xr(1) Crossroads Load Balancer & Fail Over Utility


xr [--verbose] [--web-interface XRSERVER:PORT] --server tcp:XRSERVER:PORT --backend BACKEND:PORT [--backend BACKEND:PORT] ...


This manual page briefly documents XR, the Crossroads Load Balancer & Fail Over Utility.

XR is an open source load balancer and fail over utility for TCP based services. It is a dae mon running in user space, and features extensive configurability, polling of back ends using wake up calls, status reporting, many algorithms to select the 'right' back end for a reques t (and user-defined algorithms for very special cases), and much more.

XR is service-independent: it is usable for any TCP service, such as HTTP(S), SSH, SMTP, dat abase connections. In the case of HTTP balancing, XR handles multiple host balancing, and can provide session stickiness for back end processes that need sessions, but aren't session-awa re of other back ends.

XR furthermore features a management web interface and can be run as a stand-alone daemon, or via inetd.

Execute 'xr -h' to get a complete list of available command-line parameters.


xr --verbose --server tcp:0:80 --backend --backend --backend 10.1.1. 3:80 --web-interface 0:8001

This instructs XR to listen to port 80 and to dispatch traffic to the servers, and, port 80. A web interface for the balancer is started on port 8001.

Direct your browser to the server running XR. You will see the pages served by one of the three back ends. The console where XR is started, will show what's going on (due to the presence of --verbose).

Direct your browser to the server running XR, but port 8001. You will see the web interface, which shows the status, and where you can alter some settings.


XR was written by Karel Kubat <[email protected]>. Web page: http://crossroads.e-tunity.com

This man page was written by Frederik Dannemare <[email protected]>.