Kafka连接SparkStreaming的两种方式

第一种方式代码:

 1 import org.apache.spark.storage.StorageLevel
 2 import org.apache.spark.{HashPartitioner, SparkConf}
 3 import org.apache.spark.streaming.kafka.KafkaUtils
 4 import org.apache.spark.streaming.{Seconds, StreamingContext}
 5 
 6 object KafkaWordCount {
 7   val updateFunc = (iter: Iterator[(String, Seq[Int], Option[Int])]) => {
 8     //iter.flatMap(it=>Some(it._2.sum + it._3.getOrElse(0)).map(x=>(it._1,x)))
 9     iter.flatMap { case (x, y, z) => Some(y.sum + z.getOrElse(0)).map(i => (x, i)) }
10   }
11 
12   def main(args: Array[String]) {
13     LoggerLevels.setStreamingLogLevels()
14     val Array(zkQuorum, group, topics, numThreads) = args
15     val sparkConf = new SparkConf().setAppName("KafkaWordCount").setMaster("local[2]")
16     val ssc = new StreamingContext(sparkConf, Seconds(5))
17     ssc.checkpoint("c://ck2")
18     //"alog-2016-04-16,alog-2016-04-17,alog-2016-04-18"
19     //"Array((alog-2016-04-16, 2), (alog-2016-04-17, 2), (alog-2016-04-18, 2))"
20     val topicMap = topics.split(",").map((_, numThreads.toInt)).toMap
21     val data = KafkaUtils.createStream(ssc, zkQuorum, group, topicMap, StorageLevel.MEMORY_AND_DISK_SER)
22     val words = data.map(_._2).flatMap(_.split(" "))
23     val wordCounts = words.map((_, 1)).updateStateByKey(updateFunc, new HashPartitioner(ssc.sparkContext.defaultParallelism), true)
24     wordCounts.print()//老师给的代码文件中没有这句话  必须要有一个Action,否则报错
25     //java.lang.IllegalArgumentException: requirement failed: No output operations registered, so nothing to execute
26     ssc.start()
27     ssc.awaitTermination()
28   }
29 }

第二种方式代码:

 1 import kafka.serializer.StringDecoder
 2 import org.apache.log4j.{Level, Logger}
 3 import org.apache.spark.SparkConf
 4 import org.apache.spark.rdd.RDD
 5 import org.apache.spark.streaming.kafka.{KafkaManager, KafkaUtils}
 6 import org.apache.spark.streaming.{Seconds, StreamingContext}
 7 
 8 
 9 object DirectKafkaWordCount {
10 
11   /*  def dealLine(line: String): String = {
12       val list = line.split(',').toList
13   //    val list = AnalysisUtil.dealString(line, ',', '"')// 把dealString函数当做split即可
14       list.get(0).substring(0, 10) + "-" + list.get(26)
15     }*/
16 
17   def processRdd(rdd: RDD[(String, String)]): Unit = {
18     val lines = rdd.map(_._2)
19     val words = lines.map(_.split(" "))
20     val wordCounts = words.map(x => (x, 1L)).reduceByKey(_ + _)
21     wordCounts.foreach(println)
22   }
23 
24   def main(args: Array[String]) {
25     if (args.length < 3) {
26       System.err.println(
27         s"""
28            |Usage: DirectKafkaWordCount   
29            |   is a list of one or more Kafka brokers
30            |   is a list of one or more kafka topics to consume from
31            |   is a consume group
32            |
33         """.stripMargin)
34       System.exit(1)
35     }
36 
37     Logger.getLogger("org").setLevel(Level.WARN)
38 
39     val Array(brokers, topics, groupId) = args
40 
41     // Create context with 2 second batch interval
42     val sparkConf = new SparkConf().setAppName("DirectKafkaWordCount")
43     sparkConf.setMaster("local[*]")
44     sparkConf.set("spark.streaming.kafka.maxRatePerPartition", "5")
45     sparkConf.set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
46 
47     val ssc = new StreamingContext(sparkConf, Seconds(2))
48 
49     // Create direct kafka stream with brokers and topics
50     val topicsSet = topics.split(",").toSet
51     val kafkaParams = Map[String, String](
52       "metadata.broker.list" -> brokers,
53       "group.id" -> groupId,
54       "auto.offset.reset" -> "smallest"
55     )
56 
57     val km = new KafkaManager(kafkaParams)
58 
59     val messages = km.createDirectStream[String, String, StringDecoder, StringDecoder](
60       ssc, kafkaParams, topicsSet)
61 
62     messages.foreachRDD(rdd => {
63       if (!rdd.isEmpty()) {
64         // 先处理消息
65         processRdd(rdd)
66         // 再更新offsets
67         km.updateZKOffsets(rdd)
68       }
69     })
70 
71     ssc.start()
72     ssc.awaitTermination()
73   }
74 }

关于第二种方式可以参考:

http://blog.csdn.net/ligt0610/article/details/47311771