Spark中使用UDF遇到的一个奇怪的问题 2015-01-19 12:00:13 代码没有任何问题，注册UDF也没有任何问题，使用方法也没有错误，运行时出现以下错误： ``` org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 0.0 failed 1 times, most recent failure: Lost task 0.0 in stage 0.0 (TID 0, localhost): java.lang.reflect.InvocationTargetException: sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) java.lang.reflect.Method.invoke(Method.java:606) org.apache.spark.sql.hive.HiveSimpleUdf.eval(hiveUdfs.scala:152) org.apache.spark.sql.catalyst.expressions.Alias.eval(namedExpressions.scala:84) org.apache.spark.sql.catalyst.expressions.InterpretedMutableProjection.apply(Projection.scala:66) org.apache.spark.sql.catalyst.expressions.InterpretedMutableProjection.apply(Projection.scala:50) scala.collection.Iterator$$anon$11.next(Iterator.scala:328) scala.collection.Iterator$$anon$11.next(Iterator.scala:328) scala.collection.Iterator$class.foreach(Iterator.scala:727) scala.collection.AbstractIterator.foreach(Iterator.scala:1157) scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:48) scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:103) scala.collection.mutable.ArrayBuffer.$plus$plus$eq(ArrayBuffer.scala:47) scala.collection.TraversableOnce$class.to(TraversableOnce.scala:273) scala.collection.AbstractIterator.to(Iterator.scala:1157) scala.collection.TraversableOnce$class.toBuffer(TraversableOnce.scala:265) scala.collection.AbstractIterator.toBuffer(Iterator.scala:1157) scala.collection.TraversableOnce$class.toArray(TraversableOnce.scala:252) scala.collection.AbstractIterator.toArray(Iterator.scala:1157) org.apache.spark.rdd.RDD$$anonfun$16.apply(RDD.scala:774) org.apache.spark.rdd.RDD$$anonfun$16.apply(RDD.scala:774) org.apache.spark.SparkContext$$anonfun$runJob$4.apply(SparkContext.scala:1143) org.apache.spark.SparkContext$$anonfun$runJob$4.apply(SparkContext.scala:1143) org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:62) org.apache.spark.scheduler.Task.run(Task.scala:54) org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:178) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) java.lang.Thread.run(Thread.java:745) Driver stacktrace: at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1185) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1174) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1173) at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1173) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:688) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:688) at scala.Option.foreach(Option.scala:236) at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:688) at org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1391) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498) at akka.actor.ActorCell.invoke(ActorCell.scala:456) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237) at akka.dispatch.Mailbox.run(Mailbox.scala:219) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) ``` 最终排查的原因为，udf所在的jar包种有个类，和classpath中的某个jar的类完全重名了，刚好自定义的UDF用到了这个类，java从旧的重名类中通过反射查找用到的方法，找不到，就出错了。 解决方法：改一下类名或包名，保证命名不冲突就可以了。 非特殊说明，均为原创，原创文章，未经允许谢绝转载。 原始链接：Spark中使用UDF遇到的一个奇怪的问题 赏 Prev Python为什么需要reload(sys)后在设置默认编码 Next Spark Application日志输出的问题
