Crossroads is a daemon that basically accepts TCP connections at preconfigured ports, and given a list of back ends distributes each incoming connection to one of the back ends, so that a client request is served.
Additionally, Crossroads maintains an internal administration of the back end connectivity: if a back end isn`t usable, then the client request is handled using another back end.
Crossroads will then periodically check whether a previously not usable back end has come to life yet. Also, Crossroads can select back ends by estimating the load, so that balancing is achieved.
Using this approach, Crossroads serves as load balancer and fail over utility. Crossroads will very likely not be as reliable as hardware based balancers, since it always will require a server to run on. This server, in turn, may become a new Single Point of Failure (SPOS).
However, in situations where cost efficiency is an issue, Crossroads can be a good choice.
Furthermore, crossroads can be deployed in situations where a hardware based balancing already exists and augmenting service reliability is needed. Or, crossroads may be run off a diskless system, which again improves reliability of the underlying hardware.
This document describes how to use crossroads, how to configure it in order to increase the reliability of your systems, and how to compile the program from its sources.
What`s New in This Release: [ read full changelog ]
· Promoted to STABLE. A word of warning: DOS protection under high load may be unstable, currently under investigation.
