For me, PageRank fails when I use Kryo (works fine if I don't). I found the same problem reported here: https://groups.google.com/forum/#!topic/spark-users/unngi3JdRk8 .
Has this been resolved? I'm not launching code from spark-shell. I tried registering GraphKryoRegistrator (instead of my own classes), I still get the below error: 2014-04-23 15:17:35 ERROR OneForOneStrategy:66 - scala.collection.immutable.$colon$colon cannot be cast to org.apache.spark.util.BoundedPriorityQueue java.lang.ClassCastException: scala.collection.immutable.$colon$colon cannot be cast to org.apache.spark.util.BoundedPriorityQueue at org.apache.spark.rdd.RDD$$anonfun$top$2.apply(RDD.scala:879) at org.apache.spark.rdd.RDD$$anonfun$6.apply(RDD.scala:677) at org.apache.spark.rdd.RDD$$anonfun$6.apply(RDD.scala:674) at org.apache.spark.scheduler.JobWaiter.taskSucceeded(JobWaiter.scala:56) at org.apache.spark.scheduler.DAGScheduler.handleTaskCompletion(DAGScheduler.scala:846) at org.apache.spark.scheduler.DAGScheduler.processEvent(DAGScheduler.scala:601) at org.apache.spark.scheduler.DAGScheduler$$anonfun$start$1$$anon$2$$anonfun$receive$1.applyOrElse(DAGScheduler.scala:190) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498) at akka.actor.ActorCell.invoke(ActorCell.scala:456) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237) at akka.dispatch.Mailbox.run(Mailbox.scala:219) at akka.dispatch.ForkJoinExecutorConfigurator$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)
