1.Spark Streaming功能介绍
1）定义
Spark Streaming is an extension of the core Spark API that enables scalable, high-throughput, fault-tolerant stream processing of live data streams
2.NC服务安装并运行Spark Streaming
1）在线安装nc命令
yum install -y nc
2）运行Spark Streaming 的WordCount
bin/run-example streaming.NetworkWordCount localhost 9999
3）把文件通过管道作为nc的输入，然后观察spark Streaming计算结果
cat test.txt | nc -lk 9999
文件具体内容
hadoop storm spark
hbase spark flume
spark dajiangtai spark
hdfs mapreduce spark
hive hdfs solr
spark flink storm
hbase storm es
3.Spark Streaming工作原理
1）Spark Streaming数据流处理
2）接收器工作原理
3）综合工作原理
4.Spark Streaming编程模型
1）StreamingContext初始化的两种方式
#第一种
val ssc = new StreamingContext(sc, Seconds(5))
#第二种
val conf = new SparkConf().setMaster("local[2]").setAppName("NetworkWordCount")
val ssc = new StreamingContext(conf, Seconds(1))
2）Spark Streaming socket代码
object NetworkWordCount {
def main(args: Array[String]) {
if (args.length < 2) {
System.err.println("Usage: NetworkWordCount ")
System.exit(1)
}
//创建StreamingContext，每秒钟计算一次
val sparkConf = new SparkConf().setAppName("NetworkWordCount")
val ssc = new StreamingContext(sparkConf, Seconds(1))
//监听网络端口，参数一：hostname 参数二：port 参数三：存储级别，创建了lines流
val lines = ssc.socketTextStream(args(0), args(1).toInt, StorageLevel.MEMORY_AND_DISK_SER)
//flatMap运算
val words = lines.flatMap(_.split(" "))
//map reduce 计算
val wordCounts = words.map(x => (x, 1)).reduceByKey(_ + _)
wordCounts.print()
ssc.start()
ssc.awaitTermination()
}
}
5.Spark Streaming读取Socket流数据
1）spark-shell运行Streaming程序，要么线程数大于1，要么基于集群。
bin/spark-shell --master local[2]
bin/spark-shell --master spark://bigdata-pro01.kfk.com:7077
2）spark 运行模式
3）Spark Streaming读取Socket流数据
a）编写测试代码，并本地运行
object TestStreaming {
def main(args: Array[String]) {
if (args.length < 2) {
System.err.println("Usage: NetworkWordCount ")
System.exit(1)
}
val spark=SparkSession.builder().master("local[2]").setAppName("streaming").getOrCreate()
val sc = spark.SparkContext
val ssc = new StreamingContext(sc, Seconds(5))
//监听网络端口，参数一：hostname 参数二：port 参数三：存储级别，创建了lines流
val lines = ssc.socketTextStream("igdata-pro02.kfk.com", 9999, StorageLevel.MEMORY_AND_DISK_SER)
//flatMap运算
val words = lines.flatMap(_.split(" "))
//map reduce 计算
val wordCounts = words.map(x => (x, 1)).reduceByKey(_ + _)
wordCounts.print()
ssc.start()
ssc.awaitTermination()
}
}
b）启动nc服务发送数据
nc -lk 9999
6.Spark Streaming保存数据到外部系统
1）保存到mysql数据库
2）保存到hdfs
7.Spark Streaming与Kafka集成
1）Maven引入相关依赖：spark-streaming-kafka
2）编写测试代码并启动运行
object StreamingKafka8 {
def main(args: Array[String]): Unit = {
val spark = SparkSession.builder()
.master("local[2]")
.appName("streaming").getOrCreate()
val sc =spark.sparkContext;
val ssc = new StreamingContext(sc, Seconds(5))
// Create direct kafka stream with brokers and topics
val topicsSet =Set("weblogs")
val kafkaParams = Map[String, String]("metadata.broker.list" -> "bigdata-pro01.kfk.com:9092")
val kafkaStream = KafkaUtils.createDirectStream[String, String, StringDecoder, StringDecoder](
ssc, kafkaParams, topicsSet)
val lines = kafkaStream.map(x => x._2)
val words = lines.flatMap(_.split(" "))
val wordCounts = words.map(x => (x, 1L)).reduceByKey(_ + _)
wordCounts.print()
ssc.start()
ssc.awaitTermination()
}
}
3）启动Kafka服务并测试生成数据
bin/kafka-server-start.sh config/server.properties
bin/kafka-console-producer.sh --broker-list bigdata-pro01.kfk.com --topic weblogs
