try{
    parallel a: {
        execute_function('A')
    }, b: {
        execute_function('B')
    }, c: {
        execute_function('C')
    },
    failFast: false
} finally {
    stage 'Cleanup'
    echo "done with all"
}

def execute_function(name){
    try { 
    	stage "${name}"
	    node {
    	    if(name == 'B'){ echo "FAILING HERE"; error 'died' } 
    	    else if (name == 'A') { echo "sleeping"; sleep 25; }
    	    echo "future steps"
	    }
    } catch(e) {
    	echo "error: ${e.toString()}"; throw e
    }
}

[a] Entering stage A
[a] Proceeding
[Pipeline] [a] Allocate node : Start
[a] Running on master in /var/lib/jenkins/workspace/failfast
[Pipeline] [b] stage (B)
[b] Entering stage B
[b] Proceeding
....
[a] sleeping
[Pipeline] [a] sleep
[Pipeline] [b] echo
[b] FAILING HERE
[Pipeline] [b] error
[Pipeline] } //node
[Pipeline] [c] echo
[c] future steps
[Pipeline] } //node
[Pipeline] Allocate node : End
[Pipeline] Allocate node : End
[Pipeline] echo
error: hudson.AbortException: died
[Pipeline] } //parallel
[Pipeline] } //parallel
[Pipeline] [a] echo
[a] future steps
....
Entering stage Cleanup
Proceeding
[Pipeline] echo
done with all
[Pipeline] End of Pipeline
org.jenkinsci.plugins.workflow.cps.steps.ParallelStepException: Parallel step b failed