Re: Syncrepl and chain Overlay

[Ralf Haferkamp <rhafer@suse.de>]

On Friday 10 December 2004 15:33, Pierangelo Masarati wrote:
> > On Thursday 09 December 2004 21:03, Pierangelo Masarati wrote:
> >
> > I added those directives, but that didn't bring any progess. The
> > behaviour is
> > still the same. I got a bit further by using the chain overlay as a
> > global overlay
>
> mmmmh, that global overlay stuff needs some review; I mean, for write
> operations I suspect some of the data consolidation should occur earlier
> so that regular overlays can be injected as global.

Ok I didn't know that, thanks for clarifying.

> Otherwise, global 
> overlays need to be specifically designed to work as such.  This does not
> defeat their purpose, that is the capability of manipulating requests
> before a database is selected, but does not work toward reducing code
> duplication.
>
[..]
> > Seems that Quanah is right and this part of HEAD is a bit unstable at the
> > moment.
>
> I'v ebeen playing with the chain overlay recently (see my fixes this week)
> and it worked well alone.  There might be some isses in cooperating with
> the syncrepl.  Did you try reversing the overlay stacking order?

I am not using any other overlays than chain. I might be wrong here but isn't 
the syncprov overlay only needed on the provider side? 
Anyway, I've removed all the syncrepl related stuff from my config and 
inserted a normal referral into the database. With that the chain overlay 
seems to work fine. So seems to be indeed some integration issue with 
syncrepl.

If I understand the code correctly over_op_modify() is never called when the 
chain-overlay is used on a syncrepl-consumer. So it hasn't any chance to set 
op->callback correctly. The referral is send directly from fe_op_modify() an 
op->callback is set to NULL. So the overlay can't intercept the Referral. On 
the other hand I might just misinterpret the whole code ;)

Maybe we should move thread this to openldap-devel now.

-- 
Ralf Haferkamp
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