public void setHostRoleStatus(String hostname, String role,
      HostRoleStatus status) {
    hostRoleCommands.get(getSafeHost(hostname)).get(role).setStatus(status);
  }
@param hostname    the hostname; {@code null} for a server-side stage
@param role        the role
@param status      the status
ambari-server/src/main/java/org/apache/ambari/server/actionmanager/Stage.java