Hello,
I am trying to perform a POC between Kafka 0.10 and Spark 2.0.2. Currently I
am running into an issue, where only one executor ("kafka consumer") is
reading from the topic. Which is causing performance to be really poor. I
have tried adding "--num-executors 8" both in the script to execute the jar
and in my java code. Here is the code below. Please let me know if I am
missing something or there is a way to increase the number of consumers to
connect to kafka.
Thanks,
Gabe
<code>
Map<String, Object> kafkaParams = new HashMap<>();
kafkaParams.put( "bootstrap.servers", "server:9092" );
kafkaParams.put( "key.deserializer", StringDeserializer.class );
kafkaParams.put( "value.deserializer", StringDeserializer.class
);
kafkaParams.put( "group.id", "spark-aggregation" );
kafkaParams.put( "auto.offset.reset", "earliest" );
kafkaParams.put( "request.timeout.ms", "305000" );
kafkaParams.put( "heartbeat.interval.ms", "85000" );
kafkaParams.put( "session.timeout.ms", "90000" );
Collection<String> topics = Arrays.asList( "Topic" );
SparkConf sparkConf = new SparkConf().setMaster(
"spark://server:7077" )
.setAppName( "aggregation" ).set(
"spark.submit.deployMode", "cluster" )
.set( "spark.executor.instances", "16" );
JavaStreamingContext javaStreamingContext = new
JavaStreamingContext(
sparkConf, new Duration( 5000 ) );
//Creates connect to the Stream.....
final JavaInputDStream<ConsumerRecord<String, String>>
stream =
KafkaUtils.createDirectStream(
javaStreamingContext,
LocationStrategies.PreferConsistent(),
ConsumerStrategies.<String, String> Subscribe(
topics, kafkaParams ) );
//JavaPairDStream<String, String> unifiedStream =
javaStreamingContext.union(kafkaStreams.get(0), kafkaStreams.subList(1,
kafkaStreams.size()));
JavaDStream<String> records = stream.map( new
Function<ConsumerRecord<String, String>, String>() {
private static final long serialVersionUID = 1L;
@Override
/**
* Pulling key from the stream and creating the
aggregation key.
*/
public String call( ConsumerRecord<String, String>
record ) {
return record.key();
}
} );
JavaPairDStream<String, Integer> pairs = records.mapToPair( new
PairFunction<String, String, Integer>() {
private static final long serialVersionUID = 1L;
@Override
/**
* Creating new tuple to perform calculations on.
*/
public Tuple2<String, Integer> call( String s ) {
return new Tuple2<>( s, 1 );
}
} );
JavaPairDStream<String, Integer> counts = pairs.reduceByKey( new
Function2<Integer, Integer, Integer>() {
private static final long serialVersionUID = 1L;
@Override
/**
* perform counts...
*/
public Integer call( Integer i1, Integer i2 ) {
return i1 + i2;
}
} );
stream.foreachRDD( new
VoidFunction<JavaRDD<ConsumerRecord<String,
String>>>() {
/**
*
*/
private static final long serialVersionUID = 1L;
@Override
public void call( JavaRDD<ConsumerRecord<String,
String>> rdd ) {
OffsetRange[] offsetRanges = (
(HasOffsetRanges) rdd.rdd()
).offsetRanges();
// some time later, after outputs have completed
( (CanCommitOffsets) stream.inputDStream()
).commitAsync( offsetRanges
);
}
} );
</code>
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