Matt Shields wrote:
Data changes too frequently to generate the file every x number of minutes across all smtp servers.
You have to support instantly deliverable mailboxes for new accounts?
The mysql db isn't a single server. It's a master (read/write) with multiple replicas for read access. Those replicas are load balanced with LVS (heartbeat/ldirectord/ipvsadm). The postfix(smtp) incoming and outgoing servers are also load balanced with LVS. So database read speed is not an issue. Believe me, we know how to build large high traffic sites, the only problem we're having is the exact syntax on using transport_maps or virtual_transport with multiple lmtp transports, and I think I got that figured out with the transport_maps. Will post more later.
I assume that you are aware that transport_maps is called multiple times.
Recipient_maps in rdbms tables generate at least two lookups (one for smtpd, one for cleanup) but when you add transport_maps, that will at least explode to one per subdomain of the sender address (you can mitigate a lot of that with the domain setting in the map configuration file) as trivial-rewrite tries to build its triples for addresses.