tree 947d9a1f59d259c72a6b3598e612d1d4779a04ec
parent f68da4603a092f35af627c459dbc714d9fa796e9
author Willy Tarreau <w@1wt.eu> 1244624977 +0200
committer Willy Tarreau <w@1wt.eu> 1244629412 +0200

[MEDIUM] add support for binding to source port ranges during connect

Some users are already hitting the 64k source port limit when
connecting to servers. The system usually maintains a list of
unused source ports, regardless of the source IP they're bound
to. So in order to go beyond the 64k concurrent connections, we
have to manage the source ip:port lists ourselves.

The solution consists in assigning a source port range to each
server and use a free port in that range when connecting to that
server, either for a proxied connection or for a health check.
The port must then be put back into the server's range when the
connection is closed.

This mechanism is used only when a port range is specified on
a server. It makes it possible to reach 64k connections per
server, possibly all from the same IP address. Right now it
should be more than enough even for huge deployments.