Spark 2.0.0 SPARK-SQL returns NPE Error

com.esotericsoftware.kryo.KryoException: java.lang.NullPointerException
Serialization trace:
underlying (org.apache.spark.util.BoundedPriorityQueue)
    at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:144)
    at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:551)
    at com.esotericsoftware.kryo.Kryo.readClassAndObject(Kryo.java:793)
    at com.twitter.chill.SomeSerializer.read(SomeSerializer.scala:25)
    at com.twitter.chill.SomeSerializer.read(SomeSerializer.scala:19)
    at com.esotericsoftware.kryo.Kryo.readClassAndObject(Kryo.java:793)
    at org.apache.spark.serializer.KryoSerializerInstance.deserialize(KryoSerializer.scala:312)
    at org.apache.spark.scheduler.DirectTaskResult.value(TaskResult.scala:87)
    at org.apache.spark.scheduler.TaskResultGetter$$anon$2$$anonfun$run$1.apply$mcV$sp(TaskResultGetter.scala:66)
    at org.apache.spark.scheduler.TaskResultGetter$$anon$2$$anonfun$run$1.apply(TaskResultGetter.scala:57)
    at org.apache.spark.scheduler.TaskResultGetter$$anon$2$$anonfun$run$1.apply(TaskResultGetter.scala:57)
    at org.apache.spark.util.Utils$.logUncaughtExceptions(Utils.scala:1793)
    at org.apache.spark.scheduler.TaskResultGetter$$anon$2.run(TaskResultGetter.scala:56)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at org.apache.spark.sql.catalyst.expressions.codegen.LazilyGeneratedOrdering.compare(GenerateOrdering.scala:157)
    at org.apache.spark.sql.catalyst.expressions.codegen.LazilyGeneratedOrdering.compare(GenerateOrdering.scala:148)
    at scala.math.Ordering$$anon$4.compare(Ordering.scala:111)
    at java.util.PriorityQueue.siftUpUsingComparator(PriorityQueue.java:669)
    at java.util.PriorityQueue.siftUp(PriorityQueue.java:645)
    at java.util.PriorityQueue.offer(PriorityQueue.java:344)
    at java.util.PriorityQueue.add(PriorityQueue.java:321)
    at com.twitter.chill.java.PriorityQueueSerializer.read(PriorityQueueSerializer.java:78)
    at com.twitter.chill.java.PriorityQueueSerializer.read(PriorityQueueSerializer.java:31)
    at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:711)
    at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:125)
    ... 15 more
16/05/24 09:42:53 ERROR SparkSQLDriver: Failed in [     select
             dt.d_year
            ,item.i_brand_id brand_id
            ,item.i_brand brand
            ,sum(ss_ext_sales_price) sum_agg
     from  date_dim dt
          ,store_sales
          ,item
     where dt.d_date_sk = store_sales.ss_sold_date_sk
       and store_sales.ss_item_sk = item.i_item_sk
       and item.i_manufact_id = 436
       and dt.d_moy=12
     group by dt.d_year
          ,item.i_brand
          ,item.i_brand_id
     order by dt.d_year
             ,sum_agg desc
             ,brand_id
     limit 100]

　　莫名其妙的出现空指针异常～后来在网上发现其他人的类似情况：

When kryo serialization is used, the query fails when ORDER BY and LIMIT is combined. After removing either ORDER BY or LIMIT clause, the query also runs.

查了一下，发现是spark 2.0.0对kryo序列化的依赖有bug，到SPARK_HOME/conf/spark-defaults.conf

默认为 ：

# spark.serializer                 org.apache.spark.serializer.KryoSerializer

改成：

spark.serializer org.apache.spark.serializer.JavaSerializer