP_UNWILLING_TO_PERFORM might also be ok.
> >> 
> >> What about an unsolicited notification (RFC 4511, 4.4)?
> > 
> > Hm, yes. A "Notice of Disconneciton" might work as well. But that
> > would result in the client connection been taken down, which is
> > probably not desired. For syncrepl connections from slapd-consumers
> > this might be ok. But other LDAPSync clients might have other
> > operations active on the same connection which wouldn't be affected
> > by the removal of the syncprov overlay, I guess.
> > 
> > Returning an error just for the LDAPSync related Search seemed more
> > logical to me.
> 
> Agreed. The actual choice of error probably isn't too critical.
> LDAP_UNAVAILABLE sounds fine.
> 
> Also on the topic of deletes, we should start adding term_module()
> handlers to the backends and overlays.
Yes. I havn't gone into the details of module unloading yet, though.

An additional bi_db_delete handler in the BackendInfo structure might be 
helpful as well. Or a flag passed to  bi_db_close/bi_db_destory to 
indicate whether the database/overlay is closed due to a server shutdown 
or a delete operation on cn=config.

-- 
Ralf