NAME¶
fair
—
simple TCP load balancing service
DESCRIPTION¶
fair
is a load balancer for TCP connections.
It can be used to distribute incoming connections for SMTP, HTTP or any other
TCP service to multiple hosts, distributing the load as evenly as possible.
fair
consists of two daemons. The
carrousel
is the front-end; it keeps track
of back-end hosts and their status, and forwards incoming connections to the
back-ends in such a way that the load is distributed fairly. The
transponder
runs on the back-end hosts, it
registers with the carrousel and sends it status information. The TCP
connections forwarded by the
carrousel
are
not sent to the
transponder
daemons but are
sent directly to the desired service running on the back-end host. Both
daemons share a single configuration file.
EXAMPLES¶
The following example shows how to set up
fair
to service HTTP connections and to
distribute them over back-ends in the 192.168.1.0/24 subnet.
The configuration file
/etc/fair.conf
contains the following:
WorkerService = http
BalancerService = http
AllowUDP = ^192.168.1.[0-9]+$
On
www.example.com, the front-end server
receiving the incoming HTTP connections, just run:
On each of the back-ends run:
transponder www.example.com
SEE ALSO¶
carrousel(8),
transponder(8),
fair.conf(5)