postfix LDAP lookup caching

Hi,

We've some MTAs under quite big load. Since there're several MTAs (not
only postfix) on different operating systems as well, we use LDAP as
a "common language" between systems, and of course to keep result of
table loopups in sync (with LDAP replication for local ldap servers).

However it seems the quite big load generating rapid amount of LDAP queri=
es
is not handled fast enough by LDAP servers. So it would be nice if the
result of the lookup would be cached by Postfix (caching for maximum of
10sec is quite good, modifications in LDAP structure does not a problem i=
f
it realizes within about one minute or so). However as I read from the
documentation, caching function in LDAP lookup handler was dropped. I've
tried to use proxymap as well, but as far as I understand that is not for
caching only for proxying for security and/or lowering the number of
multiple queries with sharing the same connection through.

So my problem remains: how can I cache lookup results? The wild idea will=
be
to use local eg hash maps (which are faster for simple lookups than using
ldap I guess) and use some perl or shell backend functionality in OpenLDA=
P
to update that hash maps regurally when modification arrives via LDAP
replication from the master LDAP server.

Note, that eg recipient check on the inbound mail server requires quite
large (>100K) but linear table besides transport map definitions and so.

Please give some hint if there's better soultion for this.

--=20
- G=E1bor (larta'H)