you may find additional functionality for widely used solutions that is minimizing the risks that you mentioned (e.g. a replication of databases instances).

but probably you will not find anything for the ruby blackboard rinda to make it fail-over and/or scalable - but it is not because the blackboard is a bad concept or idea, it is about missing additional tools, that would help you to start more instances, that would replicate the actual state over the started instances, would be able to detect a failed instance, propagate that event and handle it somehow…

there are several tuple space implementations, some of them even commercial, that provide some features in this area, e.g. gigaspaces, but it is for java and .net.

rinda, a ruby blackboard implementation, is ok. with general monitoring tools, like monit, you will get a nicely working solution. but if you need more, probably you should check another implementations.

bye