Spark进程无法在yarn-client模式下从Kafka队列接收数据

Question

我正在尝试使用yarn-client模式运行以下代码，但是下面提到的读取处理器错误很慢，但代码在本地模式下运行正常。任何指针都非常感激。

从Kafka Queue接收数据的代码行：

using System.Net;
using System.IO;

String[] URLList = File.ReadAllLines(C:\yourURLFile.txt");

foreach (String URL in URLList) {
    using (WebClient webClient = new WebClient()) {
         webClient.DownloadFileAsync(new Uri(URL), @"C:\PicFolder\"); 
    }
}

错误详情：

JavaPairReceiverInputDStream<String, String> messages =  KafkaUtils.createStream(jssc, String.class, String.class, StringDecoder.class, StringDecoder.class, kafkaParams, kafkaTopicMap, StorageLevel.MEMORY_ONLY());

JavaDStream<String> lines = messages.map(new Function<Tuple2<String, String>, String>() {
      public String call(Tuple2<String, String> tuple2) {
                              LOG.info(" &&&&&&&&&&&&&&&&&&&& Input json stream data  " +  tuple2._2);
        return tuple2._2();
      }
    });