在Eclipse：PySpark中执行时无法查看kafka消费者输出

Question

我在windows系统中安装了kafka和zookeeper。我已经启动了kafka和zookeeper服务器，创建了主题“javainuse-topic”，使用以下命令启动了producer和consumer

.\bin\windows\zookeeper-server-start.bat.\config\zookeeper.properties

.\bin\windows\kafka-server-start.bat.\config\server.properties

.\bin\windows\kafka-topics.bat--create-zookeeper localhost:2181-replication-factor 1-partitions 1-topic javainuse-topic

.\bin\windows\kafka-console-producer.bat--broker-list localhost:9092-topic javainuse-topic

.\bin\windows\kafka-console-consumer.bat--bootstrap-server localhost:9092-topic javainuse-topic--从开始

我能够成功地将数据从生产者传送到消费者。因此，我在eclipse中编写了下面的代码，并尝试在Local中执行它。但我无法在eclipse控制台中查看消费者数据。

import os
os.environ['PYSPARK_SUBMIT_ARGS'] = '--packages org.apache.spark:spark-streaming-kafka-0-8_2.11:2.3.0 pyspark-shell'

import sys
import time
from pyspark import SparkContext, SparkConf
from pyspark.streaming import StreamingContext
from pyspark.streaming.kafka import KafkaUtils


n_secs = 1
topic = "javainuse-topic"

conf = SparkConf().setAppName("KafkaStreamProcessor").setMaster("local[*]")
sc = SparkContext(conf=conf)
sc.setLogLevel("WARN")
ssc = StreamingContext(sc, n_secs)
    
kafkaStream = KafkaUtils.createDirectStream(ssc, [topic], {
                        'bootstrap.servers':'localhost:9092', 
                        'group.id':'javainuse-topic', 
                        'fetch.message.max.bytes':'15728640',
                        'auto.offset.reset':'largest'})
                        # Group ID is completely arbitrary

lines = kafkaStream.map(lambda x: x[1])
counts = lines.flatMap(lambda line: line.split(" ")).map(lambda word: (word, 1)).reduceByKey(lambda a, b: a+b)
counts.pprint()

ssc.start()
time.sleep(6) # Run stream for 10 minutes just in case no detection of producer
# ssc.awaitTermination()
ssc.stop(stopSparkContext=True,stopGraceFully=True)

Answer 1

您可以重试，但这次将auto.offset.reset设置为“最早”（如果使用的是旧使用者，则为“最小”)。

kafkaStream = KafkaUtils.createDirectStream(ssc, [topic], {
                        'bootstrap.servers':'localhost:9092', 
                        'group.id':'javainuse-topic', 
                        'fetch.message.max.bytes':'15728640',
                        'auto.offset.reset':'earliest'})
                        # Group ID is completely arbitrary