Differenza di scintilla tra gli artefatti di carattere spark-core_2.10 e spark-core_2.11

Question

Qualcuno conosce la differenza tra i due artefatti della scintilla? Entrambi supportano Spark fino alla versione 1.5.1. Tuttavia, alawys finisco con lo stesso errore quando uso spark-core_2.11 nella mia applicazione Java e cerco di connettermi al cluster standalone (Spark-1.5.1) con l'URL spark (spark: // masterIP: Port)

WARN ReliableDeliverySupervisor: Association with remote system [akka.tcp://sparkMaster@192.168.188.20:7077] has failed, address is now gated for [5000] ms. Reason: [Disassociated] 
ERROR SparkUncaughtExceptionHandler: Uncaught exception in thread Thread[appclient-registration-retry-thread,5,main] 

Il master registra anche un problema compability nei suoi ceppi:

ERROR Remoting: org.apache.spark.deploy.DeployMessages$RegisterApplication; local class incompatible: stream classdesc serialVersionUID = 352674063933172066, local class serialVersionUID = -5495080032843259921 
java.io.InvalidClassException: org.apache.spark.deploy.DeployMessages$RegisterApplication; local class incompatible: stream classdesc serialVersionUID = 352674063933172066, local class serialVersionUID = -5495080032843259921 
    at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:621) 
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1623) 
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1518) 
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1774) 
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351) 
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371) 
    at akka.serialization.JavaSerializer$$anonfun$1.apply(Serializer.scala:136) 
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57) 
    at akka.serialization.JavaSerializer.fromBinary(Serializer.scala:136) 
    at akka.serialization.Serialization$$anonfun$deserialize$1.apply(Serialization.scala:104) 
    at scala.util.Try$.apply(Try.scala:161) 
    at akka.serialization.Serialization.deserialize(Serialization.scala:98) 
    at akka.remote.serialization.MessageContainerSerializer.fromBinary(MessageContainerSerializer.scala:63) 
    at akka.serialization.Serialization$$anonfun$deserialize$1.apply(Serialization.scala:104) 
    at scala.util.Try$.apply(Try.scala:161) 
    at akka.serialization.Serialization.deserialize(Serialization.scala:98) 
    at akka.remote.MessageSerializer$.deserialize(MessageSerializer.scala:23) 
    at akka.remote.DefaultMessageDispatcher.payload$lzycompute$1(Endpoint.scala:58) 
    at akka.remote.DefaultMessageDispatcher.payload$1(Endpoint.scala:58) 
    at akka.remote.DefaultMessageDispatcher.dispatch(Endpoint.scala:76) 
    at akka.remote.EndpointReader$$anonfun$receive$2.applyOrElse(Endpoint.scala:935) 
    at akka.actor.Actor$class.aroundReceive(Actor.scala:467) 
    at akka.remote.EndpointActor.aroundReceive(Endpoint.scala:411) 
    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$AkkaForkJoinTask.exec(AbstractDispatcher.scala:397) 
    at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) 
    at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) 
    at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) 
    at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107) 

Quando si utilizza scintilla core_2.10 tutto funziona bene.

Answer 1

Questi errori sono dovuti a una mancata corrispondenza con la versione scala.

Spark è compilato sia per scala 2.10.x che per Spark 2.11.x, se si desidera utilizzare Scala 2.10 e, naturalmente, se è installato nell'env, sarà necessario spark-core_2.10 e spark-core_2.11 per Scala 2.11.

PS: A un certo punto, credo che fosse disponibile per Scala 2.9