apache-spark - 写语句失败

Question

我将 spark 与 cassandra 一起使用，我想将数据写入我的 cassandra 表:

CREATE TABLE IF NOT EXISTS MyTable(
 user TEXT,
 date TIMESTAMP,
 event TEXT,
 PRIMARY KEY((user ),date , event)
);

但是我得到了这个错误:

java.io.IOException: Failed to write statements to KeySpace.MyTable.
    at    com.datastax.spark.connector.writer.TableWriter$$anonfun$write$1.apply(TableWriter.scala:145)
    at com.datastax.spark.connector.writer.TableWriter$$anonfun$write$1.apply(TableWriter.scala:120)
    at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$withSessionDo$1.apply(CassandraConnector.scala:100)
    at com.datastax.spark.connector.cql.CassandraConnector$$anonfun$withSessionDo$1.apply(CassandraConnector.scala:99)
    at com.datastax.spark.connector.cql.CassandraConnector.closeResourceAfterUse(CassandraConnector.scala:151)
    at com.datastax.spark.connector.cql.CassandraConnector.withSessionDo(CassandraConnector.scala:99)
    at com.datastax.spark.connector.writer.TableWriter.write(TableWriter.scala:120)
    at com.datastax.spark.connector.RDDFunctions$$anonfun$saveToCassandra$1.apply(RDDFunctions.scala:36)
    at com.datastax.spark.connector.RDDFunctions$$anonfun$saveToCassandra$1.apply(RDDFunctions.scala:36)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:61)
    at org.apache.spark.scheduler.Task.run(Task.scala:56)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:200)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    Driver stacktrace:
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1214)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1203)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1202)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1202)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:696)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:696)
    at scala.Option.foreach(Option.scala:236)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:696)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessActor$$anonfun$receive$2.applyOrElse(DAGScheduler.scala:1420)
    at akka.actor.Actor$class.aroundReceive(Actor.scala:465)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessActor.aroundReceive(DAGScheduler.scala:1375)
    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)
15/04/28 17:57:47 WARN TaskSetManager: Lost task 13.2 in stage 1.0 (TID 43, dev2-cim.aid.fr): TaskKilled (killed intentionally)

以及我的 Cassandra 日志文件中的警告:

WARN  [SharedPool-Worker-2] 2015-04-28 16:45:21,219 BatchStatement.java:243 - Batch of prepared statements for [*********] is of size 8158, exceeding specified threshold of 5120 by 3038

在互联网上进行一些搜索后，我找到了这个链接，他解释了他如何解决同样的问题: http://progexc.blogspot.fr/2015/03/write-batch-size-error-spark-cassandra.html

所以，现在我修改了我的 spark 算法以添加:

conf.set("spark.cassandra.output.batch.grouping.key", "None")
conf.set("spark.cassandra.output.batch.size.rows", "10")
conf.set("spark.cassandra.output.batch.size.bytes", "2048")

这个值删除了我在 cassandra 日志中收到的警告消息，但我仍然有同样的错误:Failed to write statements。

在我的 spark 日志中，我发现了这个错误:

Failed to execute: 
    com.datastax.spark.connector.writer.RichBatchStatement@67827d57
    com.datastax.driver.core.exceptions.InvalidQueryException: Key may not be    empty
    at com.datastax.driver.core.Responses$Error.asException(Responses.java:103)
    at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:140)
    at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:293)
    at com.datastax.driver.core.RequestHandler.onSet(RequestHandler.java:455)
    at com.datastax.driver.core.Connection$Dispatcher.messageReceived(Connection.java:734)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.handler.timeout.IdleStateAwareChannelUpstreamHandler.handleUpstream(IdleStateAwareChannelUpstreamHandler.java:36)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.handler.timeout.IdleStateHandler.messageReceived(IdleStateHandler.java:294)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296)
    at org.jboss.netty.handler.codec.oneone.OneToOneDecoder.handleUpstream(OneToOneDecoder.java:70)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessageReceived(FrameDecoder.java:462)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:443)
    at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:303)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70)
    at  org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:268)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:255)
    at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:88)

Answer 1

我遇到了同样的问题，并在上​​面的评论中找到了解决方案(Amine CHERIFI 和 maasg)。

与主键对应的列并不总是用正确的值填充(在我的例子中是一个空字符串“”)。

这触发了错误

ERROR QueryExecutor: Failed to execute: \
com.datastax.spark.connector.writer.RichBatchStatement@26ad2668 \
com.datastax.driver.core.exceptions.InvalidQueryException: Key may not be empty

解决方案是提供一个默认的非空字符串。