@Override public void doNotify() throws Exception {
  log.info("Received notification that related system properties are changed");
  ScheduledExecutorService svc=service;
  if (svc != null) {
    try {
      svc.schedule((Callable<Object>)this,0L,TimeUnit.MICROSECONDS);
    }
 catch (    RejectedExecutionException ex) {
      if (svc.isShutdown()) {
        log.info("Property change notification ignored because this node is no longer backup leader.");
      }
 else {
        throw ex;
      }
    }
  }
 else {
    log.info("Property change notification ignored because this node is no longer backup leader.");
  }
}

@ Override public void doNotify ( ) throws Exception { log . info ( "Received notification that related system properties are changed" ) ; ScheduledExecutorService svc = service ; if ( svc != null ) { try { svc . schedule ( ( Callable < Object > ) this , 0L , TimeUnit . MICROSECONDS ) ; } catch ( RejectedExecutionException ex ) { if ( svc . isShutdown ( ) ) { log . info ( "Property change notification ignored because this node is no longer backup leader." ) ; } else { throw ex ; } } } else { log . info ( "Property change notification ignored because this node is no longer backup leader." ) ; } }
called when related system properties are changed , and we need to reschedule
