I'd consider providing a mechanism (e.g. a sort of generalization of
backover.c) that allows those overlays that use internal databases and
are willing to allow overlay stacking to inject a slap_overinfo
structure in place of the original BackendInfo; then, something like
proxycache-overlay syncprov
proxycache-syncprov-sessionlog 100
could be used to access the configuration of that overlay. By using a
hierarchical configuration directive pattern we should be able to
propagate this to an arbitrary number of layers. The directives would
look quite odd, but at least we don't need to change the style of the
configuration; of course, nested parentheses would be a big plus:
database ldap
overlay proxycache {
proxycache hdb ...
overlay syncprov {
sessionlog 100
}
}