I run the spark own Wordcount example, why only after the CTRL + C, will only be on the command line output? Even if the print () into saveastextfile and write files only after interruption program, consult everybody what reason is this?
The code is as follows:
The object KafkaWordCount {
Def main (args: Array [String]) {
If (args. Length & lt; 4) {
System. Err. Println (" the Usage: KafkaWordCount & lt; ZkQuorum> " )
System. The exit (1)
}

StreamingExamples. SetStreamingLogLevels ()

Val Array (zkQuorum, group, switchable viewer, numThreads)=args
Val sparkConf=new sparkConf (). SetAppName (" KafkaWordCount ")
Val SSC=new StreamingContext (sparkConf, Seconds (2))
SSC. Checkpoint (" checkpoint ")

Val topicMap=switchable viewer. The split (", "). The map ((_, numThreads. ToInt)). ToMap
Val lines.=KafkaUtils createStream (SSC, zkQuorum, group, topicMap). The map (_) _2)
Val words=lines. FlatMap (_. The split (" "))
Val wordCounts=words. The map (x=& gt; (1) l, x)
ReduceByKeyAndWindow (+ _ _, _ - _, Minutes (10), Seconds (2), 2)
WordCounts. Print ()

SSC. Start ()
SSC. AwaitTermination ()
}
}