Postfix/Memory_footprint_with_large_maps

From http://archives.neohapsis.com/archives/postfix/2009-10/0931.html

It turns out the dude's smtpd processes were getting huge, like 25MiB.

The memory usage is caused by

smtpd_recipient_restrictions =
    check_client_access cidr:/etc/postfix/dnswl/postfix-dnswl-header,
    check_client_access cidr:/etc/postfix/dnswl/postfix-dnswl-permit,

This are whitelists downloaded from DNSWL every night. Each file is about 4 MBytes and bloats EACH
smtpd-process by 10 MBytes.

Aha.

From Victor:

CIDR tables are held in memory. As Wietse mentions, you can use proxymap
as a "shared-memory" cache for this.

You'll have to add smtpd_recipient_restrictions or check_client_access to the list of proxy_read_maps, I'm not sure which is correct.