Hi Experts!
Is there a way to read first N messages from kafka stream and put them in
some collection and return to the caller for visualization purpose and close
spark streaming.
I will be glad to hear from you and will be thankful to you.
Currently I have following code that
def getsample(params: scala.collection.immutable.Map[String, String]): Unit
= {
if (params.contains("zookeeperQourum"))
zkQuorum = params.get("zookeeperQourum").get
if (params.contains("userGroup"))
group = params.get("userGroup").get
if (params.contains("topics"))
topics = params.get("topics").get
if (params.contains("numberOfThreads"))
numThreads = params.get("numberOfThreads").get
if (params.contains("sink"))
sink = params.get("sink").get
if (params.contains("batchInterval"))
interval = params.get("batchInterval").get.toInt
val sparkConf = new
SparkConf().setAppName("KafkaConsumer").setMaster("spark://cloud2-server:7077")
val ssc = new StreamingContext(sparkConf, Seconds(interval))
val topicMap = topics.split(",").map((_, numThreads.toInt)).toMap
var consumerConfig = scala.collection.immutable.Map.empty[String,
String]
consumerConfig += ("auto.offset.reset" -> "smallest")
consumerConfig += ("zookeeper.connect" -> zkQuorum)
consumerConfig += ("group.id" -> group)
var data = KafkaUtils.createStream[Array[Byte], Array[Byte],
DefaultDecoder, DefaultDecoder](ssc, consumerConfig, topicMap,
StorageLevel.MEMORY_ONLY).map(_._2)
val streams = data.window(Seconds(interval), Seconds(interval)).map(x =>
new String(x))
streams.foreach(rdd => rdd.foreachPartition(itr => {
while (itr.hasNext && size >= 0) {
var msg=itr.next
println(msg)
sample.append(msg)
sample.append("\n")
size -= 1
}
}))
ssc.start()
ssc.awaitTermination(5000)
ssc.stop(true)
}
Where sample is a StringBuilder, when I print the contents of this string
builder after getSample method call is returned. I got nothing in it.
Any help will be appreciated
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