Glueing together backend databases - meta, glue or chain?

[Pieter Baele <pieter.baele@gmail.com>]

Hi,

I have several backend databases on my master servers, and need to
present a combined view to clients on slaves (Unix authentication)
I think this a common question/issue...

Scenario: 5 backend DB's, 2 of these are needed on each slave server
Each of these has an ou=Groups,ou=Nodes, ou=People etc.

--- dc=common,dc=example,dc=org
--- dc=shared,dc=example,dc=org
--- dc=companyA,dc=example,dc=org
--- dc=companyB,dc=example,dc=org
--- dc=companyC,dc=example,dc=org

So one of the slaves uses companyA, common and shared
another one uses companyB, commmon and shared
and the last one companyC, common and shared

all slaves represent this as "dc=example,dc=org"

The easiest way seems using meta backend, but I've the feeling this
has drawbacks??? You can't use cn=config, performance?

Maybe there is an approach with chain or glue?
I can change my DIT if necessary.

Sincerely, Pieter