Program: 87071
Project: 87071
Buggy source:
private void initializeDataClient(){
  LOG.debug("String_Node_Str");
  dataWorkerGroup=new NioEventLoopGroup(DATA_WORKER_THREADS);
  Bootstrap b=new Bootstrap();
  b.group(dataWorkerGroup).channelFactory(new ChannelFactory<Channel>(){
    @Override public Channel newChannel(){
      return new NioDatagramChannel(InternetProtocolFamily.IPv4);
    }
    @Override public String toString(){
      return NioDatagramChannel.class.getSimpleName() + "String_Node_Str";
    }
  }
).handler(new ChannelInitializer<DatagramChannel>(){
    @Override public void initChannel(    DatagramChannel ch) throws Exception {
      ch.pipeline().addLast("String_Node_Str",new ByteArrayEncoder());
      ch.pipeline().addLast("String_Node_Str",new ByteArrayDecoder());
      ch.pipeline().addLast(new DataExceptionHandler());
      if (LOG.isTraceEnabled()) {
        ch.pipeline().addLast(new LoggingHandler(LogLevel.TRACE));
      }
    }
    @Override public void exceptionCaught(    ChannelHandlerContext ctx,    Throwable cause) throws Exception {
      LOG.error("String_Node_Str",cause);
      ctx.close();
    }
  }
);
  ChannelFuture future=b.connect(getIp(),getDataPort()).awaitUninterruptibly();
  if (future.isCancelled()) {
    dataChannel=null;
  }
 else   if (!future.isSuccess()) {
    dataChannel=null;
    retryDataConnection();
  }
 else {
    dataChannel=(DatagramChannel)future.channel();
    try {
      dataChannel.closeFuture().sync();
    }
 catch (    InterruptedException ex) {
      LOG.warn("String_Node_Str",ex);
    }
  }
}

Fixed version (ground truth):
private void initializeDataClient(){
  LOG.trace("String_Node_Str");
  dataWorkerGroup=new NioEventLoopGroup(DATA_WORKER_THREADS);
  Bootstrap b=new Bootstrap();
  b.group(dataWorkerGroup).channelFactory(new ChannelFactory<Channel>(){
    @Override public Channel newChannel(){
      return new NioDatagramChannel(InternetProtocolFamily.IPv4);
    }
    @Override public String toString(){
      return NioDatagramChannel.class.getSimpleName() + "String_Node_Str";
    }
  }
).handler(new ChannelInitializer<DatagramChannel>(){
    @Override public void initChannel(    DatagramChannel ch) throws Exception {
      ch.config().setAllocator(UnpooledByteBufAllocator.DEFAULT);
      ch.pipeline().addLast("String_Node_Str",new ByteArrayEncoder());
      ch.pipeline().addLast("String_Node_Str",new ByteArrayDecoder());
      ch.pipeline().addLast(new DataExceptionHandler());
      if (LOG.isTraceEnabled()) {
        ch.pipeline().addLast(new LoggingHandler(LogLevel.TRACE));
      }
    }
    @Override public void exceptionCaught(    ChannelHandlerContext ctx,    Throwable cause) throws Exception {
      LOG.error("String_Node_Str",cause);
      ctx.close();
    }
  }
);
  ChannelFuture future=b.connect(getIp(),getDataPort()).awaitUninterruptibly();
  if (future.isCancelled()) {
    dataChannel=null;
  }
 else   if (!future.isSuccess()) {
    dataChannel=null;
    retryDataConnection();
  }
 else {
    dataChannel=(DatagramChannel)future.channel();
    try {
      dataChannel.closeFuture().sync();
    }
 catch (    InterruptedException ex) {
      LOG.warn("String_Node_Str",ex);
    }
  }
}