相关疑难解决方法(0)

这个错误是最难追查的.我不确定发生了什么.我正在我的位置机器上运行Spark集群.所以整个火花集群都在一个主机下127.0.0.1,我在独立模式下运行

JavaPairRDD<byte[], Iterable<CassandraRow>> cassandraRowsRDD= javaFunctions(sc).cassandraTable("test", "hello" )
   .select("rowkey", "col1", "col2", "col3",  )
   .spanBy(new Function<CassandraRow, byte[]>() {
        @Override
        public byte[] call(CassandraRow v1) {
            return v1.getBytes("rowkey").array();
        }
    }, byte[].class);

Iterable<Tuple2<byte[], Iterable<CassandraRow>>> listOftuples = cassandraRowsRDD.collect(); //ERROR HAPPENS HERE
Tuple2<byte[], Iterable<CassandraRow>> tuple = listOftuples.iterator().next();
byte[] partitionKey = tuple._1();
for(CassandraRow cassandraRow: tuple._2()) {
    System.out.println("************START************");
    System.out.println(new String(partitionKey));
    System.out.println("************END************");
}

这个错误是最难追查的.它显然发生在cassandraRowsRDD.collect(),我不知道为什么？

16/10/09 23:36:21 ERROR Executor: Exception in task 2.3 in stage 0.0 (TID 21)
java.lang.ClassCastException: cannot assign instance of scala.collection.immutable.List$SerializationProxy to field org.apache.spark.rdd.RDD.org$apache$spark$rdd$RDD$$dependencies_ …