火花流检查点恢复非常非常缓慢

时间:2016-07-15 07:43:57

标签: apache-spark amazon-s3 spark-streaming amazon-kinesis checkpointing

  • 目标:从Kinesis读取并通过spark streaming将数据以Parquet格式存储到S3。
  • 情况: 应用程序最初运行正常,运行1小时的批次,处理时间平均少于30分钟。出于某种原因,我们可以说应用程序崩溃了,我们尝试从检查点重新启动。处理现在需要永远,而不是前进。 我们尝试以1分钟的批处理间隔测试相同的东西,处理运行良好,批次完成需要1.2分钟。当我们从检查点恢复时,每批需要大约15分钟。
  • 注意: 我们正在使用s3作为检查站 使用1个执行器,带有19g mem&每个遗嘱执行人3个核心

附上截图:

首次运行 - 检查点恢复之前 Before checkpoint - Streaming Page

Before checkpoint - Jobs Page

Before checkpoint - Jobs Page2

尝试从检查点恢复: After checkpoint - Streaming Page After checkpoint - Jobs Page

Config.scala

object Config {

  val sparkConf = new SparkConf


  val sc = new SparkContext(sparkConf)

  val sqlContext = new HiveContext(sc)


  val eventsS3Path = sc.hadoopConfiguration.get("eventsS3Path")
  val useIAMInstanceRole = sc.hadoopConfiguration.getBoolean("useIAMInstanceRole",true)

  val checkpointDirectory =  sc.hadoopConfiguration.get("checkpointDirectory")

//  sc.hadoopConfiguration.set("spark.sql.parquet.output.committer.class","org.apache.spark.sql.parquet.DirectParquetOutputCommitter")

  DateTimeZone.setDefault(DateTimeZone.forID("America/Los_Angeles"))

  val numStreams = 2

  def getSparkContext(): SparkContext = {
    this.sc
  }

  def getSqlContext(): HiveContext = {
    this.sqlContext
  }





}

S3Basin.scala

object S3Basin {
  def main(args: Array[String]): Unit = {
    Kinesis.startStreaming(s3basinFunction _)
  }

  def s3basinFunction(streams : DStream[Array[Byte]]): Unit ={
    streams.foreachRDD(jsonRDDRaw =>{
      println(s"Old partitions ${jsonRDDRaw.partitions.length}")
      val jsonRDD = jsonRDDRaw.coalesce(10,true)
      println(s"New partitions ${jsonRDD.partitions.length}")

      if(!jsonRDD.isEmpty()){
        val sqlContext =  SQLContext.getOrCreate(jsonRDD.context)

        sqlContext.read.json(jsonRDD.map(f=>{
          val str = new String(f)
          if(str.startsWith("{\"message\"")){
            str.substring(11,str.indexOf("@version")-2)
          }
          else{
            str
          }
        })).registerTempTable("events")

        sqlContext.sql(
          """
            |select
            |to_date(from_utc_timestamp(from_unixtime(at), 'US/Pacific')) as event_date,
            |hour(from_utc_timestamp(from_unixtime(at), 'US/Pacific')) as event_hour,
            |*
            |from events
          """.stripMargin).coalesce(1).write.mode(SaveMode.Append).partitionBy("event_date", "event_hour","verb").parquet(Config.eventsS3Path)


        sqlContext.dropTempTable("events")
      }
    })
  }
}

Kinesis.scala

object Kinesis{


  def functionToCreateContext(streamFunc: (DStream[Array[Byte]]) => Unit): StreamingContext = {
    val streamingContext = new StreamingContext(Config.sc, Minutes(Config.sc.hadoopConfiguration.getInt("kinesis.StreamingBatchDuration",1)))   // new context
    streamingContext.checkpoint(Config.checkpointDirectory)   // set checkpoint directory
    val sc = Config.getSparkContext

    var awsCredentails : BasicAWSCredentials = null
    val kinesisClient = if(Config.useIAMInstanceRole){
      new AmazonKinesisClient()
    }
    else{
      awsCredentails = new BasicAWSCredentials(sc.hadoopConfiguration.get("kinesis.awsAccessKeyId"),sc.hadoopConfiguration.get("kinesis.awsSecretAccessKey"))
      new AmazonKinesisClient(awsCredentails)
    }


    val endpointUrl = sc.hadoopConfiguration.get("kinesis.endpointUrl")
    val appName = sc.hadoopConfiguration.get("kinesis.appName")

    val streamName = sc.hadoopConfiguration.get("kinesis.streamName")

    kinesisClient.setEndpoint(endpointUrl)
    val numShards = kinesisClient.describeStream(streamName).getStreamDescription().getShards().size

    val batchInterval = Minutes(sc.hadoopConfiguration.getInt("kinesis.StreamingBatchDuration",1))

    // Kinesis checkpoint interval is the interval at which the DynamoDB is updated with information
    // on sequence number of records that have been received. Same as batchInterval for this
    // example.
    val kinesisCheckpointInterval = batchInterval

    // Get the region name from the endpoint URL to save Kinesis Client Library metadata in
    // DynamoDB of the same region as the Kinesis stream
    val regionName = sc.hadoopConfiguration.get("kinesis.regionName")


    val kinesisStreams = (0 until Config.numStreams).map { i =>
        println(s"creating stream for $i")
        if(Config.useIAMInstanceRole){
          KinesisUtils.createStream(streamingContext, appName, streamName, endpointUrl, regionName,
            InitialPositionInStream.TRIM_HORIZON, kinesisCheckpointInterval, StorageLevel.MEMORY_AND_DISK_2)

        }else{
          KinesisUtils.createStream(streamingContext, appName, streamName, endpointUrl, regionName,
            InitialPositionInStream.TRIM_HORIZON, kinesisCheckpointInterval, StorageLevel.MEMORY_AND_DISK_2,awsCredentails.getAWSAccessKeyId,awsCredentails.getAWSSecretKey)

        }
      }

    val unionStreams = streamingContext.union(kinesisStreams)
    streamFunc(unionStreams)

    streamingContext
  }


  def startStreaming(streamFunc: (DStream[Array[Byte]]) => Unit) = {

    val sc = Config.getSparkContext

    if(sc.defaultParallelism < Config.numStreams+1){
      throw  new Exception(s"Number of shards = ${Config.numStreams} , number of processor = ${sc.defaultParallelism}")
    }

    val streamingContext =  StreamingContext.getOrCreate(Config.checkpointDirectory, () => functionToCreateContext(streamFunc))


//    sys.ShutdownHookThread {
//      println("Gracefully stopping Spark Streaming Application")
//      streamingContext.stop(true, true)
//      println("Application stopped greacefully")
//    }
//

    streamingContext.start()
    streamingContext.awaitTermination()


  }




}

DAG DAG

enter image description here

3 个答案:

答案 0 :(得分:2)

提出了一个Jira问题:https://issues.apache.org/jira/browse/SPARK-19304

问题是因为我们每次迭代读取的数据多于所需的数据,然后丢弃数据。通过为getResults aws call添加限制可以避免这种情况。

修复:https://github.com/apache/spark/pull/16842

答案 1 :(得分:0)

重新启动失败的驱动程序时,会发生以下情况:

  1. 恢复计算 - 检查点信息用于 重新启动驱动程序,重新构建上下文并重新启动所有 接收机。
  2. 恢复块元数据 - 将成为所有块的元数据 继续处理的必要条件将被恢复。
  3. 重新生成未完成的作业 - 对于处理该批处理的批次 没有完成由于失败,RDD和相应的 使用恢复的块元数据重新生成作业。
  4. 读取保存在日志中的块 - 执行这些作业时, 块数据直接从写入日志中读取。这恢复了 可靠保存到日志中的所有必要数据。
  5. 重新发送未确认的数据 - 未保存到的缓冲数据 失败时的日志将由来源再次发送。如 它没有得到接收方的承认。
  6. enter image description here 由于所有这些步骤都在驱动程序中执行,因此您的0个事件批次需要花费很多时间这应该发生在第一批只有事情才会正常。

    参考here

答案 2 :(得分:0)

之前我遇到过类似的问题,我的应用程序越来越慢。

尝试在使用rdd后释放内存,请致电rdd.unpersist() https://spark.apache.org/docs/latest/api/java/org/apache/spark/rdd/RDD.html#unpersist(boolean)

spark.streaming.backpressure.enabledtrue

http://spark.apache.org/docs/latest/streaming-programming-guide.html#setting-the-right-batch-interval

http://spark.apache.org/docs/latest/streaming-programming-guide.html#requirements

另外,请检查您的locality设置,可能会有太多数据移动。

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