Two questions, the answer to the general one will guide me on how minimal I can make a MVCE.
1) How can I know to register WrappedArray up front, (and every other class in Scala I might use)? Is it normal to have to register classes from libraries with Kryo?
and the specific:
2) How do I fix this? (Willing to admit I might have something else screwy going on that if reflecting a false error here, so don't kill yourselves trying to reproduce this)
DETAILS
Testing out a Spark program in Java using our customer classes related to genetics and statistic, on Spark 1.4.1, Scala 2.11.5 with the following settings on SparkConf:
// for kyro serializer it wants to register all classes that need to be serialized
Class[] kryoClassArray = new Class[]{DropResult.class, DropEvaluation.class, PrintHetSharing.class};
SparkConf sparkConf = new SparkConf().setAppName("PipeLinkageData")
<SNIP other settings to declare master>
.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
//require registration of all classes with Kryo
.set("spark.kryo.registrationRequired", "true")
.registerKryoClasses(kryoClassArray);
Getting this error (repeated at end of long error listing):
Caused by: java.lang.IllegalArgumentException: Class is not
registered: scala.collection.mutable.WrappedArray$ofRef Note: To
register this class use:
kryo.register(scala.collection.mutable.WrappedArray$ofRef.class);
But I never call that class from my code. I can add scala.collection.mutable.WrappedArray to the kryoClassArray but it doesn't fix the problem. If I add scala.collection.mutable.WrappedArray$ofRef.class (as suggested in the error) that's a syntax error, I see I can't declare an anonymous function here?
MVCE: I have started a MVCE but the problem is, to do one with our classes requires external libraries and text/data files. Once I strip out our classes, I don't have the problem. If someone could answer the general question it might help guide me on how much of an MVCE I can come up with.
As I am writing this question I got the go-ahead to update to 1.5.2, will see if there's any change there and update question if so.
Short of a MVCE here's my class declarations:
public class MVCEPipeLinkageInterface extends LinkageInterface implements Serializable {
class PrintHetSharing implements VoidFunction<DropResult> {
class SparkDoDrop implements Function<Integer, Integer> {
Full errors:
16/01/08 10:54:54 INFO TaskSchedulerImpl: Adding task set 0.0 with 2 tasks
16/01/08 10:54:55 INFO SparkDeploySchedulerBackend: Registered executor: AkkaRpcEndpointRef(Actor[akka.tcp://sparkExecutor@155.100.214.138:55646/user/Executor#214759698]) with ID 0
16/01/08 10:54:55 ERROR TaskSetManager: Failed to serialize task 0, not attempting to retry it.
java.io.IOException: java.lang.IllegalArgumentException: Class is not registered: scala.collection.mutable.WrappedArray$ofRef
Note: To register this class use: kryo.register(scala.collection.mutable.WrappedArray$ofRef.class);
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1242)
at org.apache.spark.rdd.ParallelCollectionPartition.writeObject(ParallelCollectionRDD.scala:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at org.apache.spark.serializer.JavaSerializationStream.writeObject(JavaSerializer.scala:44)
at org.apache.spark.serializer.JavaSerializerInstance.serialize(JavaSerializer.scala:81)
at org.apache.spark.scheduler.Task$.serializeWithDependencies(Task.scala:168)
at org.apache.spark.scheduler.TaskSetManager.resourceOffer(TaskSetManager.scala:467)
at org.apache.spark.scheduler.TaskSchedulerImpl$$anonfun$org$apache$spark$scheduler$TaskSchedulerImpl$$resourceOfferSingleTaskSet$1.apply$mcVI$sp(TaskSchedulerImpl.scala:231)
at scala.collection.immutable.Range.foreach$mVc$sp(Range.scala:141)
at org.apache.spark.scheduler.TaskSchedulerImpl.org$apache$spark$scheduler$TaskSchedulerImpl$$resourceOfferSingleTaskSet(TaskSchedulerImpl.scala:226)
at org.apache.spark.scheduler.TaskSchedulerImpl$$anonfun$resourceOffers$3$$anonfun$apply$6.apply(TaskSchedulerImpl.scala:295)
at org.apache.spark.scheduler.TaskSchedulerImpl$$anonfun$resourceOffers$3$$anonfun$apply$6.apply(TaskSchedulerImpl.scala:293)
at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:108)
at org.apache.spark.scheduler.TaskSchedulerImpl$$anonfun$resourceOffers$3.apply(TaskSchedulerImpl.scala:293)
at org.apache.spark.scheduler.TaskSchedulerImpl$$anonfun$resourceOffers$3.apply(TaskSchedulerImpl.scala:293)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
at org.apache.spark.scheduler.TaskSchedulerImpl.resourceOffers(TaskSchedulerImpl.scala:293)
at org.apache.spark.scheduler.cluster.CoarseGrainedSchedulerBackend$DriverEndpoint.makeOffers(CoarseGrainedSchedulerBackend.scala:167)
at org.apache.spark.scheduler.cluster.CoarseGrainedSchedulerBackend$DriverEndpoint$$anonfun$receiveAndReply$1.applyOrElse(CoarseGrainedSchedulerBackend.scala:143)
at org.apache.spark.rpc.akka.AkkaRpcEnv.org$apache$spark$rpc$akka$AkkaRpcEnv$$processMessage(AkkaRpcEnv.scala:178)
at org.apache.spark.rpc.akka.AkkaRpcEnv$$anonfun$actorRef$lzycompute$1$1$$anon$1$$anonfun$receiveWithLogging$1$$anonfun$applyOrElse$4.apply$mcV$sp(AkkaRpcEnv.scala:127)
at org.apache.spark.rpc.akka.AkkaRpcEnv.org$apache$spark$rpc$akka$AkkaRpcEnv$$safelyCall(AkkaRpcEnv.scala:198)
at org.apache.spark.rpc.akka.AkkaRpcEnv$$anonfun$actorRef$lzycompute$1$1$$anon$1$$anonfun$receiveWithLogging$1.applyOrElse(AkkaRpcEnv.scala:126)
at scala.runtime.AbstractPartialFunction$mcVL$sp.apply$mcVL$sp(AbstractPartialFunction.scala:33)
at scala.runtime.AbstractPartialFunction$mcVL$sp.apply(AbstractPartialFunction.scala:33)
at scala.runtime.AbstractPartialFunction$mcVL$sp.apply(AbstractPartialFunction.scala:25)
at org.apache.spark.util.ActorLogReceive$$anon$1.apply(ActorLogReceive.scala:59)
at org.apache.spark.util.ActorLogReceive$$anon$1.apply(ActorLogReceive.scala:42)
at scala.PartialFunction$class.applyOrElse(PartialFunction.scala:118)
at org.apache.spark.util.ActorLogReceive$$anon$1.applyOrElse(ActorLogReceive.scala:42)
at akka.actor.Actor$class.aroundReceive(Actor.scala:465)
at org.apache.spark.rpc.akka.AkkaRpcEnv$$anonfun$actorRef$lzycompute$1$1$$anon$1.aroundReceive(AkkaRpcEnv.scala:93)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)
at akka.actor.ActorCell.invoke(ActorCell.scala:487)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238)
at akka.dispatch.Mailbox.run(Mailbox.scala:220)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.lang.IllegalArgumentException: Class is not registered: scala.collection.mutable.WrappedArray$ofRef
Note: To register this class use: kryo.register(scala.collection.mutable.WrappedArray$ofRef.class);
In Scala you should fix this issue adding 'scala.collection.mutable.WrappedArray.ofRef[_]' as registered class as in the following snippet:
conf.registerKryoClasses(
Array(
...
classOf[Person],
classOf[Array[Person]],
...
classOf[scala.collection.mutable.WrappedArray.ofRef[_]]
)
)