Date: Mon, 19 Feb 2007 14:08:16 -0800
From: Pete Rowley <prowley(a)redhat.com>
This is a feature that exists in OpenLDAP (but has no RFC that I am
aware of).
Heimdal uses this feature exclusively for its directory interactions (making it
incompatible with other LDAP directories), and Samba testing is often performed
over unix domain sockets (a convenience for them). There are advantages: no TCP
overhead for local connections
This turns out to be pretty significant too - using TCP connections to
localhost, a connection soak test will use up all available port numbers in a
matter of seconds, after which all connection attempts fail. (Because there
is a mandatory 2MSL timeout before a closed port may be made available for
reuse.) Using ldapi we can process thousands of connections per second
indefinitely. (Perhaps someone ought to suggest to the kernel folks that a
2MSL timeout on loopback sockets is unnecessary, since presumably the TCP
close handshake can't get misrouted/lost there. ;)
--
-- Howard Chu
Chief Architect, Symas Corp.
http://www.symas.com
Director, Highland Sun
http://highlandsun.com/hyc
Chief Architect, OpenLDAP
http://www.openldap.org/project/