connection pooling in back-ldap?

[Kartik Subbarao <subbarao@computer.org>]

I'd like to be able to collapse several incoming LDAP connections into a 
single proxy connection (or a small pool of proxy connections) with 
back-ldap. I noticed that this doesn't seem to be possible with the 
current back-ldap implementation, but was wondering if it's possibly 
being considered as an enhancement?

Here's the scenario, to better explain what I'm looking to do. I'm 
working with postfix, which is pretty greedy with opening up LDAP 
connections. Each instance of a postfix SMTP process can have several 
connections open to the specified LDAP server. In reality, all of these 
connections perform extremely trivial searches (filter is something like 
mail=foo@host.com, retrieving a mailRoutingAddress type attribute). I'd 
like to shield my real LDAP servers from receiving all of the direct 
connections from the individual postfix processes. So, I was looking to 
point postfix to, say, localhost:3890, which would be an openldap proxy 
running back-ldap. And then the back-ldap would proxy to ldap.corp.com 
on the back end.

Here's a rough sketch:

postfix conn=1, op=1 : filter=(mail=abc@host.com)
postfix conn=2, op=1 : filter=(mail=def@host.com)
postfix conn=3, op=1 : filter=(mail=ghi@host.com)

These connections are made to the back-ldap proxy by postfix. The 
back-ldap proxy should turn this into the following (in the case of a 
single pooled connection):

proxy conn=1, op=1 : filter=(mail=abc@host.com)
proxy conn=1, op=2 : filter=(mail=def@host.com)
proxy conn=1, op=3 : filter=(mail=ghi@host.com)

Is something like this possible? Any interest in adding it to the 
back-ldap functionality? I know I could probably hack my own with 
back-perl or somesuch, but it'd be nice to have this feature :-)

Thanks,

	-Kartik