I’m running this query against RDD[Tweet], where Tweet is a simple case class with 4 fields.
sqlContext.sql(""" SELECT user, COUNT(*) as num_tweets FROM tweets GROUP BY user ORDER BY num_tweets DESC, user ASC ; """).take(5) The first time I run this, it throws the following: 14/07/15 06:11:51 ERROR TaskSetManager: Task 12.0:0 failed 4 times; aborting job org.apache.spark.SparkException: Job aborted due to stage failure: Task 12.0:0 failed 4 times, most recent failure: Exception failure in TID 978 on host ip-10-144-204-254.ec2.internal: java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.String scala.math.Ordering$String$.compare(Ordering.scala:329) org.apache.spark.sql.catalyst.expressions.RowOrdering.compare(Row.scala:227) org.apache.spark.sql.catalyst.expressions.RowOrdering.compare(Row.scala:210) java.util.TimSort.mergeLo(TimSort.java:687) java.util.TimSort.mergeAt(TimSort.java:483) java.util.TimSort.mergeCollapse(TimSort.java:410) java.util.TimSort.sort(TimSort.java:214) java.util.TimSort.sort(TimSort.java:173) java.util.Arrays.sort(Arrays.java:659) scala.collection.SeqLike$class.sorted(SeqLike.scala:615) scala.collection.mutable.ArrayOps$ofRef.sorted(ArrayOps.scala:108) org.apache.spark.sql.execution.Sort$$anonfun$execute$3$$anonfun$apply$4.apply(basicOperators.scala:154) org.apache.spark.sql.execution.Sort$$anonfun$execute$3$$anonfun$apply$4.apply(basicOperators.scala:154) org.apache.spark.rdd.RDD$$anonfun$12.apply(RDD.scala:559) org.apache.spark.rdd.RDD$$anonfun$12.apply(RDD.scala:559) org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35) org.apache.spark.sql.SchemaRDD.compute(SchemaRDD.scala:110) org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:262) org.apache.spark.rdd.RDD.iterator(RDD.scala:229) org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:111) org.apache.spark.scheduler.Task.run(Task.scala:51) org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:187) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) java.lang.Thread.run(Thread.java:744) Driver stacktrace: at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1033) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1017) at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1015) at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59) at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47) at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1015) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:633) at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:633) at scala.Option.foreach(Option.scala:236) at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:633) at org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1207) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498) at akka.actor.ActorCell.invoke(ActorCell.scala:456) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237) at akka.dispatch.Mailbox.run(Mailbox.scala:219) at akka.dispatch.ForkJoinExecutorConfigurator$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) If I immediately re-run the query, it works fine. I’ve been able to reproduce this a few times. If I run other, simpler SELECT queries first and then this one, it also gets around the problem. Strange… I’m on 1.0.0 on EC2. Nick -- View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/Spark-SQL-throws-ClassCastException-on-first-try-works-on-second-tp9720.html Sent from the Apache Spark User List mailing list archive at Nabble.com.