我正在开发Spark Streaming API,我希望连续流式传输一组预先下载的Web日志文件,以模拟实时流。我编写了一个脚本,用于压缩压缩日志并将输出通过端口7777传输到nc。
脚本如下所示:
BASEDIR=/home/mysuer/data/datamining/internet_traffic_archive
zipped_files=`find $BASEDIR -name "*.gz"`
for zfile in $zipped_files
do
echo "Unzipping $zfile..."
gunzip -c $zfile | nc -l -p 7777 -q 20
done
我有用Scala编写的流代码来处理流。它在大多数情况下运行良好,但是当它用完文件流时它似乎出现以下错误:
16/02/19 23:04:35 WARN ReceiverSupervisorImpl:
Restarting receiver with delay 2000 ms: Socket data stream had no more data
16/02/19 23:04:35 ERROR ReceiverTracker: Deregistered receiver for stream 0:
Restarting receiver with delay 2000ms: Socket data stream had no more data
16/02/19 23:04:35 WARN BlockManager: Block input-0-1455941075600 replicated to only 0 peer(s) instead of 1 peers
....
16/02/19 23:04:40 ERROR Executor: Exception in task 2.0 in stage 15.0 (TID 47)
java.util.NoSuchElementException: None.get
at scala.None$.get(Option.scala:313)
at scala.None$.get(Option.scala:311)
at com.femibyte.learningsparkaddexamples.scala.StreamingLogEnhanced$$anonfun$2.apply(StreamingLogEnhanced.scala:42)
at com.femibyte.learningsparkaddexamples.scala.StreamingLogEnhanced$$anonfun$2.apply(StreamingLogEnhanced.scala:42)
如何实现正常关闭,以便程序在不再检测到流中的任何数据时正常退出?
我的scala代码如下所示:
object StreamingLogEnhanced {
def main(args: Array[String]) {
val master = args(0)
val conf = new SparkConf().setMaster(master).setAppName("StreamingLogEnhanced")
// Create a StreamingContext with a n second batch size
val ssc = new StreamingContext(conf, Seconds(10))
// Create a DStream from all the input on port 7777
val log = Logger.getLogger(getClass.getName)
sys.ShutdownHookThread {
log.info("Gracefully stopping Spark Streaming Application")
ssc.stop(true, true)
log.info("Application stopped")
}
val lines = ssc.socketTextStream("localhost", 7777)
// Create a count of log hits by ip
var ipCounts=countByIp(lines)
ipCounts.print()
// start our streaming context and wait for it to "finish"
ssc.start()
// Wait for 600 seconds then exit
ssc.awaitTermination(10000*600)
ssc.stop()
}
def countByIp(lines: DStream[String]) = {
val parser = new AccessLogParser
val accessLogDStream = lines.map(line => parser.parseRecord(line))
val ipDStream = accessLogDStream.map(entry => (entry.get.clientIpAddress, 1))
ipDStream.reduceByKey((x, y) => x + y)
}
}