Spark Streaming初試

Spark Streaming初試

yum install nc.x86_64

./bin/spark-shell --total-executor-cores 34 

敲入下面程序：

import org.apache.spark.SparkConf

import org.apache.spark.streaming.{Seconds, StreamingContext}

import org.apache.spark.storage.StorageLevel

    val ssc = new StreamingContext(sc, Seconds(1))

    val lines = ssc.socketTextStream("hostname", 9999, StorageLevel.MEMORY_AND_DISK_SER)

    val words = lines.flatMap(_.split(" "))

    val wordCounts = words.map(x => (x, 1)).reduceByKey(_ + _)

    wordCounts.print()

    ssc.start()

    ssc.awaitTermination()

    

    

在hostname機器，安裝nc後，nc -lk 9999

不斷輸入字符，例如hello world，會在啓動spark-shell的機器不斷統計每次輸入數據的字符頻率統計。  

   

   參考 

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

    https://github.com/apache/spark/blob/master/examples/src/main/scala/org/apache/spark/examples/streaming/NetworkWordCount.scala