This is related to questions/comments in Issue #154. There's currently no automatic, built-in "failover" mechanism in the future framework.
Here's a minimal reproducible example that emulates an R worker going down:
f<- future( quit("no") )
# Error in unserialize(node$con) : # Failed to retrieve the value of MultisessionFuture from cluster node #1 (on 'localhost'). The reason reported was 'error reading from connection'
As a first step, what needs to be added to the future framework is a way to distinguish this type of errors from regular errors produced from evaluating the future expression itself. This minimal extension is on my todo list.