运行 spark-submit 作业并收到“无法获取 broadcast_58_piece0...”错误。我真的不确定我做错了什么。我是否过度使用了 UDF？功能太复杂？

作为我的目标的总结，我正在解析 pdf 中的文本，这些文本作为 base64 编码的字符串存储在 JSON 对象中。我正在使用 Apache Tika 获取文本，并尝试大量使用数据帧来简化操作。

我写了一段代码，通过 tika 将文本提取作为“主”之外的一个函数在数据上作为 RDD 运行，并且运行完美。但是，当我尝试将提取作为数据帧上的 UDF 引入 main 时，它会以各种不同的方式出现问题。在我到达这里之前，我实际上是在尝试将最终数据框编写为:

valid.toJSON.saveAsTextFile(hdfs_dir)

这让我对“文件/路径已经存在”感到头疼。

当前代码:

object Driver {

  def main(args: Array[String]):Unit = {
    val hdfs_dir = args(0)
    val spark_conf = new SparkConf().setAppName("Spark Tika HDFS")
    val sc = new SparkContext(spark_conf)
    val sqlContext = new org.apache.spark.sql.SQLContext(sc)

    import sqlContext.implicits._

    // load json data into dataframe
    val df = sqlContext.read.json("hdfs://hadoophost.com:8888/user/spark/data/in/*")

    val extractInfo: (Array[Byte] => String) = (fp: Array[Byte]) => {

      val parser:Parser = new AutoDetectParser()
      val handler:BodyContentHandler = new BodyContentHandler(Integer.MAX_VALUE)
      val config:TesseractOCRConfig  = new TesseractOCRConfig()
      val pdfConfig:PDFParserConfig = new PDFParserConfig()

      val inputstream:InputStream = new ByteArrayInputStream(fp)

      val metadata:Metadata = new  Metadata()
      val parseContext:ParseContext = new ParseContext()
      parseContext.set(classOf[TesseractOCRConfig], config)
      parseContext.set(classOf[PDFParserConfig], pdfConfig)
      parseContext.set(classOf[Parser], parser)
      parser.parse(inputstream, handler, metadata, parseContext)
      handler.toString
    }


    val extract_udf = udf(extractInfo)

    val df2 = df.withColumn("unbased_media", unbase64($"media_file")).drop("media_file")

    val dfRenamed = df2.withColumn("media_corpus", extract_udf(col("unbased_media"))).drop("unbased_media")

    val depuncter: (String => String) = (corpus: String) => {
        val r = corpus.replaceAll("""[\p{Punct}]""", "")
        val s = r.replaceAll("""[0-9]""", "")
        s
    }

    val depuncter_udf = udf(depuncter)

    val withoutPunct = dfRenamed.withColumn("sentence", depuncter_udf(col("media_corpus")))

    val model = sc.objectFile[org.apache.spark.ml.PipelineModel]("hdfs://hadoophost.com:8888/user/spark/hawkeye-nb-ml-v2.0").first()

    val with_predictions = model.transform(withoutPunct)

    val fullNameChecker: ((String, String, String, String, String) => String) = (fname: String, mname: String, lname: String, sfx: String, text: String) =>{
        val newtext = text.replaceAll(" ", "").replaceAll("""[0-9]""", "").replaceAll("""[\p{Punct}]""", "").toLowerCase
        val new_fname = fname.replaceAll(" ", "").replaceAll("""[0-9]""", "").replaceAll("""[\p{Punct}]""", "").toLowerCase
        val new_mname = mname.replaceAll(" ", "").replaceAll("""[0-9]""", "").replaceAll("""[\p{Punct}]""", "").toLowerCase
        val new_lname = lname.replaceAll(" ", "").replaceAll("""[0-9]""", "").replaceAll("""[\p{Punct}]""", "").toLowerCase
        val new_sfx = sfx.replaceAll(" ", "").replaceAll("""[0-9]""", "").replaceAll("""[\p{Punct}]""", "").toLowerCase
        val name_full = new_fname.concat(new_mname).concat(new_lname).concat(new_sfx)
        val c = name_full.r.findAllIn(newtext).length
        c match {
            case 0 => "N"
            case _ => "Y"
        }
    }

    val fullNameChecker_udf = udf(fullNameChecker)

    val stringChecker: ((String, String) => String) = (term: String, text: String) => {
        val termLower = term.replaceAll("""[\p{Punct}]""", "").toLowerCase
        val textLower = text.replaceAll("""[\p{Punct}]""", "").toLowerCase
        val c = termLower.r.findAllIn(textLower).length
        c match {
        case 0 => "N"
        case _ => "Y"
        }
    }

    val stringChecker_udf = udf(stringChecker)


    val stringChecker2: ((String, String) => String) = (term: String, text: String) => {
        val termLower = term takeRight 4
        val textLower = text
        val c = termLower.r.findAllIn(textLower).length
        c match {
        case 0 => "N"
        case _ => "Y"
        }
    }

    val stringChecker2_udf = udf(stringChecker)

    val valids = with_predictions.withColumn("fname_valid", stringChecker_udf(col("first_name"), col("media_corpus")))
                                            .withColumn("lname_valid", stringChecker_udf(col("last_name"), col("media_corpus")))
                                            .withColumn("fname2_valid", stringChecker_udf(col("first_name_2"), col("media_corpus")))
                                            .withColumn("lname2_valid", stringChecker_udf(col("last_name_2"), col("media_corpus")))
                                            .withColumn("camt_valid", stringChecker_udf(col("chargeoff_amount"), col("media_corpus")))
                                            .withColumn("ocan_valid", stringChecker2_udf(col("original_creditor_account_nbr"), col("media_corpus")))
                                            .withColumn("dpan_valid", stringChecker2_udf(col("debt_provider_account_nbr"), col("media_corpus")))
                                            .withColumn("full_name_valid", fullNameChecker_udf(col("first_name"), col("middle_name"), col("last_name"), col("suffix"), col("media_corpus")))
                                            .withColumn("full_name_2_valid", fullNameChecker_udf(col("first_name_2"), col("middle_name_2"), col("last_name_2"), col("suffix_2"), col("media_corpus")))


    valids.write.mode(SaveMode.Overwrite).format("json").save(hdfs_dir)


  }

}

从错误开始的完整堆栈跟踪:

16/06/14 15:02:01 WARN TaskSetManager: Lost task 0.0 in stage 4.0 (TID 53, hdpd11n05.squaretwofinancial.com): org.apache.spark.SparkException: Task failed while writing rows.
    at org.apache.spark.sql.execution.datasources.DefaultWriterContainer.writeRows(WriterContainer.scala:272)
    at org.apache.spark.sql.execution.datasources.InsertIntoHadoopFsRelation$$anonfun$run$1$$anonfun$apply$mcV$sp$3.apply(InsertIntoHadoopFsRelation.scala:150)
    at org.apache.spark.sql.execution.datasources.InsertIntoHadoopFsRelation$$anonfun$run$1$$anonfun$apply$mcV$sp$3.apply(InsertIntoHadoopFsRelation.scala:150)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
    at org.apache.spark.scheduler.Task.run(Task.scala:89)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.io.IOException: org.apache.spark.SparkException: Failed to get broadcast_58_piece0 of broadcast_58
    at org.apache.spark.util.Utils$.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.ml.feature.CountVectorizerModel$$anonfun$9$$anonfun$apply$7.apply(CountVectorizer.scala:222)
    at org.apache.spark.ml.feature.CountVectorizerModel$$anonfun$9$$anonfun$apply$7.apply(CountVectorizer.scala:221)
    at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
    at scala.collection.mutable.WrappedArray.foreach(WrappedArray.scala:34)
    at org.apache.spark.ml.feature.CountVectorizerModel$$anonfun$9.apply(CountVectorizer.scala:221)
    at org.apache.spark.ml.feature.CountVectorizerModel$$anonfun$9.apply(CountVectorizer.scala:218)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.evalExpr43$(Unknown Source)
    at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
    at org.apache.spark.sql.execution.Project$$anonfun$1$$anonfun$apply$1.apply(basicOperators.scala:51)
    at org.apache.spark.sql.execution.Project$$anonfun$1$$anonfun$apply$1.apply(basicOperators.scala:49)
    at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
    at org.apache.spark.sql.execution.datasources.DefaultWriterContainer.writeRows(WriterContainer.scala:263)
    ... 8 more
Caused by: org.apache.spark.SparkException: Failed to get broadcast_58_piece0 of broadcast_58
    at org.apache.spark.broadcast.TorrentBroadcast$$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)
    ... 25 more

最佳答案

我遇到了类似的错误。

原来是CounterVectorModel中广播使用引起的。以下是我的案例的详细原因:

当调用model.transform() 时，词汇表被广播并隐式保存为模型中的属性broadcastDic。因此，如果在调用 model.transform() 后保存了 CounterVectorModel，则私有(private) var 属性 broadcastDic 也会被保存。但不幸的是，在 Spark 中，广播对象是上下文相关的，这意味着它是嵌入在 SparkContext 中的。如果该 CounterVectorModel 在不同的 SparkContext 中加载，它将无法找到之前保存的 broadcastDic。

因此，两种解决方案都是在保存模型之前阻止调用 model.transform()，或者通过方法 model.copy() 克隆模型。

关于scala - Spark Hadoop 广播失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37822567/