如何使用广播变量集成Spark Streaming和Kafka？

时间：2018-09-10 05:36:25

标签： scala apache-spark apache-kafka spark-streaming

在集成kafka和spark流时，广播变量有问题。当我不使用spark广播时，kafka和spark流集成没有问题，然后我使用广播，这是错误的。我将Spark Cluster作为独立服务器使用。我的scala代码是这样的，

object test {

  //spark streaming paramters
  var conf = new SparkConf().setAppName("SPK_test").setMaster("spark://192.168.90.21:7077")
  var sc = new SparkContext(conf)

  var ssc = new StreamingContext(sc, Seconds(30))
  //kafka
  val zkQuorum = "192.168.90.21:2181"
  val group = "GPS-group"
  val topicMap = "kl_ext_ms".split(":").map((_, 1)).toMap

  //broadcast public
  @volatile private var brcastMapTmp: Broadcast[Seq[((Int, Int, (Double, Double)), (Int, Int, (Double, Double)))]] = null

  def main(args: Array[String]): Unit = {

    //get data from mysql
    val wordBlacklist = getLineCoord()
    brcastMapTmp = sc.broadcast(wordBlacklist)

    //get data from kafka
    val waitDealDataFromJson = readFromKafka()
    //
    val result = waitDealDataFromJson.map(x => (isOnLineMin(x)))
    result.print()

    ssc.start()
    ssc.awaitTermination()
    ssc.stop()
  }


   def isOnLineMin(busRealPostion: (Int, Int, Double, (Double, Double))): ((Int, Int, (Double, Double)), (Int, Int, (Double, Double))) = {
    //this get error
    brcastMapTmp.value.toArray.foreach(x => print(x))

    val result =...
    result
  }
}

错误信息是这样的，

org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 4.0 failed 4 times, most recent failure: Lost task 0.3 in stage 4.0 (TID 86, slave1): java.io.IOException: org.apache.spark.SparkException: Failed to get broadcast_5_piece0 of broadcast_5
    at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1222)
    at org.apache.spark.broadcast.TorrentBroadcast.readBroadcastBlock(TorrentBroadcast.scala:165)
    at org.apache.spark.broadcast.TorrentBroadcast._value$lzycompute(TorrentBroadcast.scala:64)
    at org.apache.spark.broadcast.TorrentBroadcast._value(TorrentBroadcast.scala:64)
    at org.apache.spark.broadcast.TorrentBroadcast.getValue(TorrentBroadcast.scala:88)
    at org.apache.spark.broadcast.Broadcast.value(Broadcast.scala:70)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:62)
    at org.apache.spark.scheduler.Task.run(Task.scala:89)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.spark.SparkException: Failed to get broadcast_5_piece0 of broadcast_5
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1$$anonfun$2.apply(TorrentBroadcast.scala:138)
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1$$anonfun$2.apply(TorrentBroadcast.scala:138)
    at scala.Option.getOrElse(Option.scala:120)
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply$mcVI$sp(TorrentBroadcast.scala:137)
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply(TorrentBroadcast.scala:120)
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$org$apache$spark$broadcast$TorrentBroadcast$$readBlocks$1.apply(TorrentBroadcast.scala:120)
    at scala.collection.immutable.List.foreach(List.scala:318)
    at org.apache.spark.broadcast.TorrentBroadcast.org$apache$spark$broadcast$TorrentBroadcast$$readBlocks(TorrentBroadcast.scala:120)
    at org.apache.spark.broadcast.TorrentBroadcast$$anonfun$readBroadcastBlock$1.apply(TorrentBroadcast.scala:175)
    at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1219)
    ... 11 more

Driver stacktrace:
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1431)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1419)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1418)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1418)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:799)
    at scala.Option.foreach(Option.scala:236)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:799)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1640)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1599)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1588)
    at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:620)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1832)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1845)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1858)
    at org.apache.spark.rdd.RDD$$anonfun$take$1.apply(RDD.scala:1314)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:150)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:111)
    at org.apache.spark.rdd.RDD.withScope(RDD.scala:316)
    at org.apache.spark.rdd.RDD.take(RDD.scala:1288)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$print$2$$anonfun$foreachFunc$5$1.apply(DStream.scala:768)
    at org.apache.spark.streaming.dstream.DStream$$anonfun$print$2$$anonfun$foreachFunc$5$1.apply(DStream.scala:767)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply$mcV$sp(ForEachDStream.scala:50)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:50)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1$$anonfun$apply$mcV$sp$1.apply(ForEachDStream.scala:50)
    at org.apache.spark.streaming.dstream.DStream.createRDDWithLocalProperties(DStream.scala:426)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply$mcV$sp(ForEachDStream.scala:49)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:49)
    at org.apache.spark.streaming.dstream.ForEachDStream$$anonfun$1.apply(ForEachDStream.scala:49)
    at scala.util.Try$.apply(Try.scala:161)
    at org.apache.spark.streaming.scheduler.Job.run(Job.scala:39)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply$mcV$sp(JobScheduler.scala:224)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:224)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler$$anonfun$run$1.apply(JobScheduler.scala:224)
    at scala.util.DynamicVariable.withValue(DynamicVariable.scala:57)
    at org.apache.spark.streaming.scheduler.JobScheduler$JobHandler.run(JobScheduler.scala:223)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.IOException: org.apache.spark.SparkException: Failed to get broadcast_5_piece0 of broadcast_5
    at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1222)
    at org.apache.spark.broadcast.TorrentBroadcast.readBroadcastBlock(TorrentBroadcast.scala:165)
    at org.apache.spark.broadcast.TorrentBroadcast._value$lzycompute(TorrentBroadcast.scala:64)
    at org.apache.spark.broadcast.TorrentBroadcast._value(TorrentBroadcast.scala:64)
    at org.apache.spark.broadcast.TorrentBroadcast.getValue(TorrentBroadcast.scala:88)
    at org.apache.spark.broadcast.Broadcast.value(Broadcast.scala:70)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:62)
    at org.apache.spark.scheduler.Task.run(Task.scala:89)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
    ... 3 more

如何处理该错误？我使用的是Spark 1.6版

2 个答案:

答案 0 :(得分：0)

应在主方法内内定义主方法前的所有变量。

  • 然后，您将可以访问mysql，而无需使用var或将广播实例化为null。

答案 1 :(得分：0)

我知道为什么会有这个问题。broadcast变量用于在地图中使用的foreach RDD。我这样修改我的代码，

waitDealDataFromJson.foreachRDD(rdd => (isOnLineMinRDD(rdd))).

现在可以了。

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