How to stop an unstoppable zombie job on Jenkins without restarting the server?

Question

Our Jenkins server has a job that has been running for three days, but is not doing anything. Clicking the little X in the corner does nothing, and the console output log do

Answer 1

Alexandru Bantiuc's answer worked well for me to stop the build, but my executors were still showing up as busy. I was able clear the busy executor status using the following

server_name_pattern = /your-servers-[1-5]/
jenkins.model.Jenkins.instance.getComputers().each { computer ->
  if (computer.getName().find(server_name_pattern)) {
    println computer.getName()
    execList = computer.getExecutors()      
    for( exec in execList ) {
      busyState = exec.isBusy() ? ' busy' : ' idle'
      println '--' + exec.getDisplayName() + busyState
      if (exec.isBusy()) {
        exec.interrupt()
      }
    }
  }
}