May be related to 

1. JENKINS-40771

In the following situation, we have a single job that runs a function which requires a node.

Upon restart the job consumes 1 more mode than expected.

I expect only a single node to be used at any time.  Before restart this is the case, after restart this is not.

The additional node is consumed until the parallel call is finished.

If this additional node happens to be the only available node then the pending jobs will be stuck waiting for executor.

Pictures attached.

To reproduce:

1. Run the following pipeline script
2. Once its running restart server
3. Observe the build queue

This has been tested using the windows service and running from the cmdline using: "java -jar jenkins.war --httpPort=8082"

def run_function (String words){
  return {
    node (){
      sleep(300)
      println words
    }
  }
}
Map parllel_map
node () {
  println "Using my frist node"
  parllel_map = [
  'A': run_function("A")
  ]
}
parallel parllel_map